Reversion of Grafted Trees
April 8, 2013
Ever planted a Japanese maple or fruit tree that started out as on variety…only to turn into another variety with completely different foliage or flower? Many trees and landscape plants are grafted. That means one variety with desirable foliage or fruiting characteristics is attached to the root stock of another variety that is perhaps more disease resistant or more tolerant of heavy soils. Basically, you get the best of both worlds with a grafted specimen. The practice is most common with trees such as Japanese maples and most fruit trees, as well as with roses and now even vegetable plants.
Sometimes, however, the graft may not be successful and you may find yourself with a tree that has reverted to the original root stock variety. The Japanese maple you planted for its dark burgundy foliage has now mysteriously begun to “turn” bright green, such as in the photo above. In reality, the existing top growth isn’t really turning another color, but rather the new green growth is emerging from below the original graft union, as seen in the photo below. Because this rootstock growth is often more vigorous, it can quickly overtake the grafted growth.
You may see “suckers” emerging from the root zone of your tree. You’ll need to properly remove these suckers so they don’t overtake your tree. You may also discover new stems that have emerged from the trunk below the graft union. This growth must also be quickly removed.
There are several reasons why a grafted tree may revert to its rootstock growth. Trees that have been severely or improperly pruned can respond by sprouting from below the graft. During times of drought or other environmental stress, your grafted top growth can suffer leaving the more vigorous rootstock shoots to take over. Planted a grafted tree too deeply, meaning the graft union is below soil level, often leads to the tree reverting completely back to the original rootstock.
Proper pruning and health management of your grafted trees and shrubs are key to long term success. If you have trees that have partial reverted to their root stock, give us a call for a home consultation. We’ll work up a plan for proper pruning and fertilization for your grafted trees. firstname.lastname@example.org 214.528.2266