Suckers

No, we are not talking about naive carnival “marks” who are easily separated from their money. 

In the garden and orchard, suckers (basal shoots) are new plants that emerge, not from a seed, but from meristem tissue in the root system or at the base of a mature plant. This is a form of asexual reproduction, also known as vegetative reproduction. The offspring created through vegetative reproduction are clones of the mother plant, or genet.

Suckers can be an excellent way to get new, identical plants, or they can suck the life out of a marginally healthy tree. Let’s take a look at suckers and see how they can be used and/or managed.

Fig tree suckers (NativeForeigner) CC BY-SA 3.0

What causes suckers?

Suckers can emerge when a tree is water stressed or as a natural response to warmer weather and moisture. Over pruning can also stimulate a tree to produce suckers. At the same time, regular pruning can help a tree stay healthy without initiating sucker production. And sometimes, trees just put out suckers and we don’t know why.

Spring emergence of suckers

In spring, it is not uncommon to see a cluster of new stems emerging from the base of the tree, or several feet away from the trunk. Most tree root systems are approximately three times the size of the tree canopy. Suckers can emerge anywhere along that root system. If you are trying to create an orchard or want to gift a clone of your tree to someone else, you can use these suckers to your advantage. When removing suckers for propagation, be sure to get some of the root tissue along with the sucker. These baby trees will need lots of TLC to get started: rich soil, frequent watering and filtered sun will help the roots start supporting themselves.

How to remove suckers

Unless you are trying to propagate new trees, all suckers should be completely removed. Suckers pull energy and nutrients from the tree. Removing suckers diverts that energy back into fruit production and the overall health of the mother tree. Do not use herbicides to kill suckers. As long as they are attached to the mother tree, you risk poisoning both.

Unlike other pruning jobs, where a clean cut is desirable, sucker removal is best done by ripping the sucker from its attachment. By tearing, rather than cutting, the bud is more likely to be damaged, reducing the chances of it coming back. If you (or your neighbor) have a tree that you want to reproduce and no suckers are available, you can always try grafting a scion.

NOTE: Most fruit trees are actually two trees grafted together. Horticulturists take the root stock of a growth hardy variety and then graft it to a variety that produces a desirable fruit or flower. You get the benefits of both. The problem with suckers is that they emerge from the root stock and not the fruit-producing variety. This is true of roses, as well. Unless you know for a fact that your fruit tree is not from grafted stock, it is best to tear off suckers and graft scions instead.

Stolons & rhizomes

Stolons and rhizomes behave very much like suckers. Stolons are stems that grow on or just below the soil surface, while rhizomes are roots that grow in the same region. In both cases, adventitious roots emerge from nodes to establish new plants. Strawberries, blackberries, raspberries, potatoes and mint propagate using stolons.