Many of the problems of the
Calgary Garden can be overcome by the proper selection of the site for any landscape or garden endeavour. When planning for a vegetable garden, one should try to choose a site that slopes to the south or southwest. This slope ensures an abundant supply of sunshine and, at the same time, allows for the drainage of cold air
down slope. Do not situate the garden at the lowest point of the property.
should be provided to the north, west and east if possible to protect the garden against the winds and to increase the soil and air temperatures by trapping the heat of the sun. The site should be open to the south and at the lowest point to allow the cold air free passage to lower areas and out of the garden. The windbreak should be at least 20 feet (6m) from the garden for maximum efficiency, and to ensure that the roots of the windbreak do not compete excessively with the garden for nutrients and water. A site situated as above will warm earlier in the spring and will be less susceptible to the early fall frosts.
When choosing a site for the Calgary orchard, on the other hand, the site would be better situated on a north or east facing slope. This will reduce the danger of rapid fluctuations in temperature which damages the trees and will reduce sunscald from the low winter sun. A north or east exposure also delays the opening of fruit tree blossoms and thereby reduces the risk of damage from late spring frost and subsequent loss of fruit. A windbreak is necessary, just as in the garden, and will improve pollination and builds up heat that aids in maturation of the fruit in the fall.
Choosing a site for Calgary landscaping is not always possible. In most instances the site for the home has already been decided upon without regard to any landscaping requirements. When possible, site your home to take advantage of the best possible exposure for the front yard. This will make the selection of landscape material much easier. If the home is already established on the site, the material must be selected to suit the existing exposure. For a north facing home, the foundation plantings must, of necessity, be chosen from material that will tolerate the shade. Windbreaks, fences and buildings all combine to change the micro-climate of the site. This must be taken into consideration when landscaping the site. This will be discussed in greater detail later on.
In all cases of Calgary site location, always attempt to avoid low areas where frost accumulates, especially concave slopes, basins, depressions, and other poorly drained areas where frost will collect sooner. Avoid areas where the flow of cold air downslope is hindered by barriers of any type including plant material, fences, buildings etc. An upland ridge or plateau adjacent to a low area is preferable to a flat, low area.
EXTENDING THE SEASON
To aid the Calgary grower much research has been done in developing ways to extend the growing season by the use of mulches, row covers, portable greenhouses, plant shelters, cold frames, hot beds, as well as individual plant covers.
A: MULCHES IN CALGARY
Mulches can be used alone or in combination with other equipment to raise the soil temperature, reduce competition from weeds and reduce moisture loss. Mulches are of several types. Both clear and black polyethylene have been used but not with equal results. Black is good for suppressing weed growth but is not as effective in raising soil temperature as clear poly. Both create a litter problem as they do not decompose and they must be gathered up for disposal. There are some biodegradable mulches available that are supposed to last for one season and should decompose by fall. In my own experience in the north, they do not last until harvest due to the long hours of sunlight in the summer. They decompose early in the season and become ineffective for weed control and moisture retention. Some books recommend organic mulches to control weeds but in the north they act as insulation and keep the soil too cool and inhibit good growth. During tests at Fort Chimo, Quebec in 1964-65, it was shown that a covering or mulch of organic matter kept the soil much cooler than either bare soil or soil under a grass cover. At a depth of 4" (10cm),the soil temperature was 59.6°F (15.3°C) for bare cultivated ground, and 65.2°F (18.4°C) for uncultivated ground but only 41.1°F (5°C) where a covering of sphagnum moss existed. Although moss has a low thermal conductivity rating when dry, it has a large capacity for absorbing and holding moisture. In daytime this moisture is lost rapidly and this results in a high heat loss as vaporization of water requires heat. The soil is cooling when it should be accumulating warmth. If organic mulches are used, they should not be applied until the soil has warmed sufficiently, at least July.
To increase the air temperature, many different methods have been developed. They range from individual plant covers to plant shelters that are temporary greenhouses. Individual covers may be as simple as a plastic bottle with its bottom cut out. The cap is opened and closed as necessary to control heat buildup. Many types of plant covers are available through nurseries and garden centres. They range from economical devices such as Hotkaps to one of the newest, the Igloo.
B: CALGARY ROW COVERS
Row covers are another product that is widely available. They range from small plastic and poly units for $5 to models costing $40. In many cases the poly must be replaced yearly unless extreme care is taken in handling and storage. Some of these row covers have slit poly covers. These row covers are designed to provide ventilation to eliminate daily opening and closing of the poly. The frost protection from them is not as good as with solid covers. Only 28-29°F (-2°C) can be endured, therefore they should not be relied upon for protection from heavy frosts but should only be used for a 10 to 14 day headstart on the season.
By combining mulches with row covers, not only is the air temperature increased, but the soil temperature is higher than with either of them alone. This increase of between 6-8°F (3.3-4.5°C) can extend the season by weeks, and ensure a successful garden.
Unfortunately there is one crop that cannot be aided by row covers if cloudy, cool weather persists for an extended period of time. Vine crops tend to wilt when the sunny weather returns because the uptake of water was prevented by the cool soil temperatures that result from the extended cool weather.
Hotkaps come in several designs and sizes but esentially they are the same. They are made of treated paper, the larger sizes being supported by wire. They are set over the plant and soil used to hold them in place. The smaller ones, usually available in most catalogues and garden centres, are too small for all but the shortest of time. They are quickly outgrown. They are also very susceptible to crushing by the late snows common to the north. For ventilation, they must be torn open and this then makes them useless for frost protection. If frosts threaten, another cover will then have to be applied. Hotkaps give only 2-3 degrees of protection.
D: PLASTIC IGLOOS
The Plastic Igloo is a new development patented by a Toronto biologist. It is a plastic tetrahedron (3 sided pyramid), 18" tall (45.7cm) and filled with water. They are placed over the plants and the 4" layer of water acts as insulation even when it freezes. Experiments indicate that even when the outside temperature was as low as zero, Fahrenheit, the inside temperature never fell below 28°F (-2.2°C). This would provide a safe method of overwintering semi-hardy plant material as well. The only source of the Igloo that I know of at present is C. A. Cruikshank Inc. and they cost $2.60 each. They are reusable so the cost per year is not really that high compared to Hotkaps which are a one-time only product.
Sunhats are another reusable product. They are cones of clear rigid plastic, 9 1/4" (23.5 cm) high. Green striping provides a shifting pattern of shade throughout the day. The plants are also protected from the hot sun by a moisture film on the inside of the sunhat. A hole in the top provides ventilation. They create a miniature greenhouse for the plant, protecting it from weather and insects while conserving moisture and increasing soil temperature. This increases the growth rate of the plant. Sunhats are one of my standard protectors. Their taller height makes them more desirable for taller plants than Hotkaps. If severe frosts threaten, the hole in the top can be covered with a small plastic bag, or poly thrown over the whole row. They cost $.80 each and more than save that much in a few years.
