There are literally hundreds of common garden pests that can attack your plants and threaten the viability of your gardening efforts. We couldn’t possibly address all of them.
There are, however, some that occur in more frequency than others.
Common Garden Pests
Aphids are probably the most common problem in gardens. Aphids are soft, pear-shaped, and very tiny (1/16 to 3/8 inch long). Two short tubes project backward from the tip of their abdomen.
Aphids have long antennae. Some types of aphids have wings, which are transparent, longer than their body, and held like a roof over their back. Aphids may be green, pink, yellowish, black, or powdery gray. Nymphs resemble adults but are smaller and wingless.
They feed in colonies, so where there’s one, there’s definitely more. Aphid feeding can cause leaves to curl and become deformed. Once this has happened, the aphids are protected from any treatment you give to the plant, so it’s important to attack the problem as soon as possible.
Many species prefer the underside of leaves, so look there first. Ants are usually present where aphids are, so if there are ants in the garden, there are probably aphids as well. Aphids are the ant’s food source, so they will protect that food warding off predators that might threaten them.
To naturally control aphids, first be sure to drench plants with strong sprays of water from a garden hose.
Keep your plants as healthy as possible, and spray dormant oil to control over wintering eggs. You can also spray plants with insecticidal soap, summer oil, and homemade garlic sprays.
Check Out: 5 Homemade Organic Garden Bug Sprays
If you will be growing cabbage, broccoli, or cauliflower, you could have cabbage loopers. These pests are light green in color with white stripes running down their back.
The larvae can reach approximately 1½ inches long and have three pairs of slender legs near the head and three pairs of larger legs at the rear end. The middle section is legless and is looped when the insect is moving.
The larva is the damaging stage of the cabbage looper.
The young larvae feed between the veins on the undersides of leaves. Large larvae make ragged holes in the foliage and move to the center of the plant where feeding generally occurs at the base of the cabbage head. Large loopers can also burrow through three to six layers of tightly wrapped head leaves.
The best way to control cabbage loopers is to handpick the larvae a few times a week. Attract predatory and parasitic insects to the garden with pollen and nectar plants.
If you find small holes in the leaves of your plants, you may have earwigs. Earwigs are generally dark brown, slender and elongated. They have a pair of “pincers” at the rear of their body and they run more than fly. They have a curved up abdomen and release foul odor when disturbed.
Earwigs will eat holes in the leaves of plants causing them to wilt and die.
In general, earwigs can be beneficial to your garden, but they can get out of control, so you should use the general spray we’ll give you later in the book. There are a number of ways to control earwigs, but trapping them is probably the best way to eliminate them from your garden.
One way we like is to take a shallow dish and place beer in it. Any beer will do. The earwigs will be attracted to the beer, climb in, drink, and die. You can sift out the dead ones and reuse the beer for trapping again. They are also attracted to corn oil, fish oil, or water and vinegar. You can place these in dishes just like the beer.
If the leaves of your plants are finely speckled with yellow spots or a silvery, metallic sheen, you could have thrips. Thrips are very small – about 1/16” – and difficult to see. There are many varieties of thrips and they are of all different colors.
Thrips are best controlled with sprays as we’ve described. You can also spray the plants with soapy water.
Lady bugs will eat thrips as well, so attract those lady bugs to your garden!
Tomato hornworms are the largest caterpillars found in this area and can measure up to 4 inches in length. The prominent “horn” on the rear of both gives them their name.
Hornworms are often difficult to see because of their protective coloring which is green. Not much for the heat of direct sunlight, they tend to feed on the interior of the plant during the day and are more easily spotted when they move to the outside of the plant at dawn and dusk.
Hornworm damage usually begins to occur in midsummer and continues throughout the remainder of the growing season. The size of these garden pests allows them to quickly defoliate tomatoes, potatoes, eggplants, and peppers. Occasionally, they may also feed on green fruit.
Gardeners are likely to spot the large areas of damage at the top of a plant before they see the culprit.
The best way to control hornworms is to handpick them off your plants. They are especially susceptible to the Bt bacterial spray we described above, so we strongly suggest using this to control your hornworms.
Slugs are among the most troublesome pests in the garden. They feed on a variety of living plants and decaying plant matter. On plants they chew irregular holes with smooth edges in leaves and can clip succulent plant parts. They can also chew fruit and young plant bark.
Because they prefer succulent foliage, they are primarily pests of seedlings, herbaceous plants, and ripening fruit such as strawberries, artichokes, and tomatoes that are close to the ground. However, they will also feed on fruit of some trees, citrus is especially susceptible to damage.
Slugs are nocturnal and come out at night. They slither under rocks and leaves in the day. Holes chomped into leaves and fruits are telltale signs of slug feeding. A more certain sign of slug activity is the silvery trail of dried mucous that these pests leave in their wake. If that’s not sufficiently convincing, go out into the garden at night with a flashlight and surprise them.
Slug control is actually quite easy. They are rather large, so they can be caught by hand and disposed of. This is another garden pest that be caught by setting out a dish of beer.
While possibly cruel, the most effective way to kill a slug is to sprinkle it with salt. You can trap the slugs by placing a plastic bag in the garden containing two decaying lettuce leaves, 2 cups of bran cereal, and pouring beer over the whole mess. Put the bag out before sundown. In the morning, check to see if the slugs are in there and dispose of them.
Prevent slug infestation by removing dead and decaying leaves. This will remove their primary food source. Coffee grounds and egg shells will also keep slugs away. Just place them around the plants you want to protect at ground level.