An infestation can devastate vegetables, shrubs, and flowers within a matter of days, so you need to know how to get rid of caterpillars on plants quickly and safely.
Caterpillar outbreaks aren't as common as aphids or mites, but they still infiltrate gardens and can do serious damage.
Luckily, learning how to get rid of caterpillars comes down to choosing the right tools for the job - and following these simple tips for identification, prevention, and control.
Signs Of A Caterpillar Infestation
There are several telltale signs that caterpillars are wreaking havoc on your garden. Usually, they’re most active during the hot summer months.
If you notice that your leaves or shoots are chewed off at the base, it’s probably a caterpillar problem.
You might also find holes in leaves or discover that the leaf edges of your plants have grown ragged.
Sometimes, leaves will look as though they are fastened or rolled up with silk. Worse, you might see these tiny pests themselves as they crawl all over your plants.
Are All Caterpillars Enemies In The Garden?
Not all caterpillars are identical, and not all caterpillars are bad for your plants.
There are also many pests that are referred to in general terms as caterpillars, like cutworms.
While some caterpillars turn into moths, others turn into butterflies - meaning you might not necessarily want to kill them, as they could be beneficial for your garden later on.
Before waging war on your caterpillar infestation, try to identify the type of caterpillar that has taken over.
The most important caterpillar to leave alone is the caterpillar form of the Monarch butterfly. This migratory species is in decline so it’s important that you give these individuals free rein.
Usually, they won’t target your garden plants, though - they’d rather feed on milkweed plants instead.
How to Prevent Caterpillars
A lot of the issues with caterpillars come from crop selection, but in reality, there isn't too much that can be done to prevent them since you are growing outdoors, in their home.
However, we have a few tips to mitigate the chances that a caterpillar outbreak occurs in the first place.
Plan Crops Carefully
Usually, caterpillars and other like-minded pests will target the same kinds of plants repeatedly. They won't usually go after plants that are different from each other, like lettuce and eggplant.
To make the most of your garden space and prevent pests like caterpillars, rotate your crops every year.
Don’t grow plants in the same family in the same place each year but instead, pick new spots. This can also prevent the outbreak of disease, too.
Plant Caterpillar Repelling Crops
There are several types of plants that repel caterpillars, including lavender, sage, mugwort, and peppermint.
For whatever reason, caterpillars aren’t fond of the strong odors that these plants release.
To keep caterpillars away, plant a few around the perimeter of your garden.
Use Cardboard Rings
Some types of caterpillars can be deterred by placing cardboard rings around your plants.
You can cut these out of old toilet paper tubes and place them around the stem when you transplant your seedlings.
Use Barrier Fabrics
Using a barrier fabric, like a row cover, can easily keep caterpillars off your plants.
You will need to put the row cover on your plants before the caterpillar eggs are laid - otherwise, you’ll just be giving the eggs room to hatch and the babies the opportunity to flourish!
Put row covers on at the beginning of the growing season and remove them only when your plants start putting out flowers.
That way, they can still be pollinated but won’t be targeted by caterpillars.
How To Get Rid Of Caterpillars In The Garden
Like we just said, there is only so much that can be done to prevent caterpillars. There isn't much stopping them from infiltrating your garden and making it their new home.
But all is not lost - there are plenty of ways you can eradicate them from your garden.
Now, we're going to teach your how to get rid of caterpillars on plants if you do encounter them. We have methods ranging from manual removal to chemical intervention. We'll start with the least invasive, for minor caterpillar issues.
Manually Remove Caterpillars From Plants
Get in the habit of inspecting your plants daily. Not only will this help you keep abreast of any issues that your plants might be having in terms of disease or watering problems, but it will also help you spot a caterpillar infestation before it becomes widespread.
Once you see one caterpillar on a plant, that’s a good sign that more are going to follow. Check the tops and bottoms of each leaf for eggs.
These can be laid one at a time or in clusters. Remove every caterpillar, dropping it into a bucket of soapy water.
If the leaf is completely covered in eggs, you may want to remove the entire leaf and take it far from the garden.
