garden with live plants

The 10 Most Invasive Garden Pests

  1. Aphids

Aphids are small, pear-shaped, soft-bodied, and have piercing, sucking mouthparts. You will see them in dense clusters on the underside of leaves and new growth. Aphids suck out the juices from your plants, and large populations cause substantial damage. Look for stunted shoots, yellow leaves, and a large quantity of honeydew. This substance is exudated by aphids and often turns black due to a mold fungus with a sooty appearance. However, the damage is not uniform, and the symptoms include dieback of leaves, curled foliage, and off-color spots on leaves. Eliminating root aphids, while keeping your plants healthy is the primary objective. Make sure you choose an organic solution when treating root aphids, and all other types of invasive species.

2. Broad Mites

Adult mites are microscopic at about 0.2 mm in length, broad, oval, and yellow-green or pale green. The backs of the females have a white stripe. Broad mites secrete substances and suck plant cells from plants. They prefer developing young plant tissue such as flower buds, young leaves, and growing tips. To identify the damage, look for young leaves with dark brown edges at the base, an exemplary network of brown stripes forming on the leaves, corky brown patches on the main stems, leaf stalks, and collapsed spots on the leaves.

3. Leafhoppers

Leafhoppers are tiny, ranging in size from three to 15 mm. Their wings are directly above their backs like a roof. Both hind legs have small spines. The majority are green, but there are various colors, including the brownish coloration of leafhoppers living in turf-grass. Nymphs are tiny with small wing buds. They attack home gardens, including roses, potatoes, grapes, and apples, to feed on the sap in the leaves. Look for white leaves with stippled spots. Larger populations leave dark excrement on plants.

4. Mealybugs

Mealybugs are unarmored, scaled insects covered in a powdery white wax coating with needle-like mouths. Many species have projections extending from their bodies with the appearance of legs. When on a plant, they look like tiny cotton spots and form clusters. Look for them on stems and the underside of leaves on most outdoor plants such as shrubs and bushes. They suck juices from plants, often attracting ants due to the excretion of a sweet, sticky substance called honeydew. Look for wilted, yellowing leaves.

5. Plant Scale

Plant scales are extremely small insects attaching themselves to host plants to feed. They come in different sizes, shapes, and colors but usually appear as little round, brown lumps on the stems and leaves of plants. They can have hard or soft scales covering the body of the insect. Scales can be oyster-shaped, oval, or round. Look for sooty mold or the sugary honeydew produced while feeding. One of the most visible signs is a blackish mold. Different species feed off a variety of plants. The most common are shrubs, fruit trees, and magnolias.

6. Powdery Mildew

Powdery mildew is a type of fungal disease found in a wide range of plants. As a result, there are numerous species, each preferring different plants. The most frequently affected plants include pumpkins, melons, tomatoes, roses, peas, and beans. Once the fungus has spread, look for a mildew layer containing many spores on the top of the leaves. These spores are carried to other plants by the wind and slow down growth. If left untreated, expect a decrease in both quality and yield.

7. Spider Mites

Spider mites are a type of arachnid and are related to scorpions, ticks, and spiders instead of actual insects. The adults are only 1/50th of an inch in length and oval with a pale or reddish-brown coloration. They live on the underside of leaves in colonies and suck plant fluids by piercing leaf tissue. Look for leaves with light dots. Leaves often become yellow, dry out, and fall off. With large populations, webbing is present on the leaves. Spider mites prefer strawberries, beans, ornamental flowers, melons, eggplant, houseplants, and trees. With marijuana dispensaries opening up all over the U.S., we are also finding that spider mites are attracted to cannabis plants. If you are growing, and notice your plants are under attack, consider an organic solution for combating spider mites on weed.

8. Russet Mites

Russet mites can only be seen without a minimum magnification of 10X when in clusters. Through a lens, they appear as translucent, tapered cylinders in a wedge shape with a yellow tint and just two pairs of legs. These insects suck sap from plants beginning at the bottom and moving upward to continue feeding. Look for curled and yellowed lower leaves, discolored stems, and drooping leaves. Both flowering and green growth become less vigorous. Russet mites prefer blossoms, flowers, and flower resins.

9. Thrips

Thrips are tiny insects with fringed or vestigial wings and asymmetrical mouthparts. The adults are rarely more than one-quarter of an inch in length. The most common adult colors are brown, black, or yellow. In the larval stage, thrips are green or yellow. They attack flower buds, leaf buds, and leaves. Look for silvering on the lower surface of the leaf, leaf loss, and blackened or deformed leaves. Thrips generally feed on the underside of leaves and new growth. Feeding results in crinkled leaves with an upward curl, stunted plants, excessive branching, and delayed growth.

10. Whiteflies

Whiteflies are winged insects with soft bodies and triangular shapes. Look for clusters of whiteflies on the underside of leaves. They suck up plant juices with piercing mouthparts and leave sticky honeydew behind. Honeydew can result in the formation of fungal diseases on leaves, including sooty mold. When they feed heavily, look for extremely weak plants incapable of photosynthesis. Leaves will begin to wilt and turn yellow or pale resulting in stunted growth. Eventually, leaves will wither and fall of the plant. If larvae are present, there will be small white ovals on the underside of leaves.


With so many plant pests just waiting to terrorize your garden, it’s important that you take proper measures to keep them at bay and away from your plant life. Consider natural pesticide control from companies like Trifecta Natural, or similar products to treat your plant life. Using organic solutions to manage your crops will ensure that you are managing and harvesting healthy consumables for you and your buyers.

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