The best time for transplanting container-grown or balled-and-burlapped conifers is during the spring, summer or early fall, recommends the University of Wisconsin Extension. Although spring and summer are cited as a good transplanting time, trees planted at this time require additional care. Early fall is the best time to transplant a conifer.
The conifer's dormant state during is best for fall planting. Since the tree growth is reduced at this time, this corresponds with the reduced ability of the newly planted roots to absorb and translocate water through the tree. The reduced water requirement of the above ground tree allows the roots to focus on establishing in the soil before active aboveground growth in spring.
If the conifer is to be planted during spring, the best time is very early in the season, as soon as the soil is ready to work. Waiting too late means that the tree starts coming out of dormancy and starts producing new growth. New growth increases demand for water that is hard to supply by the newly transplanted roots.
In case there is no other choice and it is imperative that the conifer be transplanted during summer, the tree requires consistent and regular watering allowing the roots to establish and thrive. Pay special attention to the selection of healthy specimens for summer transplanting. Healthy trees better handle the stress of hot and dry summer weather.