F: TOMATO HOODS IN CALGARY
Tomato hoods or jackets are another product that finds regular use in my garden. They consist of a length of tubular plastic film with vent holes. It is cut to length and placed over the plant and stake. The top is gathered and secured to the stake. As the season progresses, the tube can be raised up higher on the stake. The film not only protects the plants from minor spring frosts, but it also retains warmth to aid in ripening the tomatoes. It is reusable with care and is relatively inexpensive. It costs $6 for enough film to cover from 6 to 10 plants. Besides its advantages in heat retention, it is excellent protection for the tomatoes from hail damage. It is only removed during periods of extreme heat and then it only has to be rolled up and secured to the stake. When the temperature cools, unroll it and it is back to work. The only problem I have had so far with the film is slugs. They tend to find the shelter of the hoods attractive and bait must be used to control them.
G: RUMSEY CLOCHE CLIPS
Rumsey Cloche Clips are an aid to making you own plant shelters. They are rubber and aluminum clips designed to hold two pieces of glass or plastic together in the form of a tent, thus creating a mini-greenhouse for the plant. They are very expensive, 6 for $8.95. I have seen them used to create a long solid row cover that is easily dissassembled. For this use, they can be put further apart and this will reduce the number needed.
H: PLANT CAPES IN CALGARY
Plant Capes are a different type of plant protector. They are made of the same material as the Sunhats. They are a collar that is placed around the stem of the plant. They conserve moisture, increase soil temperature, and direct water to the roots of the plants. They reduce weeds and slug damage. They adjust as the plant grows. They are not for frost protection.
I: PORTABLE GREENHOUSES IN CALGARY
Most catalogues list portable greenhouses and their prices range from approximately $200 to around $400 for most units depending upon size. There seems to be little difference in price from one company to the next for a similar greenhouse, although some charge shipping charges as well.
Gerard H. Gubbels, who was a horticulturist at Mile 1019 Experimental Farm when it was operational, wrote a pamphlet describing the construction and erection of portable crop shelters that can be made in sections and erected in the field. These are built to be dissassembled and stored from year to year.
J: COLD FRAMES AND HOT BEDS IN CALGARY
Cold frames can range from inexpensive home built units to ready-to-assemble kits that tend to be very expensive. MacFayden lists a soft plastic cold frame for $35 to $40 and a solid one from $90 to $160. The booklet "Container Gardening" (Ag Canada pub. 1653) has plans for several different designs of cold frames which could be built economically and are much more efficient than the kits.
Hot beds are generally cold frames that have been heated by either biological methods or heating cables. The cheapest method of heating a hot bed is with manure. Raw manure generates considerable heat when it is decomposing. It is for this reason that it should never be used around plants until it is decomposed or well rotted. By putting this characteristic to use, many people get that extra early start on spring without the expense of a greenhouse. There are several drawbacks, though, to using raw manure. First is that it is odorous and this can create a problem in urban areas. Also, it is not always readily available.
One method of overcoming the problem of heating a hot bed is by the use of soil heating cables. These cables are similar to the ones used to melt snow off your eaves in the winter or to prevent your water lines from freezing. They are thermostatically controlled to provide the proper heat level that plant roots require. Plants can withstand lower air temperatures as long as the soil temperature is kept optimum. These cables are also useful for providing bottom heat to aid in seed germination.
Many of the devices mentioned in this section can be economically provided or created with a little ingenuity. The key is to make gardening enjoyable as well as rewarding by ensuring crop success.
WINTER PROTECTION IN CALGARY
Now that you have ensured that your plant material has entered winter in a dormant condition, don't think that your responsibility for the year has ended. A few precautions on your part will increase the plant's chances of successfully wintering over. For perennials, including flowers and vegetables, a winter mulch will be required in many cases to protect them from the freeze-thaw cycles common to winter. It will insulate the ground to prevent premature thawing and moderate the soil temperature to prevent root damage. A mulch also holds the snow which also acts as an insulator. Even some of the hardier vegetables can be stored in the row by the use of a mulch of straw. Mulching of the shrub and evergreen border is also advised. Some plants do not require mulching and some do not tolerate mulching. For plants that do not tolerate mulching, protection can be provided by inverting baskets over the plant and a weight used to hold it in place. Some tender plants must be over-wintered in the cold-frame. The Igloo, mentioned earlier, can also be used to over-winter half hardy plant material. Bonsai material should be over-wintered in a coldframe or cold cellar to provide the winter dormancy required but prevent damage.
For roses, a mulch is not sufficient. When the ground is frozen, the plants must be mounded with 8 to 12" (20-30 cm) of dry material such as soil, peat moss, or sawdust. Tests in Manitoba show that dry sawdust and granular peat worked better than soil. This mound is then covered with straw or evergreen boughs. Chicken wire, boxes, and cylinders of tar paper are some of the methods used to keep the protection in place. Fiberglass batting has been used to provide insulation. To help keep the material dry, cover it with 1 mil polyethylene. Evergreen boughs are an excellent way to trap snow for further insulation. It is a good use for that Christmas tree rather than burning it or filling up the local dump.
Another method of over-wintering roses in Calgary is to dig them and store them in a cold cellar or pit. Dig a trench 36" deep (90 cm) in a shady location. Lay the roses in the trench just before the ground freezes. Put moist soil around the roots to prevent drying. Fill the trench with loose soil. Cover with straw or evergreen boughs. A grower in Edmonton, Alberta grows over 300 tender roses each year with very little winter kill. In 1979, he lost only 7 out of 300 bushes and in 1980, only 5 out of 315 bushes. He has developed his own method of planting which I will discuss later under a section on Roses. His experience has shown that northerners do not simply have to yearn when we look at those beautiful roses in the catalogues. We can grow them and over-winter them successfully with the proper planting and care.
Trees in Calgary, including fruit trees, require different types of winter protection. The harsh winter sun causes sunscald.
Chinooks cause alternate freezing and thawing of the bark and sap causing much damage, even premature budding out. Strong winter winds dessicate trees and shrubs. Late spring frosts damage flower and fruit buds. Trees with thin bark should not be placed where they will receive the west and south-west winter sun. The heat and light from the bright sun causes blistering and sunscald. It causes the sap to thaw and flow only to refreeze rupturing the plant tissues. These trees should be planted on the north side of the building if possible. If this is not possible, precautions must be taken. Covering the main trunk and branches with building paper, aluminum foil, tree wraps or even a heavy coat of latex paint will help reduce sun problems. Planting the orchard on a north slope is recommended to overcome this problem and slow down budding in the spring.
