It’s tree planting season and we’re highlighting SDOT’s ongoing work to help grow and take care of Seattle’s urban forest.
The time has come to get your trees in the ground
Why do we plant trees in the fall and winter instead of spring or summer?
Digging trees out of a nursery with ideal growing conditions, then planting them along a city street can cause an effect known as transplant shock. This has the potential to kill a tree, so we plant trees while they’re dormant during fall or winter months.
During the months between Halloween (October) and Earth Day (April), many trees slow down their growth and enter a period of dormancy as daylight decreases and temperatures cool. When the trees shoot new leaves, stems, and roots, they will have a whole spring and summer of growth to better adjust to the new, harsher environment where they’re planted.
Planting during the fall and winter also helps avoid the effects of summer heat, drought, and ground level ozone that forms in hotter conditions, which makes transplanting trees during the summer more challenging and risky. Planting trees in the fall and winter months offers better outcomes for trees to continue growing and thriving throughout the year.

