Your Cool Home is supported by its readers. Please assume all links are affiliate links. If you purchase something from one of our links, we make a small commission from Amazon. Thank you!
You can get rid of dogwood borers by combining preventive care, targeted insecticide treatments, and physical removal of infested wood.
Dogwood borers are a frustrating pest that can weaken or even kill your beloved dogwood trees if you don’t act quickly.
If you’ve noticed sawdust-like frass near the base of your tree, small holes in the bark, or branches that suddenly wilt, you’re likely dealing with these destructive larvae.
In this post, we’ll walk through exactly how to get rid of dogwood borers, what attracts them in the first place, and the best ways to protect your tree long-term.
Let’s dig into the practical steps so you can save your dogwood and keep it thriving.
Why Dogwood Borers Attack Your Tree
Before you can get rid of dogwood borers, it helps to understand why they choose your tree in the first place.
Dogwood borers are the larvae of a clearwing moth, and they’re drawn to trees that are already stressed, injured, or weakened.
Healthy dogwoods produce a sap that naturally repels these pests, but when the bark is damaged by lawnmowers, string trimmers, or cracks from sunscald, the tree becomes an easy target.
1. The Borer Life Cycle Matters
Dogwood borer adults emerge in late spring to early summer, usually around May and June.
The females lay eggs on the bark, often near wounds, pruning cuts, or the base of the trunk.
Once the eggs hatch, the tiny larvae bore into the bark and begin feeding on the cambium layer just beneath the surface.
This feeding disrupts the flow of water and nutrients, which is why you see wilting branches or dieback.
Knowing this timing is key because you’ll want to apply treatments when the larvae are most vulnerable.
2. Signs You Need to Get Rid of Dogwood Borers
The longer dogwood borers go unnoticed, the harder they are to eliminate.
Look for fine, sawdust-like frass that collects at the base of the trunk or around bark crevices.
You might also see small entry holes that ooze sap, and in severe cases, the bark will peel away easily revealing tunnels underneath.
If a branch suddenly dies while the rest of the tree looks fine, that’s a classic red flag.
Early detection makes it much easier to get rid of dogwood borers before they cause permanent damage.
How to Get Rid of Dogwood Borers with Insecticides
When infestations are active, insecticide treatments are one of the most reliable ways to get rid of dogwood borers.
However, timing is everything because the larvae are protected inside the bark once they bore in.
The most effective approach targets the adults before they lay eggs and the newly hatched larvae before they tunnel deep.
1. Use a Permethrin-Based Trunk Spray
Permethrin is a contact insecticide that works well against dogwood borer adults and young larvae.
Spray the trunk and lower branches thoroughly in late spring, just as adults begin to emerge.
Make sure to cover the bark completely, especially around wounds and pruning cuts where eggs are often laid.
You may need to reapply every three to four weeks through early summer to catch all emerging adults.
2. Try a Systemic Insecticide Like Imidacloprid
For a more long-lasting solution, a systemic insecticide such as imidacloprid can help you get rid of dogwood borers from the inside out.
You apply this product to the soil around the tree’s root zone, and the roots absorb it into the tree’s vascular system.
As borers feed on the bark and cambium, they ingest the insecticide and die.
Apply systemic treatments in early spring before the borers become active, so the chemical is already circulating when they start feeding.
3. Consider a Biological Control with Nematodes
If you prefer a more natural method, beneficial nematodes can be an effective way to get rid of dogwood borers.
These microscopic worms are applied to the soil and they seek out borer larvae, infecting and killing them.
Nematodes work best when the soil is moist and temperatures are mild, typically in spring or fall.
They don’t provide instant results like chemical sprays, but they offer a safe, eco-friendly option for ongoing control.
Physical Removal and Pruning to Eliminate Borers
Alongside insecticides, physical removal is a direct way to get rid of dogwood borers that are already inside the tree.
If the infestation is localized, you can often save the tree by cutting out the damaged tissue.
1. Prune Out Infested Branches
When you see wilting or dead branches, prune them back to healthy wood immediately.
Cut at least six inches below the visible damage to ensure you remove all larvae inside the branch.
Dispose of the pruned wood far from your tree, don’t leave it in a compost pile where borers can emerge and re-infest.
2. Excavate Larvae from the Trunk
For borers in the trunk, you can sometimes physically dig them out with a sharp knife.
Carefully probe into the entry holes and tunnels to locate and kill the larvae.
This method is best for small infestations, and it can be surprisingly effective if you catch them early.
Just be gentle to avoid damaging the healthy cambium tissue further.
3. Remove Severely Infested Trees
If the tree is heavily girdled by borers, meaning the bark is damaged all the way around the trunk, it may be too far gone.
In that case, the best way to get rid of dogwood borers is to remove the entire tree.
This prevents the borers from spreading to other dogwoods in your yard or neighborhood.
After removal, don’t leave the stump in the ground, as larvae can continue developing in the wood.
Preventing Dogwood Borers from Coming Back
Once you’ve managed to get rid of dogwood borers, the next step is keeping them away for good.
Prevention focuses on maintaining tree health and eliminating the entry points that attract borers.
1. Avoid Wounding the Trunk
The number one way to prevent dogwood borers is to stop damaging the bark.
Keep lawnmowers and string trimmers away from the base of the tree, and use mulch rings instead of mowing right up to the trunk.
If you make pruning cuts, do them cleanly and avoid leaving stubs that invite borer entry.
2. Water and Fertilize Properly
Healthy dogwoods are much more resistant to borers, so give your tree what it needs.
Water deeply during dry spells, especially in the first few years after planting.
Avoid over-fertilizing with high-nitrogen products, as this can produce lush, tender growth that attracts borers.
A slow-release, balanced fertilizer applied in early spring is usually plenty.
3. Apply a Protective Bark Spray Annually
Even if your tree looks fine, a preventive trunk spray in late spring can repel adult borers before they lay eggs.
Use the same permethrin spray you would for active infestations, and make it part of your yearly routine.
This is especially important for young dogwoods, which are far more vulnerable than mature trees.
So, How to Get Rid of Dogwood Borers?
You can get rid of dogwood borers effectively, but it takes a combination of timing, treatment, and prevention.
Start by inspecting your tree for signs of infestation, then apply insecticide sprays at the right time in spring.
Prune out damaged branches and physically remove larvae where possible to reduce the population.
Finally, protect your tree from future attacks by avoiding bark wounds and keeping it healthy with proper care.
With a little persistence, you can get rid of dogwood borers and enjoy a thriving, beautiful dogwood for years to come.