Evergreens in Calgary do not suffer from the same problems as deciduous trees. They do not seem to be bothered by trunk damage due to the shade provided by their own foliage but they are very susceptible to dessication caused by the drying effect of the wind and sun. Water loss exceeds the uptake of water by the roots. This becomes a serious problem if the trees went into winter without adequate water reserves. This happens if irrigation is not available during droughts, or the trees were transplanted in the fall and did not have sufficient time to develop a new root system. The use of anti-dessicants such as Wilt-Pruf will give some protection from desication. Evergreens are also very susceptible to damage from the weight of snow and ice. Evergreens used in foundation plantings suffer from the ice and snow from the eaves of lthe building. Quite often they are crushed and broken unless some sort of protection was provided. Upright evergreens should be wrapped in burlap or netting to prevent the branches from being weighted down from the snow. Low growing evergreens should have a roof of some sort erected over them to prevent crushing. Where snow load is not a problem, evergreens can be given shade from the winter sun, protection from salt spray, etc. by burlap wrapped around stakes.
Here are some diagrams of methods of protecting your plants over winter.
Content provided by
Patricia Chenier Smith
PREPARING THE SITE
Probably the most important part of the site is the soil. The soil can affect plant material in many ways. If the soil is hard, and poorly drained it will be cold in spring. Sandy soil, on the other hands, will warm sooner but will not retain heat in the fall and therefore will result in the danger of early frost. Ideally, the soil should be a loam or clay loam with no salinity or evidence of a high water table. Work the soil in the fall to allow it to warm sooner in the spring, hold snow melt moisture better and drain properly to prevent excess moisture. The condition of the soil should be improved by adding organic matter but, when adding organic matter in the fall, it should be well decomposed. Too much raw organic matter will cause the soil to be slow to warm up in the spring as it holds frost much longer.
Fall is also the time to have your soil tested. Soil fertility and pH can best be adjusted if an accurate picture of the nutrient levels are known. An accurate assessment of nitrogen levels is doubly important. There must be sufficient nitrogen for good growth, especially in the spring, but too much would result in delayed maturity. This could often mean the difference between a crop being ready for harvest before the first killing frost or a whole season's work lost. Adequate amounts of phosphorus will offset the effect of nitrogen to a great degree and will hasten maturity.
To ensure a successful garden crop or the survival of landscape material, proper planting techniques should be used. In some instances, special techniques are necessary. Spring is the best time to plant material in the north. This ensures good root growth before winter sets in. Fall planted material tends to suffer from winter damage to a great degree. This is especially true with evergreens. The time from leaf drop to freeze up is very short in the north and does not give sufficient time to dig the material, ship it, plant it and ensure good root development before winter, which in the north can be as early as October. This results in insufficient root mass to offset the water loss due to drying winds and is the cause of most failures when fall planting. There are some exceptions, though. Certain perennials are best planted in the fall. These include peonies and hardy lilies, which move best in mid-September and up to mid-October for lilies; and bearded iris, oriental poppies and bleeding-heart which prefer early August.
In the vegetable garden, the key to success in Calgary is to start planting the hardy and cool season vegetables as soon as the ground can be worked. They will then have sufficient time to mature. For the tender types, they must be started indoors and transplanted out after all danger of frost has passed or else special techniques and equipment used to ensure their survival should frosts occur. I will cover these techniques and equipment later. Seeding of hardy vegetables can sometimes be started as early as late April in the north but the second week of May is the average. There are still people who think that nothing can go in the ground before the 24th of May weekend. Most cool weather crops prefer the early start and should mature before the heat of summer for best crop results. Some people seed onions, parsnip and carrot the previous fall for early germination. Fast growing vegetables should be sown at intervals of 10 to 14 days to ensure a long crop season. Planting varieties that mature at different rates also spreads the harvest over a longer period of time. To increase soil temperatures, especially in permafrost areas, use ridging or terracing when planting. Ridging can raise the soil temperature by 2.2°C (4°F) and combined with poly mulches will increase the temperature by up to 9°C (16°F). This can facilitate earlier planting of most seeds and is especially good for plants who do not tolerate cold feet such as potatoes. Adequate moisture should be available at planting time for germination. In the early spring, soil moisture is usually higher than later in the spring if rainfall is low. This is another reason to plant as early as possible.
THE SHELTERBELT OR WINDBREAK
Everybody, nowadays, is familiar with the effects of wind on temperature. The wind chill factor is a commonplace topic in winter weather reports. Plants, animals, and even your home suffer from the affects of windchill just as you do. If you reduce the wind velocity, you reduce the affect it has on temperature. This reduction is accomplished by windbreaks, shelterbelts and fences.
Windbreaks and shelterbelts, by reducing the wind velocity, encourage the deposition of snow to the windward side of the strip, and reduce the deposition of snow on the leeward side. They also provide other benefits. The evaporation of soil moisture is reduced, crop yields increased, and pollination is increased. Pollination relies on the insects and bees do not fly when winds are high. This is important in areas like
Calgary, Alberta where statistics show that the wind blows. Even your home benefits from a windbreak. With reduced wind velocity, heat loss is reduced and therefore the cost of heating is reduced. Birds and animals find shelter and food in the trees and shrubs of the windbreak.
When clearing land, even an acreage, always attempt to leave a natural windbreak of trees to the north and west of home and garden. If none exists, plan for one. If the property is too small, or while waiting for a new windbreak to become an effective size, consider the use of open type fences, such as picket, woven, or snow fences. Do not use solid fences as these do not reduce the wind velocity but can actually increase it. Remember that it takes at least 10 years for a newly planted windbreak or shelterbelt to have any affect.
There are many publications available through the different Provincial Department of Agricultures on windbreaks and shelterbelts. Generally, they suggest that the main shelterbelt should be 6 rows deep. The windward row should be fast growing shrubs, then a row of ornamental trees, a row of long-lived deciduous trees, a row of fast growing deciduous trees and lastly, two rows of long lived conifers. Intermediate shelterbelts can consist of from 1 row of fast growing shrubs to up to 3 rows with fast growing shrubs, fast growing deciduous trees and long lived conifers.
Some of the trees and shrubs recommended for shelterbelts are: poplar, willow, maple, elm, ash, spruce, pine, larch, caragana, lilac, honeysuckle, hawthorn, chokecherry and dogwood. This material is used along with ornamental trees hardy for your zone.
ENSURING A GOOD CROP
There are several factors that affect the growth and maturity of a crop. Heat is one of the main ones. The minimum temperature for growth is 41°F (5°C). If the air and soil temperature can be raised, this will provide more heat units for the crop, and more growth. Excess heat, though, is detrimental to some crops. Peas do not like a temperature over 80.6°F (27°C) and should be planted so that they mature before the heat of summer. Potatoes set tubers better when night temperatures are 50-57°F (10-14°C).
Soil fertility is important for crop maturation as well. Low fertility results in slow growth. Excess nitrogen causes too much vegetative growth and delays maturity. High phosphorus hastens maturity.
Plant population also has an affect on crop maturity. A low plant population matures slightly earlier than a denser population. Plants requiring a long season are best spaced to the maximum distance recommended; while, with short season crops such as radishes, the minimum can be used.
