“When is the best time of year to plant a [tree] sapling?” Question from Julia of Montello, Wisconsin
Answer: Young trees, or saplings, are best planted in early spring before they have fully broken dormancy. The soil must be soft enough to dig before planting. Planting early will give your new sapling a full growing season to set deep roots and new top growth, allowing it to better withstand the cold winter weather of central Wisconsin.
Saplings of very hardy tree species (USDA Hardiness Zones 4 to 3) will overwinter if planted in fall, and larger balled and burlapped trees are also better able to withstand fall planting because they have more stored energy. But overall newly planted trees perform better from transplant shock if planted in spring.
For a good overview or tree-planting methods, read this article about How and When to Plant Trees! I hope this helps!
Happy gardening! Jessie Keith