when to stake a tree
Yesterday I planted two Himalayan birches in my front yard in Portland. Both are almost 11 feet tall with trunks about 1.25 to 1.5 inches in diameter. The root balls were 16 inches wide and 12 inches high. Do you recommend staking the trees? It was fairly windy today 5/13/13 and both held up ok.
Multnomah County Oregon trees and shrubs
Good day, and thank you for using Ask an Expert.
As you know, winds in our region can be forceful enough to topple trees. Research trials have shown that staking a tree so that it can sway in the breeze can encourage the development of a sturdy root system even while the trunk thickens and strengthens. One system uses a stake on opposite sides of the tree, each about 8 inches from the trunk and driven into undisturbed soil below the planting hole. The preferred material for “ties” is broad and flat; avoid wire, even if within a hose.
“New Tree Planting” has informative text and instructive illustrations: http://www.treesaregood.org/treecare/resources/New_TreePlanting.pdf
In practice, trees are staked for a brief time, about a year. At that time, the ties can be removed and the tree tested for stability. For the test, grasp the trunk at chest height, then rock it back and forth while watching the ground at the base of the tree. If the soil moves at all, replace the ties, then test again in another year.