The Summer Solstice is June 21, the official start of summer.
It has arrived with a heat wave. Now we’ll be looking for shade.
Shade trees, a valuable part of the landscape, must be chosen with care.
Things to consider:
1) Select tree species for their mature size.
There should be enough space for it to grow to its full glory without running into power lines or clotheslines. Make sure it won’t grow to hide a desirable view.
It should be able to spread without being crowded by other trees or buildings or impinging on sidewalks and roads.
Trees planted in the wrong place may require costly pruning to keep them within space limitations.
Often this destroys the look and the health of the tree and creates a need for ongoing pruning.
2) For summer cooling shade, choose deciduous trees for south and west sides of buildings. Once leaves drop, cheery winter sun can shine through.
Coniferous trees are best used on north or possibly east sides of buildings.
3) Look for maintenance issues that may be problematic.
Is it hardy here? Is it prone to pests and diseases? Does it drop seeds that will become a weed problem?
4) Choose species that have low water needs once established.
For small spaces there are several low-water species that are twenty-five feet or less at maturity.
The Amur Maple and Golden-Rain tree are lovely, small, umbrella-shaped shade trees, growing 20 to 25 feet high and wide.
The Golden-Rain tree has yellow flowers in July and lantern seed pods that are attractive in winter. It requires good drainage so is not suitable for clay soils.
The Japanese tree lilac ‘Ivory Silk’ is a similar shape but only 16 feet wide. In June it has large plumes of creamy flowers.
‘Paul’s Scarlet’ hawthorne has deep pink blooms in May and grows to about 25 feet.
Apricot and Italian plum trees can be trained to form a shape and size similar to the Amur Maple. Both are drought-tolerant once established and produce well without needing any pesticide sprays.
Drought tolerant shrubs that can be trained into a small tree shape include smoke bush (Cotinus coggygria ‘Royal Purple’), Rose of Sharon, ‘Diabolo’ ninebark and beauty bush (Kolkwitzia).
Small native trees are Douglas maple and Columbia hawthorne.
For information on these and other drought tolerant trees, go to the plant database at www.okanaganxeriscape.org
It’s best to plant in early spring or fall.
Soak the planting hole; allow to drain; make sure the tree root ball is soaked through; loosen roots; soak after planting; create a ring of mulch around the tree (keep away from the trunk); soak the mulch layer.
Trees need regular watering for the first few years until they have a good root system. A Treegator bag can be used to slowly irrigate.
If hand watering, create a well around the tree so that it can be filled to provide a deep soak.
Gwen Steele is executive-director of the non-profit Okanagan Xeriscape Association.