How to Kill Suckers on Grafted Trees

Mechanical Pruning of Suckers

• 1

  Use hand pruners to cut suckers that grow up from the roots of grafted trees. Use lopping shears for suckers more than 1 to 1-1/2 inches in diameter. Cut the suckers off below ground level and recover the root or stump to discourage resprouting.

• 2

  Cut off suckers with your lawn mower if they're more than several inches from the tree trunk, but never mow so close to the tree that you risk hitting the trunk with the lawn mower. Bark injuries from lawn mowers and weed whackers make trees susceptible to disease problems.

• 3

  Avoid pruning off the suckers on cherries, almonds, plums and other members of the Prunus family in fall or early winter. These trees are susceptible to bacterial cankers. The spores for bacterial diseases are released at that time and may land on the fresh wounds, infecting your tree. The best time to prune Prunus species is in late spring or summer.

Chemical Control of Suckers

• 4

  Prune off suckers 10 inches or more in height with pruners or lopping shears, as above.

• 5

  Spray the spots where you removed the suckers with a product containing the plant growth regulator naphthaleneacetate. You will need to reapply the product every three months during the tree's active growing season.

• 6

  Spray small suckers less than 10 inches in height directly with the NAA product. There is no need to prune away these small suckers first, but the smaller the suckers, the more effective the product is.

• 7

  Do not use a general-purpose herbicide such as glyphosate or a product intended to decompose tree stumps to control suckering. These products are absorbed into the tree's vascular system and will weaken and kill your tree.