Dorothy is a master gardener, former newspaper reporter, and the author of several books. Michael is a landscape and nature photographer.
Some insects are beneficial to your garden, but many are simply destructive pests. These five worst pests can be quite a nuisance, but we're going to talk about how to recognize them or their presence in your garden and how to get rid of them.
5. Japanese Beetles
1. Aphids: They Will Eat Almost Anything
There aren't many plants aphids won't attack, feeding on the foliage and stems, especially during dry days and hot temperatures. These tiny, teardrop-shaped devils will leave your foliage yellow, speckled, mottled, brown and/or wilted.
Some other symptoms of aphid damage are stunted growth, low yields, decreased rates of growth, and death. Because of the way they feed, aphids foster viral and bacterial diseases, both more difficult to control than the population of the aphids.
How to Get Rid of Aphids
- Water or insecticidal soap—you won't want to spray insecticides on aphids because of the threat to the beneficial insects that may be nearby. Instead, blast them with a spray of water from your garden hose, or apply a gentle insecticidal soap.
- Ladybugs—do no damage to your plants and they are fun to watch in your garden. They also will turn your aphid infestations into their own brunch. You can buy hundreds of live ladybugs online from different places. This is my own personal favorite solution to aphids.
- Yellow bowls of soapy water—if you set out a bowl of soapy water, make sure the bowl is yellow (the brighter the better). Aphids are naturally attracted to anything yellow and will jump into the water, but the poor things can't swim a stroke.
You can also buy yellow sticky traps that will attract aphids, but I don't recommend them because they can inadvertently catch beneficial insects.
2. Slugs: Ugly Blobs of Slime
Slugs (and snails), in my humble opinion, are ugly little strips of slime that can make your gardening life pretty miserable, so if you see them, you must get rid of them. They will leave behind unsightly holes in the foliage of your beautiful plants. If you have some potentially prize-winning plants, they will not know the difference and will leave them looking ragged and ruined.
How to Get Rid of Slugs (and Snails)
- Crushed eggshells—if you simply want to protect your plants from slugs and snails, you can spread a wide layer of crushed eggshells around them; they are sharp enough to cut into their bodies and they know not to cross them. The eggshells will keep them away from the plants but they will move on to other ones so I prefer the next solution.
- Kill them—if you are okay with my own preferred "death sentence" for them, either sink a shallow container filled with beer into the ground or place a half-empty bottle of beer on its side. The mollusks will crawl inside the beer and die.
3. Snails: More Slime
Slugs and snails are close cousins as far as garden pests go. Everything suggested in dealing with slugs also applies to snails.
I have no qualms about getting rid of slugs or snails, so whenever I see one, I pluck it off with tweezers and drop it into a bottle of beer to possibly die happy (it's the least I can do), put the lid on the bottle, and throw it into the trash bin.
4. Cutworms: The Sneakiest Pests Around
Cutworms, the larvae (caterpillars) of several species of brown moths, are very stealthy and extremely sneaky, hiding just below the soil during the daytime, only to emerge in the darkness to feed on your plants (especially the ones that are newly planted and tender). Usually, you will see the damage cutworms do before you see the cutworm itself, and the damage is unmistakable.
If the main stem of a plant is small enough, you might see a clean cut at the base, completely toppling; if the base is too thick, they will choose, instead, to climb up and eat around the more tender parts of the plant. The damage is usually seen at planting time, in spring or early summer.
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How to Get Rid of Cutworms
- Plant collars—to protect your plants, you can make a cutworm collar from either paper towels or toilet tissue tubes (see video below).
- Diatomaceous earth—sprinkle diatomaceous earth (a natural powder made of ground-up fossils) around your plants and it will dehydrate and kill the cutworms when they crawl across it (avoid getting it in your eyes or inhaling it).
- Coffee grounds or eggshells—if you don't have diatomaceous earth, you can sprinkle used coffee grounds or crushed eggshells around your plants.
- Create a cutworm-predator-friendly garden—make your yard attractive to the natural predators of cutworms, which are meadowlarks, fireflies, blackbirds, and toads.
5. Japanese Beetles: Two-Month Destruction
In their adult form, Japanese beetles only live for about two months, but during those two months, they can destroy the beauty of your plants by eating away at the foliage, giving it a skeleton-like appearance. They feed on the flowers, fruit, or leaves of more than 300 species of plants, but normally the damage is only cosmetic in nature, which many gardeners find reason enough to get rid of them.
If you have turfgrass, Japanese beetles are your enemy. They will chew the roots, causing the turf to turn brown and die. Grub-damaged turf will pull up easily from the soil.
How to Get Rid of Japanese Beetles
- Drop cloths—cover your plants at night with a large drop cloth and in the morning, when the beetles are the most active, you can remove the cloth and spray the attached bugs with soapy water. You could also put on some gloves, pluck them off by hand and place them in a bottle of soapy water.
- Fermented fruit cocktail—buy a can of fruit cocktail, set it out in the sunlight for a few days so it ferments. Then, open it up and set it on top of a brick placed in the center of a bucket of water. The fermented fruit is very attractive to them and they will try their best to get to it and the water will drown them. Keep this little concoction away from the plants you are trying to protect.
If you live in an area that gets frequent infestations of Japanese beetles, avoid planting things that they favor.
Favored Plants of Japanese Beetles
Least Favored Plants of Japanese Beetles
Northern red oak
My advice is to always choose your plants wisely. Just because these are among the least-favored plants of Japanese beetles does not mean they are immune to infestations if the food supply of the beetles is limited.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2019 Mike and Dorothy McKenney
Mike and Dorothy McKenney (author) from United States on December 03, 2019:
Thank you so much! I appreciate you taking the time to read my articles.
Devika Primić from Dubrovnik, Croatia on December 03, 2019:
Exactly that these the worst pests to have in a garden. Your helpful tips will clear them away and our gardens will be pest free and our plants will grow greatly.