Garden Detective

Suckers create thorny situation for gardener

Garden Detective: Oh, what thorns! This little Washington naval orange tree has sprouted suckers from its rootstock that need to be removed.
Garden Detective: Oh, what thorns! This little Washington naval orange tree has sprouted suckers from its rootstock that need to be removed.

Experts tackle readers’ garden questions.

Q: My young Washington navel orange tree is thriving and sending out new growth regularly. However, I recently noticed that it has sprouted from the trunk a few shoots that are rapidly growing, have long sharp thorns and look nothing like the orange branches. What is this anyway? I am inclined to simply cut them close to the trunk, but thought it best to check first. I am also very curious to know more about this intruder to my tree.

Connie Lavoie, Sacramento

Sacramento County Master Gardener Cathryn Rakich: Your orange tree has developed plant suckers, undoubtedly due to grafting. Citrus are sold as grafted trees. The desired variety (in this case, a Washington navel orange) is grafted onto a hardy, disease-resistant rootstock.

Suckers are branches, often thorny, that sprout from the rootstock below the graft union, which is the diagonal scar on the lower trunk, near the base of the tree. The leaves of the sucker may look different because they are from a completely different type of tree. The rootstock is trying to reproduce.

Plant suckers will drain energy from the tree, eventually affecting the tree’s ability to produce desirable fruit. So it is critical to remove all suckers as soon as possible, regardless of the season.

Young suckers can be pinched off by hand as close to the trunk as possible. For older suckers, use sharp, clean pruning shears. Do not damage the bark of the tree. And try to leave the branch collar, where the sucker meets the tree, to help the wound heal faster.

It is also important to keep your tree in good health. Plant suckers grow when the tree is under stress from things such as drought, overwatering, disease and pests.

Cathryn Rakich is a UC Cooperative Extension Master Gardener for Sacramento County.

Garden questions?

Questions are answered by master gardeners at the UC Cooperative Extension services in Sacramento and Placer counties. Send questions to Garden Detective, P.O. Box 15779, Sacramento, CA 95852. Send email to h&g@sacbee.com. Please put “Garden Detective” in the subject field and include your postal address. To contact UC Extension directly, call:

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