Soil type plays its part too. Sandy soils warm up sooner in the spring but cool off faster in the fall. Clay is just the opposite. So it is seen that a good humusy soil will give a longer season of growth. But too much raw organic matter results in frost retention for a longer period in the spring. Any organic matter added to the garden in the fall should be well rotted.
Soil temperature is as important, if not more so, than air temperature. It affects the germination of the seeds. Plants can survive at lower air temperatures if the soil temperature is kept to the proper level.
Soil moisture must be present at seeding time or germination and therefore growth will be delayed. If snowfall or spring rainfall is scanty, avoid working the soil too much before planting. Just keep the surface worked to provide a mulch to prevent evaporation.
Photoperiodism is another factor governing the growth of plants. Longer periods of daylight reduce the amount of heat required to mature the crop. This is one place where the north has the edge over the south. Spring and summer days are very, very long. At Fairbanks, Alaska, from May 24 to August 30, the hours of sunlight and twilight each day equals 24 hours. Twilight has sufficient light intensity to affect photoperiodic responses and probably some photosynthetic activity. These long hours of daylight give Fairbanks a potential of 430 hours more sunlight than Chicago or the equivalent to 36 twelve-hour days. With the proper selection of cultivars and techniques to improve soil and air temperatures, the yield of vegetables in Alaska greatly exceeds the U.S. national average yield and even the yields of some of the best producing areas of the U.S. This dramatically shows the benefits of northern production of cool weather crops. But some crops cannot tolerate the rapid growth under the long hours of sunlight. Beets and spinach varieties tended to bolt to seed rather than form marketable plants. They found that planting in cold soil increased this bolting tendency. Cultivars should be chosen that avoid this tendency. Boltardy beets and Marathon spinach are two cultivars that do not have this problem.
Pollination is also essential for many crops. To ensure pollination growers often situate beehives in or near the crop or orchard. In the north pollination is often hit or miss in the home garden. Even when the proper cultivars are present for cross pollination, when required, poor crops may still result. Bees will not fly in high winds and in areas like Beaverlodge, Alberta where the winds blow 85% of the time, this can be a serious problem. Windbreaks are necessary to reduce the wind velocity in the garden or orchard. This subject was discussed earlier. Bees are often hindered by cool, wet weather in the spring. To increase the chances of pollination in the orchard, top-work a few branches of a desired cultivar onto your trees. When growing plants in the greenhouse or when using devices such as the Tomato Hoods, insects are usually not able to pollinate the plants. Pollination must be accomplished by other means. Gently shaking the plants, or using a small brush to transfer pollen are two methods to overcome this problem. The fruit of the tomato plant will often be misshapen if poor pollination results. This can also be caused by other factors such as stress from cool temperatures, excess heat, disease, lack of nutrients and drought.
With the short northern growing season, plant material benefits greatly if competition and stress is reduced. This means controlling weeds and insects, as well as providing the nutrients and moisture required by the plants.
HARDY TREE AND BUSH FRUITS
One key to the survival of fruits in the north is the right
choice of rootstocks. For apples, the following rootstocks are used in colder
Budagovski 9-originally developed as a dwarfing stock for the
mountains of Poland-not hardy enough byitself-best used as an interstem on
`Beautiful Arcade' on which it will produce about a 45% tree.
Beautiful Arcade-originally a Russian tree-fruit is edible-comes
true from seed-easy to grow-produces a semi-standard tree (65%).
Baccata-seedling from a wild Siberian crab-extremely
hardy-probably the best for zone 2 and colder. 80-90% tree.
Antonovka-hardy Russian rootstock-in use nearly 500 years-edible
fruit-comes true from seed-90% tree-quite hardy-tolerates clay soil.
Dolga-intermediate in hardiness between Antonovka and Baccata-good
crab apple in itself-makes a 100% tree.
For hardy pears, the choice of rootstock is limited.
Pyrus ussuriensis (Siberian Pear)-extremely cold hardy-zone
1b-sensitive to excess soil moisture-makes a tall, beautiful tree in
itself-attractive to wildlife and makes an excellent windbreak tree.
Cotoneaster acutifolia (Peking Cotoneaster) -currently under
trial-very hardy-zone 2-dwarfing for pears.
Amelanchier (Saskatoon)-zone 2-promotes earlier bearing than
Quince-poor anchorage so trees need support-best used for trellised plantations.
Crataegus (Hawthorn)-very hardy-very dwarfing -unfortunately
graft is unstable and scion dies in about 5 years.
For cherries, the Chokecherry and Pincherry are used as
Prunus virginiana (Chokecherry)-readily available in the
wild-extremely hardy-one of the best possible rootstocks.
Prunus pensylvanica (Pincherry)-wild cherry-less common than P.
virginiana-very hardy rootstock.
Plums can be grafted onto Prunus nigra or P. americana in very
Prunus americana makes a weak combination and the tree should
be planted deep so the scion will develop its own roots.
Some of the cherries such as Prunus tomentosa (Nanking Cherry)
may provide serviceable rootstocks in cold areas.
B. HARDY APPLES
Much research has been done on hardy apples over the years. The
recent release of the Nor group of apples has broadened the selection for home
orchard. In zone 1, Norhey apple, Early Yellow, Osman and Red Siberian Crabs are
being grown. In zone 2, there are several apples, apple-crab and crabs available
but the Noran ranks very high among them. It is a good cropper, keeps well and
is the most blemish free apple at Beaverlodge, Alta. Norda, Norland, Norson and
Patterson are some of the other good apples available for the north.
C. HARDY PEARS
Although there are a few hardy pears available, the quality of
the fruit still needs great improvement. Olia, Pioneer 3, John, Peter, Tait
Dropmore, Tiona and Ure are all hardy but their fruit is of cooking quality
only. More research needs to be done to improve the fruit.
D. SANDCHERRIES AND BUSH CHERRIES
There are many hardy Sandcherries and Bushcherries. Hans and
Fritz are considered the hardiest and tastiest of the Sandcherries. The bush
cherries include Prunus tomentosa (Nanking cherry), P. fruticosa (Manchurian
Cherry), as well as the cherry-plum crosses which include Opata and Sapa.
E. HARDY PLUMS
Plums are grouped by families: European, Damson, Japanese, Native
and American Hybrids. It is essential to know the family groupings when
selecting plums because plums are generally self-fertile. In addition, there are
several family groupings that are cross sterile due to a differing number of
chromosomes. Therefore you must plant 2 different varieties from the same family
group, i.e. 2 different Japanese plums, for proper pollination. The hardy plums
according to family are:
There is a limited number of hardy Apricots for the north. Prairie Gold is not definitely hardy. Sunrise has borne fruit reliably for 30 years at Saskatoon, Saskatchewan (zone 2b) and is worth a try in zone 1b. I have been unable to obtain data on Scout and Brookcot apricots, and so am unable to comment on these at this time.
