By: Emily Jack-Scott (Garfield County Colorado Master Gardener)
As a rule of thumb the best times to transplant most trees and woody shrubs is in early spring (as soon as the soil can be worked), or in fall (after leaves drop) – the key factor being that the tree or shrub is in dormancy. In some parts of the country, fall planting is actually preferable since most trees are channeling energy into root growth in autumn, as opposed into shoot and leaf growth in spring. However in Colorado, fall can be less ideal since the ground can be very dry in winter and roots of transplanted trees can suffer additional damage. If you do choose to transplant a tree or shrub this fall, there are several considerations that can improve your odds for success.
Firstly, aim to complete the transplant by the end of October. Transplanting any later in fall or winter will leave little opportunity to help water in the new planting before the ground freezes. New transplants are particularly susceptible to winter drought injury due to the dry winter soils in Colorado. This can be curtailed in part by winter watering, which is critical for newly transplanted trees and preferable for all established trees and shrubs in Colorado (refer to Fact Sheet 7.211 Fall and Winter Watering for more information). Winter drought can also be helped by properly mulching a newly transplanted tree (refer to Fact Sheet 7.214 Mulches for Home Grounds).
The species of the tree also factors into transplanting success. This is in part due to the difference in root structure between different species – with some species having shallower, more fibrous root systems that are better adapted to transplanting, especially in fall. Some types of trees really should only be planted in spring including oaks, fruit trees, poplars, willows, redbuds, and birches. Other species can be more successfully transplanted in the fall such as maples, alders, lindens, catalpas, elms, ashes, and honeylocusts. Conifers such as pine and spruce benefit from being transplanted when soils are warmer.
Whether you choose to transplant a tree or woody shrub this Fall or wait until Spring, ultimately the success of your planting depends on following proper tree-planting steps (refer to GardenNotes #633 The Science of Planting Trees). Happy planting!
Fall and Winter Watering. https://extension.colostate.edu/topic-areas/yard-garden/fall-and-winter-watering-7-211/
Fall Planting of Trees and Shrubs. https://hortnews.extension.iastate.edu/1997/8-22-1997/fallplant.html
Planting and transplanting trees and shrubs. https://www.mortonarb.org/trees-plants/tree-and-plant-advice/horticulture-care/planting-and-transplanting-trees-and-shrubs
When is the best time to transplant trees? http://blog.davey.com/2017/11/when-is-the-best-time-to-transplant-trees-pine-oak-maple-and-fruit/