How to Get Rid of Bagworms Before They Damage Your Shrubs

You may be walking through the yard one day and notice little cone-shaped bags hanging from the branches of a shrub or tree. At first, they might look like dried leaves, pinecones, or bits of old plant debris caught in the branches.

Unfortunately, those little bags may not be harmless at all. They may be bagworms.

Bagworms are caterpillars that build protective cases out of silk, leaves, and small pieces of twigs. As they feed and grow, the bags get larger and easier to spot. By the time many homeowners notice them, the damage may already be well underway.

The good news is that bagworms can be managed, especially if you catch them early. A little inspecting now can save your shrubs from a whole lot of trouble later.

What Do Bagworms Look Like?

Bagworms are sneaky because they do a mighty fine job of blending in.

Their bags often look like tiny pinecones, dried leaves, or little brown ornaments hanging from the branches. They are usually covered with bits of plant material, which helps them hide in plain sight.

In late spring, the bags may be very small and easy to miss. As summer goes on, they can grow to about one or two inches long.

Inside each moving bag is a caterpillar. The caterpillar crawls along the plant while carrying its little protective case, reaching out to feed on the foliage as it goes.

Which Shrubs and Trees Do Bagworms Attack?

Bagworms can feed on many types of landscape plants, but they are especially rough on evergreens.

Common plants they may attack include:

Arborvitae
Junipers
Cedars
Cypress
Pine trees
Spruce trees
Leyland cypress
Some broadleaf shrubs and deciduous trees

Evergreens are especially vulnerable because they do not always replace damaged foliage quickly. A heavily infested evergreen may turn brown, thin out, and struggle to recover.

Bagworms can also feed on deciduous trees and shrubs, including plants like maples and oaks. These plants often bounce back more easily because they can grow new leaves, but a heavy infestation can still weaken the plant.

Why Bagworms Can Become a Big Problem

One little bag may not seem like much to worry about. But bagworms can multiply quickly.

Each female bagworm can produce hundreds of eggs. Those eggs stay protected inside the bag through winter. When the weather warms in late spring or early summer, the tiny caterpillars hatch and start feeding.

The problem is that young bagworms are hard to see. Their bags are small, and they blend right in with the plant. That gives them plenty of time to feed before the damage becomes obvious.

By late summer, bagworms are larger, tougher, and much harder to control with sprays. That is why early action matters so much.

Inspect Shrubs and Trees Regularly

The easiest way to control bagworms is to find them before they take over.

Take a few minutes to inspect your shrubs and trees closely. Look for small brown, spindle-shaped bags attached to the branches.

Pay extra attention to arborvitae, junipers, cedars, Leyland cypress, and other evergreens. Do not just glance at the outside of the plant. Gently look deeper inside the branches too.

Bagworm cases can blend in surprisingly well. What looks like a dried leaf may actually be a caterpillar carrying around its own little camouflage tent.

Remove Bagworms by Hand

If you only see a few bags, hand-picking is often the easiest and best solution.

Put on a pair of gloves and pull each bag from the plant. Then place the bags in a sealed trash bag or drop them into a container of soapy water.

Do not toss the bags on the ground beneath the shrub. Eggs inside the bags may still hatch and start the problem all over again.

Hand-picking works especially well in fall, winter, and early spring before the eggs hatch. It can also help during summer if the plant is small enough to inspect thoroughly.

Treat Bagworms While They Are Small

If there are too many bagworms to remove by hand, you may need to use an insecticide labeled for bagworms on ornamental plants.

Timing is important.

Treatments work best when the caterpillars are young and actively feeding. In many areas, this is in late spring or early summer.

Products containing Bacillus thuringiensis, often called Bt, may help control young caterpillars. Spinosad is another ingredient commonly used for caterpillar control.

Always read the product label carefully before applying anything. Make sure the product is labeled for the plant you are treating, and follow all mixing, application, and safety directions.

Good spray coverage matters because the bag protects the caterpillar. Once bagworms get larger, treatments may not work as well.

Be Careful Around Pollinators

Use extra care when applying any insecticide near blooming plants.

Avoid spraying flowers while bees, butterflies, and other pollinators are actively visiting. Whenever possible, hand-pick bagworms or use targeted treatment instead of spraying the entire yard.

Only treat the plants that need it, and always follow the directions on the product label.

Will Damaged Shrubs Recover?

Whether a damaged shrub recovers depends on the plant and how much damage was done.

Deciduous shrubs and trees may recover if they only lose some leaves because they can often produce new foliage.

Evergreens are a different story. Arborvitae, junipers, cedars, and similar plants may not fill back in once large sections turn brown or bare. Some damaged areas may stay thin for a long time.

If the damage is severe, prune away dead branches when appropriate and keep the plant watered during dry weather. Avoid heavy fertilizing during extreme summer heat because that can place even more stress on the shrub.

How to Prevent Bagworms Next Year

The best time to reduce next year’s bagworm problem is before the eggs hatch.

During fall and winter, inspect your shrubs and trees for old bags. Remove and destroy every bag you can find.

A little time spent checking your plants during the cooler months can prevent a much bigger mess the following summer.

You can also help your shrubs stay stronger by watering deeply during dry weather, adding a proper layer of mulch, and avoiding unnecessary stress.

Final Thoughts

Bagworms may be small, but they can cause serious damage when they are ignored.

Check your shrubs and trees regularly, especially evergreens like arborvitae, junipers, cedars, pines, spruce, and Leyland cypress. Remove visible bags by hand whenever possible. If treatment is needed, act while the caterpillars are still young and easier to control.

Catching bagworms early is a whole lot easier than trying to rescue a badly damaged shrub later in the summer.