Q: When is the best time to plant trees in Zone 4?
—Susan M. LeTexier, East Grand Forks, MN
A: Generally, fall and early spring are the best times to plant a tree in cold zones. Young trees have an easier time settling in and establishing new roots when the weather is cool and the soil is relatively moist. But there are a few other considerations when choosing the best time to plant:
- Is the tree deciduous or evergreen? The ideal time to plant deciduous trees is when the plants are dormant and have no leaves. In many Zone 4 locations, that means before mid-May in spring. With evergreens you have more leeway, although they also fare better when planted in cool weather.
- Are the trees bare-root, container-grown or balled-and-burlapped? Bare-root trees should be planted only in fall or early spring. And, if they are planted in the fall, they should be in the ground six weeks before the ground starts to freeze so that new roots can develop before then. Container-grown and balled-and-burlapped trees can be planted any time the ground is workable, but at least six weeks before the ground starts to freeze.
- Oaks, poplars, birch, apples, willows and members of the Prunus genus, such as flowering cherry trees, should not be planted in the fall.
Finally, the ultimate key to success is water. It takes newly planted trees a year to develop self-sustaining root systems. Until then, they’re dependent on you for the water they need to thrive.