Strawberries in the north generally require a mulch in winter, although many people such as myself have been growing them for years with no protection. I have grown Chief Bemidji, Autumn Beauty, Protem, and Fort Laramie, all with no mulch. Even when the snow cover is eliminated by
Chinooks, I have had very few losses.
Raspberries are the most satisfactory fruit as they bloom late and therefore escape the late spring frosts. In zone 2b, no protection is normally required for red raspberries but in zone 1, the tips should be covered in winter as recommended for black raspberries. With raspberries, it has been found that those cultivars that experience early leaf drop and a greater reduction in growth after the end of August, tend to be the hardiest. The winter of 1984-85, played havoc with raspberries in the Beaverlodge area. An extremely early killing frost caught the raspberries in full foliage and they were killed back to the ground.
Grapes have been grown in zone 2 but they require special handling. They are trained to a fan shape so that the canes can be laid down and covered for the winter. The native grape, Vitis riparia, has small blue fruit suitable for jelly. Beta has fruit of fair to good quality for juice and jelly but is too acid to make good wine.
J. CURRANTS AND GOOSEBERRIES
Currants and Gooseberries are hardy even in zone 1b with very few exceptions. Some have been grown as far north as the Arctic Circle in favoured sites. Because of their high vitamin content and good flavour, they shoud be planted more extensively.
Lowbush blueberry, Vaccinium angustifolium, requires an acid soil. They are difficult to transplant from the wild as their roots are very thin and dry out quickly. Highbush Blueberry is too tender for the north.
Saskatoons are a native fruit that is presently being developed as a commercial crop in Northern Alberta. The varieties available are selections from the wild Saskatoon. Quite often nurseries will offer seedlings of these selections but seedlings are not always true to type and if a uniform plantation is desired, it is best to obtain root sprouts or grafted material. Named varieties include: Forestburg, Honeywood, Pembina, Smokey and Thiessen.
M. ROSE HIPS
Rose hips are another wild fruit that is used widely for syrups, jellies and eaten fresh. They have a high vitamin C content.
N. WILD CRANBERRY
Highland Cranberry or Lingonberry, Vaccinium vitis-idaea, is presently being developed as a commercial crop in Alaska. Some people prefer the taste of them to the commercial cranberry.
Elderberry, (Sambucus canadensis); Pincherry, (Prunus pensylvanica); Chokecherry, (Prunus virginiana); Sandcherry; Hawthorns, (Crataegus); American Mt. Ash, (Sorbus americana); Highbush Cranbery, (Viburnum trilobum); Nannyberry, (Viburnum lentago); Staghorn Sumac, (Rhus typhina); are all native plants that have an edible fruit.
There is no lack of small fruit for the northern garden. The home gardener has a wide choice of hardy fruit to choose from for his home orchard. The potential for developing a fruit industry in the north is excellent. Specialty jams and jellies have a market.
Content provided by Patricia Chenier Smith
SELECTION OF MATERIAL
This will often be the most difficult part of any horticultural endeavour in the north. Plant material must be chosen in relation to the site, climatic conditions, desired effect, and eventual size of the material, among other criteria.
A. USE OF ZONES
The Calgary area is designated Plant
Hardiness zone 3B
by the USDA (United States Department of Agriculture). The average annual
minimum temperature is -34.5 to -37.2 degrees Celsius (-35 to -30 Fahrenheit).
To help you select the proper varieties for your area, many people have devised systems of indicating zones based on climatic factors. Everybody, it seems, has their own idea of how to represent and allocate these zones. Different government authorities have devised their own zone maps. Horticultural authors, not satisfied with these, often devise their own system. To show how mixed up the present systems become, Beaverlodge, Alberta is in zone 2b on the Agriculture Canada map of plant hardiness zones; and 5b on the Alberta Agriculture map, devised by the W.C.S.H. This means that you must keep track of what system the catalogue or book is using when it mentions the recommended zones and translate this to suit the system you are using.
In 1967, the federal government collected meteorlogical data from 108 stations across Canada. This data included the winter low temperatures, the frost free periods, summer and winter rainfall, summer high temperatures, snow depth and wind speed. A complex formula was used to obtain a numerical value for each area. Based on these numerical values, the stations were designated as being in a zone ranging from 0 to 9, which were further subdivided into A and B groupings. A map was drawn up to indicate the approximate extent of these zones and is available from Agriculture Canada.
The Prairie Provinces have another system of zones. In 1953, the Western Canadian Society for Horticulture published a zone map for the prairies based on the length of the growing season, average precipitation and the temperature range. This map is used in the Alberta Horticultural guide which is available through Alberta Agriculture. The zones on this map do not relate to the federal map in any way at all.
The zone map used by the U.S. Department of Agriculture covers a portion of Canada and is used in most American publications. Because Alaska was not included in the zone map, Alan C. Epps, Natural Resources and Land Use Planning Specialist with the University of Alaska, devised his own zone map based on the same criteria. His system is used in many publications for Alaska.
Some of the Atlantic Provinces have also devised their own zone map for their area.
Now, to add to the confusion, many nurseries do not use any zone system to aid their customers in their selections. Some, such as McFayden, invent their own system to confuse the buyer even more. Those catalogues, such as Sheridan Nurseries, who do include the Agriculture Canada zone map, do not print the entire map. They tend to think that the north is unsuitable for growing plant material and omit this area to save space in their publication. They do not realize that the northwest area of Alberta and British Columbia are farming areas and quite suitable for a wide variety of plant material. This area includes the cities of Grande Prairie, Fort St. John, and Prince Rupert, as well as their surrounding towns and villages. This is a fairly large population of potential buyers that most publications overlook. Note: part of this problem has changed since this was written.
One problem arises when selecting plant material using the zones. Many people feel, because of inherent genes, that if one plant of a specific specie or cultivar survives in a zone area, that all plants of that same specie or cultivar will also survive. In St. Paul, Minnesota, in tests using Cornus stolonifera (Red Osier Dogwood) it was shown that this was not true. These dogwoods were collected from widespread locations in North America and grown in one location in St. Paul. All became hardy enough to withstand the winter temperatures, eventually, but plants native to milder climates were often partially killed back by the fall and winter frosts. They did not acclimatize soon or fast enough. Thus it can be shown that if the plant material is propagated in a climatic area similar to that of the purchaser, it will have a better chance to acclimatize and suffer less kill back. This may not be important for shrubs, but for trees, the damage could permanently mar the natural form of the plant. One should always attempt to select plant material from a source with a similar climate, if possible. Often, though, you have no choice as local nurseries do not always propagate their own stock but buy it from a wholesale nursery located in a more favourable zone. If more northern nurseries began propagating a wider variety of plant material, this problem would be overcome.
