4 Reasons for Brown Pellets Falling From Oak Tree With Remedies 

The brown pellets falling from oak trees which are found in the twigs and leaves of the tree are mainly oak galls created by female wasps and gall mites to protect their grubs after hatching.  

The grubs create galls in the summer season by secreting chemical substances which make abnormal tissue growth of the plant. The plant becomes susceptible to this problem if the plant is stressed due to water stress, salt problem, fertilizing issues and severe insect attack.

Oak plants are always important in furniture making. But the brown pellets or the oak galls that the insects form in the oak trees may weaken the plant. That’s why I have enlisted the remedies for these problems. 

You may check the remedies quickly from the below table-

Plant water stressWater the plant regularly. 
Soil problemsMaintain the soil quality and the soil pH.
Fertilizing issuesProvide enough fertilizer once a year in late winter after pruning. Don’t use much nitrogen
Insects and microorganisms Continue pruning and other cultural practices to make the plant healthy by removing the stresses.

What Are the Brown Pellets In Oak Plants?

Brown pellets that are found hanging in the twigs, leaves and stems of oak trees are called oak galls. Oak galls are the shelters of gall-making insects where the grubs stay and take nutrients.

Gall-making insects like female wasps, gall midges, mites etc. hatch eggs on the internal tissues of the oak plant after entering there. At that time, the grubs or larvae of the plant take their nutrients from those tissues and create some special chemicals inside the plant tissues.

Those secreted chemicals are so powerful that they may interact with the tissues and cause secretion of some growth regulators which creates an abnormal increase of the tissues and thus galls or brown pellets are formed.

When the grubs transform into mature insects, these brown pellets or galls fall from the tree parts and the female insects continue the cycle again.

Why Are These Pellets or Oak Galls formed?-4 Common Causes With Solutions

1. Plant Stress

The first reason that initiates the development of oak galls is plant stress. According to scientific research, when a plant remains under persecution, it creates more sugar. As a result, insects can easily affect the plant. 

In this case, the plant can face complexity for various reasons such as overwatering, underwatering, temperature fluctuation, sunlight problems, humidity perspective and other issues. 

Among them, water stress or drought is the most problematic issue created by underwatering which a plant faces on hot days. On the other hand, hot weather is the most favorable time for the insects to egg laying. That’s why they can enter the plant easily.

Again, as the plant cannot produce food due to underwatering, the insects get a more adjacent position for their establishment. Thus, the plant forms more galls.

Control Measures

Plant your tree regularly though it gets mature. Do not keep your plant under water stress. In hot weather, plants need more watering to develop. A large tree requires it also. So, continue watering your plant regularly when the soil is dry.

2. Soil Problems

Next, the problem that I will describe is related to soil constituents. Sometimes soil pH can also cause a devastating situation for the plant. Excessive alkaline or excessive acidic soil is detrimental the plant growth.

If you do not take remedies for the soil problems, the imbalanced soil pH can hinder the water-conducting system and the root system also cannot work properly. Thus, the soil makes the plant stressed and gall-producing insects can affect the plant without any hassle. 

Control Measures

Check the soil pH with a pH meter and take proper initiatives to fix it if the soil pH is imbalanced. Alkalinity can be fixed by liming using calcium oxide or calcium hydroxide. You can also use gypsum in this case.

3. Fertilizing Issues

The following one is a fertilizing issue that may reduce the plant’s stamina and strength to become resistant to the plant. Fertilizers are essential for the plant. But excessive use of fertilizer affects the plant badly.

The amount of nitrogen material is important for plant health. Excessive nitrogen causes favorable conditions for insect and microorganisms’ growth which may facilitate the creation of galls by the insects.

Control Measures

Apply fertilizer once a year to your plant. Avoid fertilizing in the mid-summer as insect growth is high at that time. The insects will receive the nutrients at a high rate. 

Use fertilizers in the late winter when the insects remain dormant after pruning. You always may not need to Maintain the npk ratio of 10-10-10. Sometimes, you may have to apply a low nitrogen percentage according to the plant’s demand.

