Tree & Shrub Care

At greengate, we are dedicated to helping not only providing you the best trees & shrubs in Calgary, but also providing you the expert knowledge to help you care for your trees or shrubs.

It is not difficult and if done correctly, your greengate trees will grow healthy and strong!

Here are our tips:

(Learn even more when you come in to greengate and talk to one of our tree experts.)


In dry climates like Calgary, water is one of the most important things we can give trees, shrubs and evergreens. Deep water on a regular basis throughout the season - especially during dry spells. Lay your soaker hose around the drip line of the tree (where water runs off the tree and on to the ground) and run slowly for several hours. Avoid frequent shallow watering as it encourages shallow root growth. It is best to water deeply and slowly, which will allow the water to reach deeper roots and be retained by the soil longer.

Water freshly planted trees and shrubs thoroughly to give them a good start. Thereafter water when the soil surface dries out. It is best to water deeply and slowly, which will allow the water to reach deeper roots and be retained by the soil longer. Using a soaker hose around the base of trees and shrubs is usually the most effective way to ensure deep, thorough watering. Do not rely on rain to water your trees and shrubs sufficiently.

It is important to observe the condition of your trees and shrubs often to ensure continued healthy.

All trees should be well watered in the fall as a routine practice, with special attention to those showing any drought symptoms.

Post-planting care

For the first season newly planted trees and shrubs should fertilized using a fertilizer with a high phosphorous content, with is the middle number, we recommend 10-52-10, which stimulates root growth.

Note: If Myke has been used when planting the tree or shrub, Myke's fertilizer must also be used since its low ratio of elements will not inhibit Myke's production of root extensions (filaments) provided by mycorrhizae. Trees and shrubs planted using Myke carry an extra 5 year warranty if the terms and conditions of the Myke Tree and Shrub Warranty are followed.

For established plants you can fertilize deciduous trees and shrubs every two to three weeks, until August 15, with an all-purpose, water soluble fertilizer such as a 20-20-20. For evergreens a 30-10-10 ratio applied in 3 times during the growing season, in May, June and July, is recommended.


Routine feeding and watering will generally be enough to satisfy the nutritional needs of trees and shrubs through their growing season.

Water trees and shrubs in well by the end of October. Ensure that your plants root-ball is completely saturated by performing a slow, thorough watering.

Trees and shrubs may be pruned back and mulched for extra protection in the fall. This mulch should be removed in the spring. Dead foliage should be pruned away in the spring.

When to Fertilize Trees

The best time to fertilize trees, shrubs and evergreens is just after they leaf out in early spring. One application of a well-balanced fertilizer is all they need. Don't apply any fertilizer after the first week of July depending on your growing season, as trees need time to slow down plant growth and develop buds before fall. The only exception is new transplants, which require a light root fertilizer after planting.

Fall Tree Protection:

If there is a prolonged dry period in the Fall it is important to water your evergreens.

Do not water at the trunk of the evergreen because you do not want the trunk wet if and when it freezes. Water slowly and deliberately before freeze up and watch the weather. There may be periods in the winter and early spring where these trees may need to be watered again.

For winter protection of cedars, we recommend that you create a windbreak at least 6 inches away from the plant. This can be created with burlap and heavy bamboo canes. In some areas, this may not be necessary (i.e. eastern exposures) or microclimates created by varying altitudes, and older neighbourhoods where large trees and houses cut down on exposure to that dry West wind known as a Chinook.

Most evergreens we grow are native here and can cope. Spruce, pine and juniper tolerate our dry climate and strange weather patterns amazingly well. Cedars, however, are native to climates where winter is consistently wet and cool. We can't give them that, and many don't survive our winters. Cedars have more chance of survival in climates that stay cold throughout the winter more. They are one evergreen that should be watered periodically until the ground freezes, but don't overdo it! They have a better chance in a shady spot than in direct sun and winter wind.


Pruning Shrubs

Early spring is the time to tidy up and prune your shrubs. Prune away crossing branches. Each branch needs its own space. However, if they are spring flowering shrubs do not prune until after they flower. e.g. Lilacs or Nanking Cherry.

Remember shrubs planted around your foundation can help maintain winter heat and summer cool.


Birch Leafminer

Birch Tree
Birch Leaf Miner Larvae

When saving your Birch Tree timing is the Key!

In the past, we have been able to purchase a number of different controls for the pest known as Birch Leafminer. Today there are very few, however, nematodes have been found to be very effective at controlling the larvae before they emerge from the ground and now is the time to act.

Birch Leaf Miner Larvae

If you have seen or have had Birch Leafminer in the past, then you know that the damage is unsightly and not really great for the overall health of the tree infected. However, tree death has not been implicated from Birch Leafminer. Damage appears as a small brown or reddish-brown, irregular-shaped patch on the upper surface of the leaf. It actually looks much like a mine through the centre of the leaf. If the mine is occupied, the pupa can be seen when the leaf is held up to a light. The issue is that the pest once inside the leaf is protected from topical treatments.

Leaves that are attacked by Birch Leafminer larvae will often appear curled at the edges. The Leafminer attacks before the leaves have fully expanded, which interferes with normal development and results in a deformed leaf. This is why introducing nematodes into the soil before the tree leafs-out is important! To control the pupa while they are in the soil is most important. Once they are in the leaves or are at large as an adult the nematodes are ineffective! The pupa are now coming out of cocoons where they overwintered from last year. The female will move up the tree depositing eggs that hatch and feed on the leaves before emerging as an adult. Birch Leafminer nematodes attack the pupa in the ground and interrupt their life cycle before they can do damage to the trees. Nematodes are basically microscopic worms that move through the soil by water channels between the soil structure. It's important to apply nematodes at the right time and temperature. Plus 10 degrees is required. Nematodes are applied by mixing them in water or a dispenser designed specifically for the application. Water with the nematodes around the tree's drip line and that's about it. Once the nematodes are in the soil water again in a couple of days, this will help them move about and track down their prey.

You will find the nematodes in the fridge here at greengate Garden Centres and just a tip: keep them refrigerated until use.

Spruce Sawfly

Spruce sawfly larvae are small green, orange headed, caterpillars that damage evergreens by eating new growth. Unchecked they can strip a branch bare. To control them use Diazinon diluted with water. Diazinon is an insecticide that will not harm the tree itself, but kills the insect on contact.

Spray only when the caterpillars appears. If you see continued damage you may need to spray again, ideally 10 to 14 days after initial spraying or after a rainfall.

Remember: Always read the label before use of any pest control product.