You’ve seen them before. Those little, hard balls that seem to grow out of nowhere on the leaves or branches of an oak tree. They have a light beige or brown color, mostly take a roundish shape, and they do vary in size. If we were to summarize them, they just don’t look right. So what are these things? Well, they’re called oak galls, and even though they look like fruits especially when they appear on the leaves, they’re abnormal growths. Let’s look at how to get rid of oak galls.
What are oak galls?
In the simplest terms, oak galls are abnormal growths that form on oak trees in response to insects known as gallmakers. The main gallmakers known to induce oak galls are certain small non-stinging wasps, specifically the horned oak gall wasp and the gouty oak gall wasp.
The process begins when the female gallmaker deposits her eggs in the oak tree. They may choose to do so on any part of the tree, which explains why galls can be found on different parts of the tree including the leaves, stems, branches, and even the roots.
As these female insects lay their eggs, they will inject a certain hormone into the tissues of the plant. The chemical interaction between the hormones and the tree’s growth-regulating chemicals will cause that part of the plant to grow abnormally, forming a gall around the egg.
That way, the gall provides much-needed protection and acts as a food source for the developing larva.
How much damage can oak galls cause?
If you’ve been wondering whether oak galls are hurting your tree, the answer is yes and no. In most cases, the presence of galls will not kill the tree. At the worst, infestations on a healthy tree will only result in early leaf loss.
However, a large infestation on an unhealthy tree can weaken the tree and make it more susceptible to other diseases. And let’s not even get started on the unsightly look that these galls give your trees.
How can you get rid of oak galls?
It’s obvious that you want to get rid of these galls as soon as you see them. After all, who wants their oak trees to be a home for insects and to look like a mess?
Before you take any action, nonetheless, you will want to steer clear of any sources or products that claim to be the cure for oak galls.
There’s no such thing as a magic pill that will make these galls disappear overnight. In addition, there are no pesticides that will kill the larvae inside the galls, simply because they’re protected by the walls of the gall.
So what can you do? If you feel like you need to do something, the good news is that there are a few things you can do to get rid of oak galls.
Step 1: Physically identify galls
You will want to take a close look at your tree and physically identify the galls. This is important because you want to deal only with the affected areas. Developing galls typically look like big seedpods or small, tumor-like growths.
Step 2: Understand the symptoms of gall damage
You will also want to identify the symptoms of gall damage in oak trees. Most of the time, the affected oak leaves will have a dull color and may be blackened at times. The leaves may also curl, and fall prematurely.
Step 3: Prune the affected parts
Once you’ve established that there, indeed, are galls on your tree, and you’ve determined the severity of the damage, the next step is to prune the affected parts. You can step on the galls after removal to kill the larvae growing inside.
Be sure to sterilize your pruning tools before and after use to avoid infecting other parts of the tree or spreading the infestation.
Step 4: Prevent the spread
Even though this is not very effective, you can try to control the spread of oak galls by raking up and destroying fallen leaves and branches.
This will help to reduce the number of gallmakers that can hatch and lay eggs on other parts of the tree. That’s in consideration that they often overwinter in the fallen leaves.
Step 5: Hang bird feeders on the tree
Another way to control the spread of oak galls is to hang bird feeders on the tree. The birds will help to eat the gallmakers before they have a chance to lay their eggs.
Step 6: Use carbaryl
Applying carbaryl to the plant when buds break during spring can prevent the gallmakers from laying their eggs. This will help to reduce the number of galls on your trees.
It’s however, good to keep in mind that this pesticide also eradicates many other insects that are beneficial to the oak tree. Therefore, use it as a last resort and only when absolutely necessary.
Most important step: Keep your tree healthy
The most important step in dealing with oak galls is to keep your tree healthy. A strong and healthy tree can withstand an infestation much better than a weak and diseased one.
Make sure to water your tree during dry periods, fertilize them as required, and see to it that you have the right pH levels.
How to Get Rid of Oak Galls: Concluding thought
It’s obvious that oak galls can be unsightly and cause damage to your trees. However, with the right steps, you can get rid of them, as long as you’re not dealing with a heavy infestation.
When all’s said and done, the best way to deal with oak galls is to take preventive measures. Make sure that your tree is as healthy as it can be. That way, it can withstand an attack and recover quickly.