4. Insect Attack And Microorganisms

Insects are the main culprit in this brown pellet or gall-making activities. They lay eggs and hatch them which later form grubs and these grubs are the ultimate gall makers. Insects that may create oak galls are-

  • Horned oak gall wasp
  • Gouty oak gall wasp
  • Gall midges
  • Gall mites
  • Psyllids 
  • Aphids 
  • Gall flies

Microorganisms like fungi may inoculate through the injured part that the insects made. They also help the insects in gall-making procedures.

Control Measures

If you think of pesticides to mitigate them, they may not play any significant role in your plant. As they are protected by galls, insecticides will not reach them. Hence, you can try cultural practices. 

Firstly, you have to remove the galls manually from the twigs or leaves where it is remaining. Otherwise, you can continue the pruning activity and remove all the branches that contain galls. 

Besides, you should water your plant perfectly to keep the plant unstressed. The most important remedy for this plant is to keep it healthy. Insects cannot form galls in a healthy plant.

Are Oak Galls Harmful to the Tree?

Oak galls are not too detrimental for an oak tree. But it weakens the plant which can be beneficial for other insects and pathogens. They make some leaves fall. 

The leaves become yellow, losing the green color as they disturb the chlorophyll activities and hinder in making of foods. Thus, the leaves drop out and the plant cannot get enough food for their nourishment and may wilt at a severe stage.

How To Save The Plant From Brown Pellets or oak Galls

Removing the Galls

As using pesticides has no significant effect in mitigating insects and galls, you can use cultural practices. Remove the galls by hand from the leaves, stems, twigs and other parts.


If the plant is large enough, you can consult with expert personnel who can manage your plant. But it is an obvious step to get relief from these oak galls or brown pellets.

Watering is needed to remove the stress of the plant. Most of the time, the plant gets stressed due to underwatering in the summer days. To avoid such stress, water your plant regularly if the soil is dry. 

You can fix a schedule for the watering quality and irrigation method to perform the activities in an arranged way. The water should be non-saline. You can also sprinkle water on the leaves to save moisture loss if the weather is too dry. 


Apply enough fertilizers to your plant in the late winter. Using dilute fertilizer may be helpful for you as they are slow-releasing and don’t affect the root system instantly. But you should be conscious of using nitrogenous fertilizer or urea before applying it. 


You can use mulches to conserve soil moisture. In this case, you may take the help of both natural and artificial mulches. Artificial mulches like straw, rice husk and water hyacinth can conserve moisture and don’t allow the radiation of the sun inside the soil.

As a result, the plant and soil remain cool and the soil can supply moisture to the top of the plants for food processing activities. It will increase the interactions between the soil properties. 


Pruning is the method of cutting or removing the excessive and affected branches that are harmful to the plant. You should select the pruning time first. 

You should not prune on summer days. The grubs come out at that time and they will spread around if you cut the stems and twigs. That’s why you should continue this in winter so that it cannot affect the other plants as the grubs remain dormant during that period.

After proper time selection, cut the excessive parts of the plant, especially the twigs having galls in them. You should also be conscious about the disposal of the galls.

Final Words

Though oak galls are used in making some antibiotics, they should not remain in the trees. I saw many galls forming in my oak plant last summer. Then, I researched a lot about it and found the facts that I stated here.

Forming oak falls are an interesting issue of the plant-pest interaction. But they can harm the plant and create an optimum situation for other problems. So, take proper measures to remove the galls. You can follow my suggestions if you want and try to make your plant vigorous by removing brown pellets falling from oak trees.

James Rivenburg
James Rivenburg
James Rivenburg

James Rivenburg is the founder of plantandpest.com, a passionate gardener with valuable experience and knowledge gained through trial and error. The website has a large community of followers who trust his tips and techniques and have succeeded with his advice. He is always Committed to helping others create a beautiful and healthy garden.

Leave a Reply

Your email address will not be published. Required fields are marked *