Many of us are enchanted by the unique beauty of dahlia flowers! However, these pretty blooms can also fall victim to several pests.
Seeing your dahlia leaves devoured by unknown insects can be heartbreaking, and will probably leave you wondering what exactly it is that is eating them. If you are here to find out who is the culprit, then read on as we reveal the most common dahlia pests and quick solutions to get rid of them.
What is eating my dahlia leaves? Causes and fixes
Dahlia flowers are beautiful, multi-petaled blooms that are super-easy to grow. Unfortunately, they are also a favorite snack for several garden pests that can cause extensive damage to the leaves in just a night!
If you are baffled about which garden visitors are devouring your gorgeous plants every night, then do check our list below as the culprit could be one of these:
1. Snails and slugs
Snails and slugs are omnivores that feed on decaying plant matter, fungi, and a variety of garden crops and flowers. As long as their population is kept to a healthy size, these slimy creatures can help clean up your garden by feeding on dead plant matter. Snails and slugs also serve as a food source for some insects and smaller animals, thus keeping the ecosystem balanced.
However, these soft-bodied pests can also cause great damage to your garden if their population becomes unmanageable. Snails and slugs can quickly consume the foliage of your dahlias and other garden plants which have taken you so much time and effort to grow. One tell-tale sign of a snail or slug infestation is the presence of slimy trails around the affected flower beds.
Here are some natural ways to get rid of snails and slugs in the garden:
- Place natural barriers and repellents such as rough mulch, crushed eggshells, nut hulls, diatomaceous earth, or wood ash around your dahlias.
- Invite natural predators like beetles, birds, toads, ducks, and chickens into your garden.
- Use homemade traps like overturned flowerpots, inverted saucers, grapefruit halves, and boards.
- Grow aromatic herbs and flowers that snails and slugs hate, such as rosemary, sage, nasturtium, California poppy, geranium, fuchsia, and impatiens.
2. Caterpillars
Butterflies and moths can be lovely and beneficial for our gardens, but not caterpillars! These wriggly garden pests are voracious plant eaters and will consume any greens they can find, be it a vegetable crop or an ornamental plant. Unfortunately, your precious dahlia flowers are also one of their favorites!
Caterpillars typically leave a distinct chewing pattern from the outer edge towards the middle part of the leaves. They also love hiding inside the curled dahlia leaves as they continue to feed on the plant. So, if you notice rolled, curled leaves on your beautiful ornamentals, then it is probably a sign that caterpillars have been feasting on them.
Here are some effective ways to eliminate the caterpillars in your flower garden:
- Check the leaves of your dahlias in the early morning or evening and try to manually remove any caterpillars you see. This natural method is often the best way to control the early stages of infestation.
- Use natural microbial insecticides on the leaves that contain Bacillus thuringiensis kurstaki to get rid of moth and butterfly larvae.
- Introduce natural predators into your garden, such as birds, toads, and frogs, to manage the caterpillar population.
3. Grasshoppers
Although grasshoppers are not a major threat to your dahlias, these insects might occasionally munch on their leaves, too. Like any other pests, grasshoppers can become a gardener’s nightmare if they are present in excessive numbers. One way to tell if your dahlias have fallen victim to grasshoppers is if you see round or ragged holes around the leaf margins and in between the leaf veins.
Unlike snails and caterpillars, it can be difficult to manually remove grasshoppers as they tend to jump very quickly. The best thing you can do is discard the damaged plant parts and try these solutions:
- Spray nosema locustae around your dahlia plants to get rid of the pests.
- Dust the plant leaves with all-purpose flour – this will gum up the grasshoppers’ mouthparts and prevent them from munching on the leaves.
- Spray the leaves with strong-scented substances to repel the insects. Create your DIY spray using one or a combination of these ingredients: garlic, rosemary, onion, cilantro, cayenne pepper, neem oil, and peppermint oil.
4. Thrips
Thrips are small insects with cigar-shaped bodies and fringed wings that feed on a variety of plants. They damage dahlia flowers by puncturing the plant’s leaves and sucking the sap from the tissue inside. The bites from these tiny pests can also spread a mosaic virus to your garden crops and flowers.
