?> St. Mary’s Nursery & Garden Centre Ltd. » FAQs Winnipeg’s Premier Garden Centre


When is the best time to prune my trees and shrubs?

In general, deciduous trees and shrubs are best pruned when dormant (i.e. Early spring too late fall after the first frost). The exceptions to this rule are lilacs and mockorange that should be pruned after they flower and Maples and Birch trees which should not be pruned in the spring. Evergreen trees and shrubs are best pruned in the beginning of August.

When is the best time to plant?

If you are planting bare-root (i.e. the roots are no longer covered with soil), you best plant first thing in the spring or after the first frost in fall. If your plant is potted, you may plant anytime within the growing season.

When should I be using fertilizer and which type of fertilizer is best for me?

There is no bad time to use fertilizer, only wrong types of fertilizer. Fertilizer formulas are typically indicated by 3 numbers the first on the left indicating level of nitrogen, the centre number indicating level of phosphorous, and the number on the right indicating the potassium content. The numbers may vary in value, but what you are looking for is a similar ratio (i.e. High first number for evergreens, high middle number for rooting and blooming, equal numbers for a general purpose fertilizer, etc.). Always follow the package directions for the specific fertilizer you are using.

For evergreen trees and shrubs we recommend a fertilizer high in nitrogen such as a 30-12-12. For deciduous trees and shrubs you can use a good general-purpose fertilizer such as a 12-36-12. Flowering plants need a fertilizer that is high in phosphorous such as 15-30-15 or an all-purpose fertilizer like a 20-20-20. Some fertilizers are specially formulated for specific plants such as cacti and African violets, come down to our store to see our selection.

Fertilizers come in different forms as well. Liquid fertilizers are absorbed readily into the plant and need to be applied more frequently than a granular fertilizer. Granular fertilizers are typically slow release fertilizers that release their nutrients as water trickles over it. Osmacoat is a very slow release fertilizer that will release its nutrients over an approximate 6 month period. Stakes are another fertilizer application that slowly releases their nutrients, but in higher quantities.

How do I care for my hanging basket of annuals?

Water regularly on hot days, using fertilizer each time you water it. Check frequently to see if the plants require watering. Deadhead the flowers when finished to produce more blooms.

What is the best way to plant a tree or shrub?

Every tree should be planted in accordance with an overall landscape plan that considers the effect to be achieved and the size and maintenance of the plants. For best results you can then follow the following steps. Remember, it is better to plant a $50 tree in a $100 dollar hole than the other way round.

  1. Dig a large planting hole approximately two times the size of the root ball. Rough up the edges of the hole so you do not create a pan condition where water pools around the roots of your freshly planted tree.
  2. Prune any broken branches or roots sparingly. Cut them at a point just above the break. Begin corrective pruning after a full season of growth in the new location. For more information on pruning, we offer courses in the spring on proper pruning technique. See our newsletter for dates.
  3. Prepare the hole and soil. Use rich, well drained soil and a plant start fertilizer that contains Indole 3 butyric acid.
  4. Remove the tree or shrub's container. If the tree is balled and burlapped, cut the string and remove all accessible burlap. For trees in plantable baskets, cut the sides and remove peat rim. When planting trees bare root, spread out the roots in the centre of the hole and mound up the centre of the planting pit.
  5. Plant tree or shrub at the same depth as the plant stood at the nursery (plant 1" deeper in the fall). Always lift a tree by the root ball. Place soil underneath to raise tree to its proper growing level, indicated by a dark stain on the trunk marking the difference between the root and trunk bark. Grafted trees should be set with the graft just at the soil line. Plant Spruce trees 2" higher than surrounding soil level.
  6. Fill the hole with good topsoil mixed with compost, stamp down gently but firmly to hold it in place and eliminate air pockets. Rake a ridge of soil 2 to 4 inches around the hole to serve as a reservoir for watering.
  7. Stake the tree. Trees should be staked to avoid shifting during heavy rains or high winds.
  8. Add a plant start fertilizer as directed.
  9. Mulch the tree base. Apply mulch (tree litter, shredded bark, etc.) to the base of the tree to conserve soil moisture and protect tree roots from temperature extremes.
  10. Water regularly and well. Watering is important to aid development of a strong new root system. Keep soil moist but not soaked. Water generously 3 times a week and fertilize 3 times through the growing season.
How do I improve my soil conditions?

Well-structured soil provides the best foundation for your yard as it allows the roots to breathe and provides the right amount of nutrients and water to the plant. Poor soil with incorrect pH balance and poor structure can inhibit plant growth.

If the clay content is too high, it will compact readily, drain poorly, prevent air from getting to the roots and dry in hard clumps. Soil that is too sandy drains too quickly erodes easily and has difficulty holding nutrients. Good soil is a balance of these extremes. Quality soil should feel moist and loose without falling through your fingers and have a rich dark colour and fresh clean smell. The ideal soil is one so loose and friable that an arm could be thrust into it up to the elbow.

To discover your soil structure, stir a handful into a clear glass of water and let it settle for several hours. The soil particles will settle in layers with fine clay particles on top and coarse sand at the bottom, a layer of silt between them. Organic matter will float on the top and makes up less than 5% of most soils. It should be fairly clear what your soil is comprised of.

