How Do I Stop Pests From Eating My Dahlias?

Dahlias are perennial plants closely related to Daisies, Sunflowers, and Chrysanthemums. They are well-loved and look gorgeous in a garden. They can be planted anywhere sunny, as they enjoy having a lot of sun throughout the day. 

However, people aren’t the only ones that love these colorful plants. They attract many pests their way. It’s not just bugs that love these plants, but slugs and rodents too. It can be hard to protect your Dahlias once they become a target for pests. 

For that reason, prevention is the best option. To stop pests from eating your Dahlias you can build a fence, use insect repellents or sharp materials around your plant or try insecticides, beneficial insects, and even hand-removal. 

It is important to work quickly as well, as once your Dahlia loses all of its leaves, it isn’t likely to survive. 

What is Eating My Dahlia Stems?

The most common pests of Dahlias are snails and slugs, but there are quite a few pests that love these flowers. Some other pests include:

  • Caterpillars
  • Earwigs
  • Capsid bugs
  • Thrips
  • Rodents

So your plants can easily be under attack all the time if the proper steps aren’t being taken. 

What is Eating Holes in My Dahlias?

The first step to stopping pests from eating your Dahlias is identifying what pests are eating them. Thankfully, there are signs to help you tell the different pests apart. 

Snails and Slugs

Slugs and snails are easy enough to tell apart. You can often go out to your garden at night with a flashlight to check, as that is when they are most active. Usually, you will find them on the petals or the underside of the leaves. However, you can also look around in the early morning. You will often see slimy trails around your plants. 

Slugs and snails are the most common early in the season. This is because the foliage tends to be more tender and easier for the slugs to eat. 

Aphids and Thrips

Things like aphids and thrips suck the sap of your Dahlias. They usually leave small brown holes, and leaves can get misshapen and start to yellow. Sometimes, the petals on your flowers will even fall off. With these pests, releasing beneficial insects like lacewings and using neem oil can all help you to control the pests. 


Mites start at the ground and go up, so if your lower leaves start with discoloration and a thin webbing that is kind of sticky, that is a sign that they are infesting your plant. You can stop spider mites by taking off some of the bottom leaves and using things like neem oil. 


Earwigs can do a lot of damage to Dahlias. However, they won’t usually kill your plant and can help knock down other pests like aphids and spider mites. So while they can be harmful, if you can keep the populations in check, there is no need to eliminate them. Their biggest sign is heavily damaged flowers and older leaves that look like they have been eaten. 

To get rid of Earwigs remove dark and moist areas around your plant where they can hide, like rocks and dead leaves. 


Caterpillars are also very harmful to Dahlias. They often leave big holes in the center of the leaves. Sometimes, they will also roll the leaves and keep them rolled with webbing. Caterpillars can damage all parts of a Dahlia, including seeds, stems, and flowers. Hand-picking is the best way to remove caterpillars or big predators like birds and spiders. 


Finally, there are rodents. Animals like rabbits, rats, and voles enjoy eating Dahlia tubers. However, they can eat other parts of the plant as well. For these pests, fencing is best, with the fence going at least a foot (31 cm) into the soil. 

What Does Spider Mite Damage Look Like on Dahlias?

Usually, spider mite damage starts from the bottom up, as that is where mites like to begin. Like other insects, they suck the sap out of Dahlias, leaving the leaves to become yellow and often disfigured. The leaves may also begin to wilt and fall off the plant. 

If you look underneath the leaves, you may see a red webbing present. 

It is important to note that insecticides with pyrethrins tend to attract spider mites instead of keeping them away, even if they say they are mite repellents. Be careful if you choose to get an insecticide from the store. Also, mites can quickly develop immunity to chemicals, so if you have to use them long-term, you will want to switch up which insecticides and chemicals you use. 

The exception is oils, which smother the insects and leave no chance for mites to become immune. 

Homemade Bug Spray for Dahlias 

Most insecticides can do more harm than good, killing both beneficial and harmful insects. Since the beneficial ones are the best chance of killing pests, you can make your problems worse by using insecticide. 

However, sometimes, you just need to do something to control pests. There are plenty of options if you want a more natural bug spray. Many people use neem oil, which you just place on your plant, especially under the leaves where the bugs like to hide. You can also use diatomaceous soil around your plant to kill any insect that crawls along the ground. 

As for a proper bug spray, milk, eucalyptus oil, vinegar, and dish soap are all good options. Vinegar and dish soap with water tend to be the most popular. Usually, you can mix three cups of water with one cup of distilled white vinegar and a few drops of dish soap for the best results.

Vinegar works as both an insect repellent and an insecticide. This means you can kill any bug on your Dahlias and keep them away for good. You just have to reapply the spray every few days or after rain. 

Other options are one cup of vegetable oil, one quart of water, and a few drops of liquid dish soap or one part milk with nine parts water. 

How Do I Stop Slugs and Snails from Eating Dahlias?

The best way to keep slugs and snails out of your Dahlias is to create a barrier between them and your plant. While this won’t kill slugs and snails already present, this works as an excellent preventative. 

This barrier can be almost anything. There are special chemicals and sprays, but there are also many natural methods such as eggshells, cocoa shells, mulch, or anything sharp, like wood chips or rocks, and keeping the soil dry.

Copper is considered one of the best options, such as using a thin strip of copper wire around your plants. 

Can You Put Salt Around Plants to Stop Slugs?

Salt can work to keep slugs away, but if you put it too close to your plant, it can also kill the plant. For this reason, it isn’t highly recommended, as the amount of salt you would have to use to keep slugs away will easily kill your plant. Plus, it will soak into the soil when it rains, making it ineffective for the slugs. 

Do Coffee Grounds Deter Slugs?

Coffee grounds can deter slugs and be suitable for plants too. If you have a plant outside that likes acidic soil, such as Dahlias, coffee grounds can be a good option for a fertilizer and slug deterrent. 

Will Dahlias Recover From Slug Damage?

Dahlias can recover from slug damage if a few leaves are still happy and healthy. So it is important to stop slugs before completely killing your plant’s leaves. If necessary, you may need to uproot them and place them in a pot indoors for a while until they can recover. 


Dahlias are gorgeous plants that are wonderful to have in the garden. Unfortunately, humans aren’t the only ones that love them. Dahlias are plants well enjoyed by many pests, including rodents, insects, and even slugs. This means they are a prime target for many animals and can quickly be destroyed by hungry pests. 

Try to safeguard your Dahlias by building fences, using insect repellents, and sharp materials around your plant to keep pests away, but you may have to look at insecticides, beneficial insects, and even hand-removing pests to save your Dahlias. 

If you are planting Dahlias outside, it is a good idea to start pest deterrents early, such as setting up fences and using natural insecticides, so you can prevent the problem instead of trying to stop it.