Unfortunately, it can be challenging to catch these little insects since they can quickly crawl or fly to another plant. Thrips can also reproduce fast and engulf your entire garden, so make sure to act right away at the first signs of infestation!
Follow these tips to get rid of garden thrips:
- Remove the pests by forcefully spraying the plant leaves with water. Do this three times a day every two days.
- Apply insecticidal soaps and neem oil to the affected leaves.
- Add beneficial insects to your flower bed, such as ladybugs, Trichogramma wasps, predatory mites, and lacewings.
5. Earwigs
Earwigs can be a gardener’s friend or foe. For starters, these tiny omnivores can be very helpful in controlling unwanted pest populations in your compost pile by feeding on mites, aphids, certain nematodes, and insect larvae. Earwigs also love eating decaying plant matter in your garden, just like snails and slugs.
Unfortunately, earwigs can also eat your garden vegetables and ornamental plants, including your gorgeous dahlia flowers. These pests love munching on plant leaves and flowers, causing irregularly-shaped holes in their wake. Earwigs can also tunnel into the stems and flower buds and settle at the base of your plants.
Before their population grows out of control, it is very important to get rid of the pests at the earliest opportunity. These organic solutions should help you manage the infestation:
- Sprinkle a bit of diatomaceous earth around the base of your infected plants. We highly recommend using Safer Brand; this product is very effective for indoor and outdoor use.
- Add natural earwig predators into your garden, like birds, frogs, parasitic wasps, and spiders.
- Place earwig traps near the affected plants. You can use an old box with small holes and oatmeal as bait.
- Use nematode Steinernema carpocapsae to control the earwig population in your garden.
6. Aphids
Aphids are another pest that dines on your dahlias’ leaves. They are tiny and almost invisible to the naked eye, and might be yellow, brown, black, or green. And, like other plant pests, aphids can eat away the leaves of your plants and cause extensive damage to your flower bed.
If you think your dahlia leaves are being eaten by aphids, do not despair. Follow these quick fixes to instantly kill the nuisances:
- Spray the infected leaves with a mixture of water and Dawn dishwashing soap.
- Apply natural insecticides like neem oil and horticultural oil whenever you see the little insects crawling on the leaf surfaces.
- Add beneficial insects into your garden, such as ladybugs, parasitic wasps, and lacewings. These natural predators love eating aphids and other destructive pests.
Do birds eat dahlias?
Birds do not eat the leaves of dahlia flowers. However, they do love eating insects like caterpillars that might be present in your plants. So, it is possible that these natural predators might slightly damage the leaves in the process.
Do rabbits feed on dahlia leaves?
Rabbits are not big fans of dahlia plants. However, these critters might still munch on the young dahlia leaves if they cannot find any other suitable food. Dahlias consumed in small quantities are not considered toxic to bunnies, so your pretty flowers might not be totally rabbit-resistant!
Do deer eat dahlias?
Although dahlias are not included in a deer’s favorite menu list, these four-legged visitors might occasionally munch on your favorite plants if their preferred food sources are sparse. So, never be too complacent!
To prevent the hungry animals from attacking your dahlias, make sure to deer-proof your garden by putting up a fence. Remember that deer can jump over an obstruction as high as eight feet, so your fence should ideally be at least that tall!
Other threats to your dahlias
Aside from garden pests, certain other creatures can also consume and damage your ornamental plants. Some animals like squirrels, rats, gophers, voles, and chipmunks can devour dahlia bulbs as well as other plant bulbs in your garden. Make sure to keep an eye on these common four-legged pests and set up effective deterrents to keep them away from your garden.
Conclusion
Dahlias are undoubtedly attractive to many garden pests such as mollusks, caterpillars, thrips, grasshoppers, earwigs, and aphids. Thankfully, there are natural ways to get rid of these nuisances without using any harmful chemicals. However, for severe infestations, your last resort might be a stronger pesticide. Make sure to use these harsh chemicals with caution, though, as they can be toxic to both beneficial bugs and humans.
Image: istockphoto.com / Jonas Rönnbro