B. USE OF BOTANICAL NAMES
Another aid to the selection of plant material is through the use of the botanical names of the plants. There is no standard in regards to the common name of a plant. There are several plants that go by the same common name. The Flowering Plum is a good example. Prunus triloba and Prunus triloba 'Multiplex' are two plants listed as Flowering Plums in the catalogues. They are both hardy in zone 2. Prunus glandulosa and P.G. 'Sinensis' are two flowering plums hardy in zone 5. Without the botanical name, the customer does not know which to buy for his zone.
C. USING GARDENING BOOKS AND PUBLICATIONS
When selecting plants for the landscape or orchard, many people turn to gardening magazines and encyclopedias. Most of these were written with the American market in mind. Even those written for Canada only briefly touch on the northern areas and their specific problems. There was considerable literature put out by Agriculture Canada on the north in the past but most of this literature is either no longer in print or mentions varieties that are not available today. Many times it is impossible to obtain information regarding specific problems of the north. Government publications should be updated and reissued to provide the northern gardener with the information he requires. Some excellent books have been written by people who live and garden in the north, but they do not have a wide distribution. Much of the data in them was obtained from both government research and personal experience. A listing of some of the publications will be included in the Appendix.
D. USE OF NORTHERN VARIETIES AND CULTIVARS
There are many vegetables developed for northern conditions. From Alberta came the Sub Arctic series of tomatoes, Limelight beans, and Earligold melons. From Manitoba came the Prairie Pride and Ping Pong tomatoes, Harper Hybrid melon, Early Arctic corn, Morden Early cucumber, Supersweet peas, as well as the Pee Wee, Little League, Junior and Morden Midget cabbages. A cooperative program between the provinces resulted in the Starfire tomato and the Far North melon. From Alaska came the Alaska Frostless and Alaska Red potatoes. These two potatoes have frost resistent tops and deep tuberization that requires no hilling. A problem in the north caused by the extra long daylight hours has been the bolting of spinach and beets. Boltardy beets and Marathon spinach are not subject to this premature seed production.
There has been much research to develop hardier cultivars of trees, shrubs and flowers for the landscape, as well as hardy fruit trees for the orchard. The list of these is too extensive to include but include many plants developed or selected at Morden, Manitoba; Brooks, Alberta; and Ottawa, Ontario.
E. USE OF EARLY MATURING SEED VARIETIES
When selecting seeds for the garden, one has a slight advantage over the landscaper. Many catalogues list the days to maturity of the different varieties. This gives an approximate idea of the length of time required to mature this particular variety but this can be varied by several other factors, including the length of day. By comparing the different varieties with one you already grow, you can get a fairly accurate picture of whether your season is long enough to grow the others. A more accurate way of measuring time to maturity is using Growing Degree Days. This is the number of heat units or growing degree days and is based on the fact that plants must have a certain amount of heat to make any growth. Sunlight alone cannot ensure growth and therefore maturity of the plant. Most cool season plants require more than 42°F (5.6°C) to grow. This figure is used as a base and is subtracted from the mean temperature for the day to give the growing degree days. The amount of growing degree days (Heat Maturity Constant or HMC) is not available for all varieties as yet but will provide a guideline in selecting varieties when the data is known. An accumulation of 1,000 growing degree days is considered the basic necessity for dependable production of frost hardy vegetables. An example of the benefit of knowing and using the HMC can be shown easily. Ottawa Ontario has only 138 frost free days but more than 2,000 growing degree days. Sidney B.C., on the other hand, has 230 frost free days but only 1,900 degree days. This accounts for why sun loving plants such as corn prefer Ottawa despite the shorter season.
F. CHOOSING PLANTS IN REGARDS TO THEIR CULTURAL NEEDS
Plant material for the north should be chosen carefully. Plants that are very tolerant of adverse conditions will survive well but many plants have explicit needs in regards to exposure, soil type and pH, water requirements, and winter protection. Plants must be chosen taking into consideration all factors of the site, the type of care you will be able to provide them, the desired effect, the cost of providing for their requirements, etc. Some plants, such as cherries, are very susceptible to sunscald and other winter damage caused by exposure to the harsh winter sun and reflection of the sun off the snow. These plants must be given extra protection in the form of wraps, screens, or by planting on the north or east side of a shelter. Other trees need shelter from the north and west winds. It is no use planting material that requires winter protection if you have no intention to provide it. You will be throwing your money away. Do not choose a plant just because your neighbour grows one. By using references, you will find just the right plant for your needs. A flowering cherry may not be hardy in your area, but there are many flowering crabs that rival the spring beauty of the cherry.
G. THE USE OF NATIVE MATERIALS IN CALGARY
In zones 1 and 0, quite often the only plant material available is native plants. Native trees and shrubs will make good landscape material if moved when young and given proper training and care. Judicious pruning and fertilization can improve the appearance of a wild tree considerably. Some "imported" material will survive in these extreme northern areas. For instance, in Yellowknife (zone 0), Prunus padus (Mayday Tree), Flowering Crabs, Mountainash, and Weeping Birch have been grown successfully. Shrubs such as Ural False Spirea, Potentilla, Cotoneaster, Caragana, Lilacs and Mockorange have been grown in zone 0, when given reasonable care.
ROSES FOR THE NORTH
When purchasing roses for the north you should be aware that roses have varying degrees of hardiness. Hybrid Teas, Floribundas, Grandifloras and Climbers are all tender roses and in the north will usually require extensive protection to survive. Half hardy roses include the Hybrid Perpetual, Miniatures, and Polyanthas. The hardy roses are the shrub roses and these require no protection in the north. The Brownell sub-zero roses are not fully hardy on the Prairies.
Try to obtain your rose bushes from a nursery that does not trim off too much of the root system. Those fancy boxes of rose plants available in the local department store or supermarket have had their root systems butchered to fit the box. Roses are heavy feeders but have poor root systems. They require as much of the root left intact as possible if they are to survive more than one season.
There are many hardy shrub roses available today. The list is too extensive to include but some of the newer cultivars are:
There is very little difference in the care of roses whether in the north or south. The main difference is in the timing of the operations. In the southern part of the prairies, roses are mounded about the 3rd week of October. In the northern areas, by mid-October. The straw should not go on until after freeze-up to prevent rodent damage. This is usually in November but the material should be available sooner in case of early freeze-up.
Roses grafted onto Dogrose rootstock (Rosa canina) are preferred for the prairies as this rootstock has a deep penetrating root system. This enables the rose to withstand drought better. Roses on this rootstock also tend to ripen their wood earlier and this gives them a better chance of survival over winter. The only drawback to this rootstock is that it has a poor fibrous root system and is difficult to transplant.
I will not get into the regular care of roses but I wish to discuss a special technique used by an Edmonton rose grower with great success.
