Watersprouts vs. Suckers—What’s the Difference?
Woody stems that spring up from the roots of a tree are called suckers. Suckers are most common on trees that are grafted to different rootstock than the upper portion of the plant. If left in place, a sucker can grow into a second trunk and compete with the main tree. Because suckers usually develop from the rootstock of a grafted plant, the sucker will likely have a different leaf shape, growth habit, and size than the main tree. Watersprouts emerge from a tree’s trunk and branches with vigor equal to suckers. These fast-growing, upright stems often grow in clusters of 10 to 20. They commonly grow where a large branch was removed or near a part of a tree that experienced storm damage. Watersprouts are a tree’s way of generating branches quickly. This can be a good thing when a tree is recovering from damage but it’s not helpful for an otherwise healthy tree.
What Causes Watersprouts and Suckers?
Both watersprouts and suckers are a tree’s way of telling you it’s experiencing stress. When trees suffer stress from storm damage, root compaction, over-pruning, or disease, they often respond by putting out loads of new growth, attempting to compensate for the loss. Reduce the wild, unwanted growth by reducing the tree’s stress and preventing it when possible. When it comes to stress-related causes, suckers are a little different than watersprouts. Suckers might form because the top of the tree is not perfectly compatible with the rootstock it is grafted to. In this situation, there’s nothing you can do to reduce stress response. Simply plan to remove suckers as soon as you see them.
Tips for Removing Watersprouts and Suckers
Protect a tree’s nutrient reserves and preserve its structure by pruning off watersprouts and suckers. Take management one step further by preventing the vigorous stems from emerging in the first place. Here are 5 essential tips for removing and preventing watersprouts and suckers.
1. Be Vigilant
The best time to remove watersprouts and suckers is when they are tiny. Not only are they easiest to remove when small, but removing them when they are young prevents them from stealing excessive nutrients from the tree. Keep an eye out for offending growths, especially in spring and early summer when trees are actively growing new shoots.
2. Cut at the Base
Remove water =sprouts and suckers by pruning them off at the base of the shoot. Small watersprouts can usually be plucked off a branch or trunk by hand. Use sharp pruners to remove large sprouts. Suckers require a little more effort. Pull back the soil around the base of the sucker and clip it at its base.
3. Look for Stressors and Remedy Them
Suckers and watersprouts most often grow as a response to stress. Examine your tree for stress, considering the root zone as well as the canopy. If disease is present, take action to treat it. Avoid over-pruning; remove no more than one-third of a tree’s canopy at one time. If storm damage greatly reduced the tree’s canopy, know that suckers and watersprouts are one of the ways the tree is recovering and judiciously remove the sprouts and suckers over time. If root compaction is a potential cause of stress, check with an arborist for remedies.
4. Skip the Spray
There are products that claim to prevent suckers and watersprouts. Little research has been done on their effectiveness and their impact to the parent plant. Don’t use prevention sprays. Likewise, don’t use herbicides to control these growths. Herbicides will likely damage or kill the tree.
5. Avoid Trees Most Prone to Watersprouts
Crabapples, oaks, maples, dogwood, linden, and most fruit trees are prone to producing suckers and watersprouts. These species will benefit from frequent pruning to remove the growths and maintain a strong, healthy branching structure.
