The Right Tree in the Right Place

Published in the Toronto Star – April 1, 2017

A new gardening season is ahead of us: a fresh chapter in the book of life-with-nature. I recommend that we make the best of it and plant some trees. It is important to plant the right tree in the right place. Here are some considerations when planting trees and my top recommendations:

1. Small trees that flower and fruit. Small lots and densely populated urban areas are no longer suitable places for large growing shade trees. Here are my favourite trees that will grow no higher than 7 meters and will flower and/or fruit:

Dwarf Apple trees. There are dozens of varieties of dwarf apple trees available. My favourite apple for vigour and strength is Cortland. The tree grows relatively quickly and produces lots of great mid-season eating apples. Otherwise, just look for an apple that you like to eat.
The lowest-maintenance fruit tree out there. No need to look for ‘dwarf’ pears as a standard pear generally grows to about 6 or 7 meters, given enough time.
Sour or sweet cherries grow reliably in Toronto (zone 6) but not so much in Ottawa or Montreal. ‘Stella’ is a great choice for a sweet cherry as no partner is required to cross pollinate, otherwise you will need two. Sour cherries are self-fruitful.
Crab Apple. An unfortunate name for a versatile and winter hardy tree. ‘Dolgo’ produces red fruit in the fall that is suitable for canning. Otherwise plant Crabapples for their spring colour and small to medium stature.
Shade: what kind? For filtered shade, that will provide the cooling effect of a deciduous tree (one that drops its leaves each fall) without cutting out ALL of the sunshine, look for these winners:
a. Locust. ‘Shademaster’ is hardy to zone 4 (Ottawa). This variety features horizontal branching, while ‘Skyline’ Honey locust produces a more upright, vase shaped structure. Both are disease and insect resistant and grow to a medium height of about 12 to 15 meters.
Birch. A long time favourite, not just for the filtered shade that they produce but the lovely white bark that stands out in the winter garden. Look for native birch, like Paper Birch [Betula papyrifera], as they are resistant to the dreaded bronze birch borer, which has wreaked havoc with the European birch species in recent years.
Kentucky Coffee Tree. [Gymnocladus dioicus] A native, open-growing tree with characteristic short, stubby twigs for branches. Foliage turns yellow in fall. Grows to 15 meters but it is slow to become established. Kentucky Coffee tree is so named as you can roast the seeds as a (poor) substitute for coffee. However, the raw seeds and pods are toxic.
Early shade/dense shade. Not all deciduous trees leaf out at the same time. Birch, willow and maples are among the earliest (early May) and Catalpa and Rose of Sharon are among the latest (mid-June). For early leaf cover, that lasts late into the season, consider:
Maple [Acer]. Native sugar maples leaf out in early May and drop leaves in mid to late October. Norway Maple, while deemed an invasive species, does leaf out marginally earlier and drops in early November. Both produce bright yellow colour come fall.
Chestnut [Aesculus] A member of the orchid family. Have a close look at the flowers come early June and note that the upright panicle or ‘candelabra’ features dozens of gorgeous orchid-like flowerets. I love Chestnut trees but they are susceptible to blight which may not kill them but creates brown-hued leaves that are not very attractive come late summer.
My favourite all-round trees. There are some trees that do not fit neatly into a single classification but are amazing for their own reasons. Here are my favourites:
a. Linden. [Tilia cordata] related to native Basswood. Provide lovely, cool, dense shade. Produce fragrant (green) flowers that attract pollinators (and make great tea). Lindens are winter hardy and disease resistant. They feature a formal ‘ace’ shaped structure that fits neatly into relatively tight spaces. There is a promenade of Lindens on the east side of the Royal Conservatory and west side of the Art Gallery of Ontario that will sell you on this species, if nothing else will.
b. Japanese Tree Lilac ‘Ivory Silk’. [Syringa reticulata ‘Ivory Silk’] Ivory Silk is an oval shaped, compact tree (great for smaller lots and spaces) that blooms reliably each Father’s Day in mid-June. Winter hardy on the prairies. Disease and insect resistant. Nothing not to like.
Oak. Any oak is a great oak, but I like native Red oak [Quercus rubra] and Pin Oak [Quercus palustris] best. Red oak (so named as the wood is red) grows into a large 18 meter giant. There are some heritage Red Oaks in High Park that are amazing. Pin Oak is narrower and more suitable for the tight spaces of urban life.