Mr. G.W. Shewchuk of Edmonton, Alberta (zone 3a) has grown hundreds of tender roses yearly with very little losses. He has developed his own technique for planting. He plants his roses with the graft union 4" (10cm) below the surface of the ground. Because of the depth used, the plant is placed on a slant to ensure that the roots are not buried too deep. When backfilling the hole, he does not place soil over the graft area. Instead he uses a coarse aggregate such as sand, perlite or vermiculite over the graft. This is done to permit the new growth to emerge more easily. He leaves a saucer for watering so in reality the graft is only 2" (5cm) below the surface. At first the old branches will be at an angle but the new growth will be upright. He still mounds his roses for winter but not as deeply as usually recommended. With his method, he lost only 7 out of 300 roses in 1979 and only 5 out of 315 in 1980. Most of the bushes he lost were older bushes and may have died simply of old age. He has some which are over 14 years old. His experience has shown that northerners do not have to envy their southern neighbours. They, too, can have beautiful rose gardens.
INCREASING WINTER HARDINESS
To ensure the successful wintering of permanent plants such as perennials, fruit trees, turf grasses etc. the secret is to have them face winter in a hardened condition. They must be as close to dormancy as possible and fully matured. To assist them to reach this condition, cease the use of fertilizer by mid-summer, generally. For turf, use low nitrogen fertilizers in the fall. Any fertilization of trees should be a with low nitrogen fertilizer and only after leaf drop to prevent the growth of soft succulent tissue which would not have time to harden off. In wet areas, cease cultivation by the end of July to aid the hardening process. Water only sparingly from August to October but ensure the plants receive sufficient water before freeze-up.
A. IN THE ORCHARD
In the orchard, planting a cover crop such as fall rye or oats in late July serves three purposes. The cover crop absorbs nutrients and moisture, slowing down the growth rate and aiding the trees to harden off. The cover crop also traps snow and holds it so that it will provide moisture when spring thaws occur. Grass has also been used successfully for this purpose but it must be mowed short to discourage rodents which will attack the trees during winter doing extensive damage and often killing them.
Overbearing of fruit trees leave them weakened and susceptible to winter damage. Always thin fruit crops when young. This ensures an even distribution of fruit over the tree to reduce the weakening of branches from overweight. Delay thinning the fruit until after natural fruit fall of apples in early June. Blossom thinning chemicals are not advised on the prairies. Late spring frosts may kill blossoms at any time and if coupled with chemical spraying, very few fruit will survive.
Another way of increasing the hardiness of fruit trees is by the use of stem builders. The main trunk and branches of a fruit tree are the most susceptible to frost damage. Stem building is the process of budding the desirable apple onto the frame of a very hardy crabapple. This makes a sturdier, hardier tree. If Malus baccata is used for the frame, a dwarf, low-headed tree will result. In Russia, apple trees are trained to stay close to the ground to take advantage of snow cover. Good crops have been reported using this method. In Quebec, orchardmen are starting to use a method called Swiss pruning to keep trees low for ease of spraying and picking. It is used to rejuvenate standard apple trees which have grown too tall. I have not been able to determine if the Russian method and the Swiss method are the same but the descriptions are very similar. It is a method of training apples that should be looked at for the north.
Roses are considered too tender to over-winter in the north but this has been proven wrong many times. The key to survival of roses is similar to other plants. Cease fertilization in July. When cutting roses late in August and onward into the fall, always cut with a short stem to avoid stimulating new soft growth. Some growers recommend removing the foliage from the lower half of the bush in late August to slow growth. Reduce watering beginning September but do not allow the rose bushes to become dry. These procedures will help the roses harden off properly for winter.
CALGARY FROST PROTECTION AND CONTROL
As well as the many other methods of aiding plants to survive in the north already mentioned, such as proper site selection and row covers, there are many other methods to help prevent early frost damage and extend the growing season. The first thing you should know is the temperature. That outdoor thermometer hanging by your window does not give you a clear picture of the temperature. The temperature that is used by the weatherman was obtained from a thermometer in a shelter at about 4 1/2' above the ground. But on calm nights, the minimum temperature at ground level is often 1.8 to 10.8°F (1 to 6°C) colder than this. This is significant because most frost damage occurs during clear calm nights.
After you have chosen your site and prepared it well, you can use another trick to help your plants. Site the plants in relation to their cold hardiness. Place the tender plants upslope where the danger of frost is the least. Avoid the low spots where the downflow of cold air might be hindered.
When Calagry frosts become imminent, managing the soil can provide an extended period free from frost. The idea is to use the heat stored in the soil to warm the air around the plants. This is readily achieved when the soil is bare, moist, packed, and not too rich in organic matter. All organic matter added late in the season prior to harvest should be well rotted and well worked in. Avoid loosening the soil which would lower the temperature of the soil surface by 1.8 to 5.4°F (1 to 3°C). Time tillage operations, hilling of plants etc. based on the weather reports. Packing loose soil, or watering it to consolidate it, will improve its heat retention and increase the availability of soil heat on cold nights. Weeds should be minimized and the use of ground covers and mulches avoided in the garden at this time. Note that this contradicts the procedure used in orchards but in this case we are trying to keep active growth going for a longer period of time.
Another way to extend the growing season is to use heaters or open fires to counteract the heat losses. A large number of small heaters is better than a few large ones. Needless to say, this method is for valuable crops only.
If crop shelters, as mentioned earlier for spring frost control, are used, often plants can be protected from the early frosts and another few weeks of growth can be accomplished.
Another method that has been tried, is using fans to mix the air near the ground with the warmer air above to moderate the temperature.
Sprinkling the plants with a fine mist of water will protect them down to 19°F (-7.2°C). The water should be applied at 1.2" per hour beginning when the temperature drops to 32°F (0°C) and turned off when the temperature returns to above freezing. The thin layer of ice that forms protects the plant by acting as insulation. It will often get the crops through the first few frosts and therefore extend the season, increase the yield and even double the yield in some instances.
Many people tend to feel that the only trees that will grow in the north are Poplar, Willow, Birch, Spruce, and Creeping Junipers. If the zones were included in catalogues, they would soon realize the wide variety of hardy material that is available. Even in zone 0, Prunus padus commutata (Mayday Tree), Flowering Crabs, Sorbus (Mountain Ash), and Betula pendula gracilis (cutleaf Weeping Birch) have been grown successfully. The list of trees and shrubs for the remaining zones would be too extensive to list but include a few not often seen in the north. Aesculus glabra (Ohio Buckeye) and Celtis occidentalis (Common Hackberry) are two excellent trees that should be grown more often. Juglans nigra (Black Walnut), Quercus coccinea (Scarlet Oak) and Juniperus chinensis `Ames' are three trees that have been proven to be hardier than previously thought through the work of the W.C.S.H. Trees like Poplar, Willow, and Manitoba Maple are best used for windbreaks where their quick growth is an advantage and their greedy roots will not be competing with the landscape material or damaging the sewer systems.
