These 5 garden pests can destroy your plants fast. How to stop them now
- Common garden pests like slugs, Japanese beetles, and aphids can quickly destroy plants.
- Signs of infestation include holes in leaves, visible pests, and sticky residue called honeydew.
- Control methods range from hand-picking pests and using baits to applying pesticides and pruning plants.
Midsummer means blooming flowers and the beginning of a bountiful garden harvest, but for the unlucky, it also brings a host of pests that can destroy a garden in days.
Aphids, slugs and Japanese beetles are just the beginning; your garden can be home to dozens of unwanted pests that get to enjoy your plants before you do. But how do you get rid of them safely?
USA TODAY interviewed pest control experts, got DIY pest control product recommendations from SC Johnson entomologists, and learned which garden features are likely to attract bugs.
Here's how to protect your garden now from the most destructive pests, according to experts.
5 common garden pests destroying plants, and how to stop each one
Slugs and snails
Sign of infestation:
- Irregular holes on leaves and flowers
- Holes in ripening fruits that are close to the ground (like strawberries and tomatoes)
- You see slugs and/or snails on your plants
Slugs and snails are regular garden pests, and they love to snack on leaves, fruit and veggies. In fact, anything decaying or ripening is fair game for a slug or snail.
They thrive in dark, moist environments. One key to removing them from your garden is to make their habitat inhospitable by removing low-hanging leaves, rocks and weeds that provide that shade. Then, each day, you can pick slugs off your plants or use baits, which are a widespread removal technique.
How to get rid of them:
- Hand-pick slugs and snails off your plants
- Use iron phosphate baits, like Sluggo
- Set out beer-baited traps using cheap beer or a mixture of water, yeast and flour
- Prune lower-level leaves, remove debris and get rid of weeds
Japanese beetles
Sign of infestation:
- You see green and brown metallic beetles
- Holes eaten out of leaves
- "Skeleton" leaves in the garden with nothing but the membrane remaining
- Brown patches on your lawn (sign of grubs)
Japanese beetles typically appear in late May or early June, with peak activity in June and July, but by the time you see one, the damage may already be done. These beetles can decimate entire gardens, leaving nothing but skeletonized leaves in their path.
"They feed on over 300 different plant species, so this is not a pest that sticks to one corner of the garden, which makes them even more destructive," says Ed Dolshun, the vice president of business development and technical director of the pest control company, Catchmaster. Japanese beetles are social feeders that travel in groups to destroy gardens.
How to get rid of them:
- Knock the beetles off infected bushes and into a cup of soapy water
- Apply garden pesticide
- Treat your soil with beneficial nematodes
- Call a pest control company
Aphids
Sign of infestation:
- Tiny, pear-shaped insects that cluster on the undersides of leaves
- Leaves that curl, twist or pucker
- Yellowed leaves or poor/stunted plant growth
- Sticky, clear liquid waste ("honeydew") left on leaves
- Sooty mold (black, powdery fungus that grows on honeydew)
- Trails of ants that go to and from the honeydew
Small numbers of aphids may not kill plants, but large infestations can do significant damage by stunting plant growth. They like to feed on new plant growth and are commonly found in dense groups on leaves or stems.
As aphids eat, they secrete a sticky, clear liquid called honeydew. This shiny substance can be as problematic as the aphids because it attracts ants, wasps and other insects. It can also turn black with the growth of sooty mold fungus.
Aphids can also transmit viruses from one plant to another, which can be particularly damaging to crops like squash, cucumber, pumpkin, melon, bean, potato, lettuce, beet, chard and bok choy.
How to get rid of them:
- Use general pesticides
- Spray (or really blast) your plants with water
- Prune severely infested leaves and plants
Caterpillars
Sign of infestation:
- Irregular holes in leaves or completely skeletonized leaves
- Caterpillar frass that looks like small, dark pellets
- Silk nests, tents or webbed structures
- Caterpillars on leaves or in your garden
One caterpillar isn't cause for concern, but an infestation of hundreds can certainly do some damage to your garden. Caterpillars feast on foliage, and can leave your garden full of holes and skeletal leaves.
Moths and butterflies lay their eggs on plant leaves, and a caterpillar will emerge a few days later. You can pick the caterpillars off by hand or spray with insecticide, but prevention is one of the best methods for keeping your garden safe. You can cover your garden with a fabric insect barrier that prevents moths from laying eggs in your garden.
How to get rid of them:
- Pick the caterpillars off and drop them into soapy water
- Apply general pesticides
- Use natural methods like applying neem oil or a water/vinegar solution to leaves
Whiteflies
Sign of infestation:
- Tiny white nymphs on the underside of leaves
- Yellowing, slivering or drying leaves
- Honeydew on leaves, fruit or under plants
Whiteflies are small white insects that suck the sap out of leaves. The adults will fly around your garden and be a nuisance when disturbed, but it's the nymphs that do the real damage. Nymphs suck the sap out of your plants, leading to yellowing and premature leaf dropping.
Like aphids, whiteflies leave behind sticky honeydew that can turn to black sooty mold. When this fungus covers the plant, it can block photosynthesis and harm your plants.
How to get rid of them:
- Use a plant-safe insecticide
- Spray the infected plants off with a powerful hose
- Apply a soap mixture or neem oil to the infected plants
Do you need professional pest control for your garden?
While there are many DIY pest control products available, they don't always cut it. If you have a larger infestation or can't keep up with the bugs, then a professional pest control service might be worth it.
The major factors you should consider are:
- Cost: DIY products may be cheaper, but you do need to do regular treatments to keep pests out. Professional pest control typically costs between $40 and $70 per month ($80 to $150 per bimonthly treatment), and may not be much more than buying pest products and performing treatments yourself.
- Convenience:Professional pest control is the most convenient option; you don't even need to be home for technicians to spray. Once you sign up for a treatment plan, you get a notification when your treatment is scheduled and a summary of when it's done. For DIY, you have to set aside the time to treat your garden for pests.
- Effectiveness: DIY pest products are sold at less potent doses than what can be used by a pest control company, which can affect how well it works.
Garden features that attract pests to your yard
"Many homeowners don't realise that certain features in their garden can be highly attractive to wasps, particularly during the warmer months when colonies are at their busiest," said John Whiteley-Wilkson, pest control expert at Acorn Environment Services.
In fact, many common garden features can be the reason why you're overrun with pests like stinging insects, ants and more. Here are the most common garden features that attract pests to your yard, according to Whiteley-Wilkson:
- Fallen fruit
- Flowering plants
- Outdoor garbage cans
- Outdoor dining spaces
- Dense vegetation
- Sheds
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