These Garden Pests Don’t Stand A Chance Against Chrysanthemums

These Garden Pests Don't Stand A Chance Against Chrysanthemums

Chrysanthemums contain a group of natural compounds known as pyrethrins, which consist of pyrethrin I and II, cinerin I and II, and jasmolin I and II. These compounds are capable of repelling and even killing insects and other pests while being relatively safe to use around humans, birds, and other mammals. For centuries, chrysanthemums have been cultivated and harvested as a natural means of pest control. In ancient China, people discovered that drying and grinding the heads of chrysanthemums produced pyrethrum powder that could be sprinkled almost anywhere to repel or even kill all sorts of creepy crawlies.

Even today, for organic gardeners, chrysanthemums are a powerful pest control option, and their benefits can be obtained without the need to pick and dry them. When grown in the garden, chrysanthemum flowers can repel a range of pests, including hard-bodied insects, arachnids, flies, tiny mites, and more. Pyrethrins work by over-exciting the nervous systems of insects, paralyzing them. Moreover, the scent of fresh chrysanthemums alone is sufficient to deter many pests. If you’re dealing with pests in your garden, planting a healthy clump of chrysanthemum flowers is a great way to safeguard your precious plants against these common garden invaders.

1. Ants

Ants chewing on leaves

Adisak Mitrprayoon/Getty Images

If you’re looking for a way to ant-proof your yard and protect your garden from ants before the spring and summer seasons arrive, planting chrysanthemums could be the key. Ants aren’t likely to take up residence anywhere near your chrysanthemum beds because they dislike the plant’s strong fragrance. Unlike commercial ant killers, chrysanthemums are generally safe to use around children and dogs, so there’s no need to wait for any poison to dissipate before going outside to play.

2. Spiders

Spider in web on leaves

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If you’re tired of being spooked or even bitten by spiders in the garden, you can solve your spider problems with this stunning fall flower. Like ants, spiders tend to avoid chrysanthemums because of their strong smell, but spiders can also “taste” their surroundings through specialized organs on their legs. These delicate sensory organs will make spiders extra keen to get away from any chrysanthemums you have planted around your home.

3. Ticks

Tick hanging onto grass blade

Erik Karits/Shutterstock

Ticks aren’t insects; they’re actually arachnids. Spiders tend to hunt or ambush their prey, while ticks wait for animals (or humans) to brush up against plants so they can hop on and draw blood. For this reason, Chrysanthemums are a good garden plant to grow near sidewalks or other pathways where unsuspecting people tend to brush up against wild grass, as the pyrethrin will repel and kill ticks in much the same way as spiders. You can also carry chrysanthemums in your pockets or sprinkle homemade pyrethrum powder on your clothes to repel any potential tick hitchhikers.

4. Roaches

Brown roach on plant


Roaches aren’t super common garden pests, as they tend to prefer living closely with humans and feeding on crumbs and food waste. However, they can nest around garden sheds, garages, compost piles, firewood stacks, and other damp, warm places in your yard and eventually find their way inside your home. Planting chrysanthemums may help to repel cockroaches because pyrethrin will paralyze them. You can also grow chrysanthemums in pots near your doors, windows, and other entry points to discourage roaches from entering your house.

5. Mosquitoes

Mosquito on wet surface

Oxford Scientific/Getty Images

Mosquitoes aren’t necessarily bad for your garden, but no gardener wants to battle a swarm while they’re tending to their plants. Pyrethrins in chrysanthemums are toxic to mosquitoes, but even the mere presence of these flowers may lighten your mosquito burden in the summer. Mosquitoes tend to avoid strong-smelling plants, which is why citronella and catnip are often touted as effective repellants. Chrysanthemums contain similar scents and oils that mosquitoes can’t stand, plus their pyrethrin ensures that any bugs still brave enough will meet a quick end.

6. Thrips

White flower with thrips


Most garden pests will die if exposed to chrysanthemums, but against thrips, these flowers work differently. Chrysanthemums won’t kill thrips, but they make extremely enticing “trap” plants, which is why they’re often used in the gardening nursery industry to lure thrips away from other plants. If you frequently deal with thrips in your garden, it may be a good idea to plant chrysanthemums around the edges of your yard to attract them away from your prized produce.

7. Moths

Brown moth on plant


Moths aren’t always a huge threat to the garden, but their larvae can be. Pyrethrins found in chrysanthemums will kill moths so they can’t lay eggs that will eventually hatch and munch on your precious garden plants. You can also dry and crush the flower heads to create a moth-repelling powder. Chrysanthemum is so effective that it’s often used in sprays for killing and preventing moths in closets, carpets, and more!

8. Flies

Housefly on fruit or flower


Next time you’re having a backyard picnic, bring a pot of chrysanthemums to the table. Like moths, adult flies can be somewhat beneficial for pollinating a garden, but their larvae can damage crops, and adults may also spread diseases between plants — and humans. Chrysanthemum is very effective at repelling flies from unwanted areas with its strong scent and pyrethrin content. If you keep livestock or chickens, extracts from chrysanthemums can also be used around their shelters to protect them from biting flies.

9. Mice

Mice hiding in yellow flowers


Mice might be cute, but they can be a nuisance when they start nibbling on all your garden produce or invading your home. Not to mention, mice spread a range of dangerous diseases and leave behind nasty droppings. Chrysanthemum flowers have low toxicity levels when it comes to birds and most mammals, so they can be a good option for how to get rid of mice humanely. These flowers have a strong smell that repels mice, but if they take a nibble anyway, chrysanthemums can also cause nausea and vomiting, so they’ll think twice before eating from your garden again!

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Dr Heidi Parkes

By Dr Heidi Parkes

Senior Information Extension Officer QLD Dept of Agriculture & Fisheries.