You may also notice caterpillar nests from nearby plants or trees. These look like they are spun from silk and usually hang from the branches.
Use a long stick to penetrate the nest and dispose of its contents in a bucket of soapy water.
This is best done first thing in the morning, when the caterpillars are still inside.
Attract Or Purchase Beneficial Bugs
While caterpillars might not be on your list of favorite snacks, there are plenty of insects and animals that absolutely love them.
If you’re trying to keep caterpillar populations at bay, you might want to bring some new wildlife to your garden.
There are all kinds of beneficial bugs that enjoy eating caterpillars, like ichneumon wasps (a species of predatory wasp that does not sting people), chalcid wasps, nematodes, and trichogramma.
You can purchase these wasps online and release them into your garden or you can grow plants that attract the wasps naturally, such as parsley and carrot.
You’ll have to let the plants go to flower in order to see results, though. If you need them quickly, don't waste time planting. Just buy them online and get them sent to you overnight.
You can also attract birds that eat caterpillars, like nuthatches, warblers, orioles, and chickadees.
Set up a birdbath or bird feeder to encourage these animals to visit your garden.
Make A DIY Chili Spray
Caterpillars aren’t fans of spiciness - so chilis can be effective weapons in your war against these pests.
To make a DIY chili spray, simply grind up three and a half ounces of chili peppers in a food processor.
Add the powder to half a gallon of boiling water and let the mixture steep for five minutes before adding half a gallon of cold water and a few drops of dish soap.
Let the mixture cool then apply it to the affected plants. Wait 24 hours to see results. You can apply this spray as often as you’d like!
Use Plant Washes & Neem Oil To Get Rid Of Caterpillars
There are all kinds of products we carry here at Hydrobuilder that you can use to get rid of caterpillars.
Neem oil & plant washes are a great natural way to prevent or eliminate bugs on your plants.
The benefit of using these is that you won’t have to worry about harming beneficial pollinators in your area, like butterflies and bees.
Neem oil, which is made out of neem tree seeds, dissolves quickly and can be sprayed at dusk to avoid harming bees.
Use Insecticides To Get Rid Of Caterpillars
If you have a serious infestation, your best bet is to use a chemical product specifically formualted to kill caterpillars quickly.
Many of the insecticides used for caterpillars will not harm you, your plants, or the environment, so you can restore balance to your garden without worry.
Look For Products With Bacillus Thuringiensis
If you’re trying to get caterpillar populations under control, you should find products that contain Bacillus thuringiensis var. Kurstaki.
Bacillus thuringiensis is typically sold as a spray. Bacterial sprays like this one, which is also referred to as Bt, contain bacterial organisms that attack the specific pest species but don’t harm humans.
As a naturally-occurring soil bacteria, Bt will destroy the lining of the caterpillar’s stomach and cause it to starve in just a few days.
You’ll need to pay attention to the appropriate dilution rates, as these can vary depending on the plant you are trying to spray. Always read the manufacturer’s directions before applying.
Here are some of the top pesticides to help you get rid of caterpillars on plants quickly.
- Safer Brand Caterpillar Killer Concentrate
- Monterey Lawn & Garden B.t. Concentrate (OMRI Listed)
- Bonide Captain Jack's Deadbug Brew Concentrate Concentrate (OMRI Listed)
Final Thoughts On How To Get Rid Of Caterpillars On Plants
The best line of defense you have in your garden, both against caterpillars as well as other pest species, like aphids, is to be aggressive in your tactics.
You’ll want to be patient, as many of these tactics take some time to be effective.
However, now that you know how to get rid of caterpillars on plants, you are set up for success if you do encounter them.
By planning ahead and tending to your garden on a daily basis, you’ll stay abreast of problems before they ever really become problematic - caterpillar infestations included. We have an article covering the top insecticides and fungicides of the year if you want to be prepared for other pests & diseases.
If you need any help finding the right approach to your infestation, reach out to our experts at 888-815-9763 or by email here. We'll help you come up with a game plan and recommend the right product for your infestation.