When you buy an ornamental tree from a nursery, like one that produces nuts, fruits, or beautiful flowers, it will most likely have been created by grafting. Grafting is a great way to create perfect replicas of an existing tree, but a tree that has been created by grafting requires extra care.
A grafted tree's roots are from a different tree species, which means that the sucker roots coming from the base of the tree will grow into a different tree entirely. If you don't periodically pull up the suckers or cut them, the rootstock tree can slowly take over the tree that you bought from the nursery. To learn more about grafting and how you can save a tree that has been taken over by its rootstock, read on.
What Is Grafting?
Grafting allows nurseries to create a perfect clone of an existing tree. By attaching a large branch of an existing tree to the roots of the rootstock tree, nurseries are able to create a tree with a trunk from one species and roots from another.
It's necessary for nurseries to use grafting in order to provide a consistent product to buyers, as they wouldn't get a consistent product growing ornamental trees from seeds — the seeds share DNA from two different trees after the ornamental tree has been pollinated, so the resulting tree wouldn't be exactly the same as the original.
Why Are Ornamental Trees Sometimes Taken Over by Their Rootstock?
The species of tree chosen for rootstock is based on its ability to grow rapidly. The fruits, nuts, and flowers that a rootstock species will create aren't taken into consideration, as they'll come from the species of tree that's grafted onto it.
Rootstock trees will periodically send up suckers from their root systems. If these suckers aren't trimmed or pulled, they'll start forming a trunk, and that trunk will have the same species as the rootstock tree. Since rootstock trees are chosen because they grow quickly, it's likely that the trunk of the rootstock tree will grow much quicker than the ornamental tree grafted onto it. Unfortunately, this can result in the rootstock tree covering the original tree's leaves with shade, which deprives it of energy and can kill it.
You can often tell that a rootstock tree is taking over an ornamental tree when you see two or more trunks growing out of the same root bulb. The original tree's trunk will be in the center, and the other trees' trunks come from rootstock suckers that have shot up from the roots.
Can You Save a Tree With Rootstock Growing Around It?
If you have a tree that has been taken over by rootstock suckers, call a tree service in your area and have them see if the original tree is still alive. If it's still alive, it's possible to rescue it by slowly trimming away the rootstock tree surrounding it. Trimming the rootstock trees will allow more sunlight to reach the original tree, which will help it grow.
This is best handled by a professional tree service, as over-pruning the trees can result in them all dying — they're all connected and sharing the same nutrients. Over time, you'll be able to slowly prune all of the unwanted rootstock trees away until the original tree is strong enough to stand on its own. To keep the rootstock trees from coming back, you'll have to periodically check the base of the trees for suckers and pull them out of the ground if you notice them coming up.
For more information on tree service, contact a company near you.