If you have sandy soil, the solution is digging in lots of high organic topsoil, peat moss, compost and alfalfa moss. In the case of silty and clay soils, the addition of washed coarse sand, perlite, vermiculite and alfalfa pellets will help it drain and aerate. All soil benefits from liberal applications of compost. Work the soil by turning it over and mixing it to a depth of 8-12 inches.


pH influences the availability of nutrients for the plants in that area. Acidity or Alkalinity is measured in pH values ranging from 1 (acid) to 14 (alkaline) with 7 considered neutral. Adding peat moss or small amount of aluminum sulfate can neutralize alkaline soils. Acidic soils can be neutralized by adding dolomitic limestone. Change pH gradually.

Plants need a good balance of major nutrients (Nitrogen, Phosphorous, and Potash) as well as micronutrients. To identify your soil composition test first for pH then test for nutrient levels, which will be readily available to your plants in a soil of a relatively neutral pH level.

Is St. Mary's Nursery and Garden Centre open year round?

Yes we are open year round. In fact, if you have not been out to see our Christmas store you are missing out. In the fall, the store goes through a transformation from greenhouse to winter wonderland. We have everything you need to deck your halls for the holiday season. Come and check out our Christmas decoration classes, family fun days, and more!

How can I have the best lawn possible?

Every homeowner wants a showpiece lawn, soft, thick, weed-free and green. Begin with a thorough raking to remove as much thatch as possible (a de-thatching rake is very effective). Mix two and a half 3.8 cubic foot bales of peat moss with one 110 litre of vermiculite. This makes a sterile weed-free mixture that will cover approximately 1000 square feet. Spread a layer of this mixture thinly over the lawn.

Apply grass seed at the rate of three pounds per 1000 square feet. Fertilize with 24-5-11fertilizer at the rate of five pounds per 1000 square feet or use an equivalent fertilizer and follow the packages instructions. Using a lawn roller at this point is recommended to ensure that the grass seed is in good contact with the "soil". Water the lawn immediately, and keep it moist until the grass seed has germinated. This should be one week for Rye, two for Fescue, and three for Kentucky bluegrass. A blend of the above grass seed is recommended. The best time to seed grass is early spring or early fall (late August and September).

For an old or compacted lawn use an aerator to core the lawn. Do not remove these plugs, as they will break up on their own. Add two 110 litre bags of perlite to the peat/vermiculite mixture and proceed as above. By using this light, weed free mixture the lawn will become less compact and allow the sub-soil to hold more moisture resulting in less run-off when watering and less maintenance.

Once the lawn's condition is considered acceptable, this mixture can be applied every two or three years to maintain your lawn's vigor.

To keep your lawn in top condition, a 3 step fertilizer program is best. Fertilize in early spring with a 24-5-11 to promote strong, new green growth. Mid-summer, use a liquid weed-n-feed of 15-5-5 if broadleaf weeds are present, if they are not, use a 18-24-12. To help your lawn resist winter stress and green-up quickly in the spring, use a fall fertilizer (12-8-16) in September, if weeds are still a problem us a weed-n-feed 12-8-16. We recommend a fertilizer that contains IBDU, a controlled release pattern that spreads the feeding of nitrogen over a ten to twelve week period. It has a 3.1% Sulphur plus the advantage of other organic elements.

Does St. Mary's Nursery and Garden Centre do yard maintenance?

Unfortunately our range of services does not include landscape maintenance. Please contact one of the many local yard maintenance professionals in your area.

What is wrong with my plant or lawn?

There are a range of issues that can affect the growth and appearance of a plant. To get an accurate assessment of what your particular problem may be and its appropriate solution bring a sample (sealed in a ziplock bag or airtight container) to our store, where our experienced staff can help you. Pictures of the overall lawn or plant may also be helpful.

How do I calculate the amount of liner required for my pond?

To find how much liner you need you simply find the maximum length (x) and width (y) of the pond area and add double the maximum depth of the pond (z).

X + 2Z = Total Length of Liner Required Y + 2Z = Total Width of Liner Required

Keep in mind you will need approximately one foot extra if you are joining liner although it is best to use one seamless piece if possible.

How do I calculate the volume of my pond to ensure I have the correct sized pump?

Multiply the maximum length (l), width (w), and depth (d) of your pond in inches. This will give you the overall volume (V) of your pond. Then divide the volume by 231(US Gallons) to get the Gallons Per Hour (GPH) required for your pond pump.

V = (l w h)/231

At the very minimum, 1/2 of the pond volume should be pumped every hour with mechanical filtration and 1/3 with biological filtration. So look for a pond that will pump the appropriate GPH (Gallons Per Hour).

When is the best time to water?

Remember that if plants do not like the area they are in they can not pick up and move the conditions have to change for them to thrive. The gardener is responsible for watering and maintaining healthy plants.

Generally morning or evening is best the best time to water as those times limit the amount of evaporation. In many cases early morning is optimal for watering as evening waterings can lead to mildew and fungus problems in some conditions.

The amount of water required is determined by the climatic conditions and the area the plants are in. Typically, plants prefer to be moist in a well-drained area. For example, in a wet season or area plants will require less water than in a drought condition where they require more. Remember to soak the plant and surrounding soil thoroughly than to merely wet the surface.

Newly planted container plants will need to be soaked through the root ball into the surrounding soil to ensure they root out properly. After being planted, plants should be checked daily for the first two weeks and two times a week thereafter. Plants can recover from a mild drought or wilt, but not from constantly sitting in wet, poorly drained soil.