LAWN AND TURF
In Calgary, a lush green lawn can often be a liability. A lawn that remains green up to freeze-up is not properly hardened off for winter and will be susceptible to winter damage. Merion Bluegrass is a cultivar that tends to stay lush too long and should be avoided in northern lawns. Merion is also subject to cold injury and numerous diseases. Choose you grass seed mixture according to the care and use your lawn will receive. If you can provide irrigation, Kentucky Bluegrass cultivars such as Nugget, Banff, Dormie and Park are recommended. They are hardy and resistent to snow mold. For shady areas use Dawson or Boreal Fescue. For dry areas where irrigation is not possible, use deep rooted and drought tolerant grasses such as Crested Wheatgrass (Agropyron cristatum) or Russian Wild Ryegrass (Elymus junceus). The cultivar of Crested Wheatgrass that is recommended is `Fairway'. The recommended cultivars of Russian Wild Ryegrass are `Sawki', `Mayak', `Swift', `Cabree'.
Many of the diseases of turf grasses common to moister and warmer climates are rarely a problem in the north, but those that do occur occasionally become severe enough to cause extensive damage to the turf. There are many publications on diseases and insects of the lawn, so I will not discuss that here.
The main cause of winterkill in the northern lawn is physical damage. This is caused by foot traffic, snowmobiles, cars etc. Always keep traffic off the turf. Avoid building skating rinks on turf areas unless you are willing to accept any winter kill that results. It only takes one pass of a snowmobile to pack the snow down and reduce its insulation value. It is the insulation provided by the snow that enables most plants to survive the winter.
GROUND COVERS IN CALGARY
Ground covers are used where grass will not grow or would be impossible to mow, to provide a unifying effect to the landscape, to reduce weed problems, among other reasons. The main prerequisite for a ground cover is that it be capable of providing the desired effect in two growing seasons. Ground covers range from perennials of a few inches in height to shrubs of several feet. Many ground covers that become weed problems in the south can be safely used in the north where little else will survive. In zone 0, Creeping Charlie (Glechoma hederacea) is used for a ground cover. Other hardy ground covers include: Arctostaphylos uva-ursi, Aegopodium podograria variegata, Vinca herbacea, cerastium tomentosa, Dianthus deltoide, Phlox borealis, Thymus serphyllum, and the creeping and common Junipers. Vinca minor is usually not considered hardy enough for the north, but I have grown it for over 10 years in zone 2b with no winter kill and very little damage. The first site is on the west side of a mobile home where the plants are exposed to the south-west sun in winter but protected from the summer sun by deciduous shrubs and rarely have snow cover due to the sun reflected off the metal covering of the home. The second site is to the north of this same home where snow cover is often melted by the heat of a dryer exhaust. In both locations the Periwinkle thrives despite the adverse conditions.
CALGARY TURF GRASSES
Even with turf grasses, the key to success is ensuring that the grass plants are as close to dormancy as possible when they go into winter. Again, fertilization plays an important part, along with the amount of soil moisture, mowing height, amount of thatch, presence of snow cover, and the cultivar selected. Do not use cultivars that remain green and succulent for they will be too susceptible to damage. Merion Bluegrass is the worst cultivar for this problem. Even though a lush green lawn is considered a status symbol, it is a liability in the north. Dormie is the earliest cultivar to go dormant and is the one most suitable for the north. When irrigating turf, always water deeply and ensure that the turf is watered well in the fall. Improve surface drainage to eliminate pockets of standing water which will damage the lawn. To ensure that the soil will retain sufficient water to overcome the dessication of the sun in early spring, dethatch, core and/or aerify the lawn at the appropriate time. Fall seeding is sometimes recommended for a lawn but it is important that seeding be done early enough that the grass plants will be mature and hardened off before the severe winter weather sets in. Most important of all is KEEP TRAFFIC OFF THE TURF in winter. This includes foot traffic, snowmobiles, anything that compacts the snow surface reducing its insulation value. More damage is done by this one factor alone than all the others combined. Always mow as required until dormancy is reached. Cut higher in the fall to provide insulation but excess height will result in the grass plants smothering. Damage caused by factors such as snow mold can be minimized by keeping the lawn healthy and by the use of fungicides in the fall.
CALGARY ROCK GARDENS
Rock gardens can
be grown very successfully in the north. The climate is more suitable to
the alpine plants often used in the rock garden. Alpine plants are
conditioned to intense light, dry air, long winters and sudden changes
in climate. Snow cover is essential, though, and evergreen boughs should
be placed over the plants to help trap the snow.
Rock gardens should only be established where they will look
natural. Use rock native to the site for the proper effect.
When given a well
prepared site and some winter protection, most perennials will thrive in
the north. The secret is to protect them from the freeze-thaw cycles
with a mulch or adequate snow cover. Peonies, lilies, Maltese Cross,
Delphinium, and Shasta Daisy do not require any protection, even in the
north. Anemones, Arabis, and Astilbe are not recommended for the north.
Even in zone 0, perennials provide some welcome color to the landscape.
At Yellowknife, N.W.T., most of the common perennials can be grown.
Oriental Poppy is variable in hardiness and it is recommended that it be
grown from seed in the north rather than purchased as plants which may
not be hardy. This will reduce to cost to the grower. The best source of
information on perennials is "Canadian Garden Perennials" by A.R.
Buckley and which is available from Agriculture Canada.
annuals can be grown in the north. Some requiring a longer season are
best started indoors. For a longer season of bloom, select annuals that
will withstand a few degrees of frost. This will ensure that those late
spring frosts will not wipe out all your work and the plants will
survive the first fall frosts to give you color after the more tender
annuals are gone. The annuals that will survive minor frosts are
Alyssum, Snapdragons, Asters, Calendula, Dusty Miller, Nicotiana, Pansy,
Phlox, Schizanthus, Wee Willie, Strawflowers and Petunias. Pansies,
Violas, and even Wee Willies will often survive the winter to give you
an early spring show.
CALGARY CLIMBERS AND TRAILERS
Finding climbers or vines for the north involves a lot of searching through catalogues. Most nurseries carry the tender ones such as Clematis Jackmanni but few carry the hardy ones. Some of the more hardy vines are:
Vitis riparia (Riverbank Grape) indigenous
Parthenocissus quinquefolia (Virginia Creeper)
Celastrus scandens (Bittersweet)
Clematis ligusticifolia (Western Virgin's Bower)
Clematis tangutica (Chinese Clematis)
Clematis serratifolia (Korean Clematis)
C. ligusticifolia X C. serratifolia (Grace Clematis)
Menispermum canadense (Canada Moonseed)
CALGARY BULBS AND TUBERS
Most bulbs can be grown in the colder areas except for Hyacinth, Daffidols and various Narcissi unless they are given extra care. These bulbs are best grown indoors. Most tubers such as Dahlias are very successful in the north. The main difficulty with the early spring bulbs is the planting time. Quite often the weather becomes unsuitable for planting before the bulbs arrive. When planning on planting bulbs in the fall, prepare the ground ahead of time and mulch to prevent freezing.