April’s Arbor Day is an annual reminder of how important trees are to our lives. Trees shade our homes, clean the air, sequester carbon from the atmosphere, offer habitat to wild life and provide beauty to our landscapes.
If the 2019 snowstorm or the trending dry years of the past decade or two have knocked out or gradually killed some of your trees and you are considering what type to replant, think about choosing drought hardy trees.
A homeowner does not have to give up anything (size, flowers, beautiful bark or foliage color) to plant drought hardy trees. There’s a large selection of drought tolerant native and non-native trees with wonderful diverse characteristics.
Our climate in western Oregon can be stressful to trees that haven’t developed here and adapted. We have six months or more of saturated soils followed by five months of bone dry soils. This combination of too wet and too dry is not easy for most trees.
Native trees have adapted to these conditions which are likely to stress many non-native trees. And stressed trees are more susceptible to disease, insect infestation and poor growth.
Bigleaf maple, Madrone, Chinquapin, Ponderosa pine, Incense cedar and Oregon white oak, also known as Garry oak, are all native trees that can tolerate our wet winters and dry summers. Since these trees are native to our area, they are all good choices for nature-scaping to provide food and shelter to other forms of wildlife.
Research has shown that over 300 species of insects will spend part of their life cycle in our native oak trees. And it is often these species of insects that provide a food source for many of our native song birds. Without these native trees, our song-bird population will continue to decline.
If you prefer to plant non-native trees, look for those that have similar characteristics to our natives that can tolerate wet and dry seasons and are not invasive. These would include catalpa (native to southeastern US), gingko (China), honey locust (central and eastern North America), Atlas cedar (North Africa), Deodar cedar (Himalayas), mimosa (Australia, Mexico, southwestern US), mulberry (China), Swiss stone pine (central Europe), hornbeam (Europe to Iran and eastern North America), eastern redbud (eastern US), and giant sequoia (Sierra Nevada).
To create a drought tolerant sustainable yard, plant drought-tolerant trees with other drought-tolerant plants in the same area of your garden. Don’t surround drought hardy trees with lawn, shrubs or other plants that need frequent watering. Over watering native trees during summer can lead to root rots.
The best time to plant new trees is during winter on into early March to allow their root systems a chance to get well established before the heat of summer. If the new tree has a good root system and is not a bareroot tree, you can plant up to April 15 with good results.
Your drought hardy trees will do better if you give them a monthly deep irrigation during their first summer in your landscape. And remember to put your trees in the right place. Know if your tree likes full sun or shade, requires a well drained or damp site, and will mature into a big space or a small space.
And finally, remember the good advice slogan of “Look down look up and look around” before planting your tree. This helps to keep you from digging into a utility cable, planting under a power line and not planting too close to a structure. If you plant your tree in the right place for the eventual size of the tree, you won’t be tempted to have the tree topped in the future.