When you find tiny white bugs on or in the soil of your houseplants, it is usually a reason for alarm. And it is not the only sign that something is off—the plant might also show other signs of an infestation, such as yellowing leaves and stunted growth.
However, not all tiny white bugs are harmful. Before you take any action, it is important to investigate the problem more deeply to make sure it is a problem. This overview walks you through the different types of tiny white bugs you may find on houseplant soil and tells you how to get rid of them.
Culprit #1: Root Mealybugs
What Do Mealybugs Look Like?
This type of mealybug lives beneath the soil. Root mealybugs have an elongated oval shape, about 1/16 to 1/8 long, and their bodies are covered with a waxy white cotton-like substance, which is typical for mealybugs. They move very slowly.
Signs of Mealybug Infestation
Root mealybugs feed on the sap from the plant roots, which causes the yellowing of leaves or leaf edges and drooping of the entire plant, as the nutrient supply is cut off. If you remove the plant from its pot, you will notice that the roots are limp.
Culprit #2: Soil Mites
What Do Soil Mites Look Like?
Soil mites are tiny, smaller than pinhead-size white arachnids that you might find in your soil or compost bin. They are so small that they are hard to identify with the naked eye; they appear like countless tiny white spots in the soil.
Signs of Soil Mites
Soil mites are the only tiny white bugs in the bunch that are actually highly beneficial. They break down and feed on organic matter in the soil and help with soil aeration. Some soil mites are predators that control pests such as thrips.
Soil mites should be left alone—they are good bugs.
Culprit #3: Root Aphids
What Do Aphids Look Like?
Root aphids, unlike aphids feeding on leaves , live in the soil. They are a common pest in greenhouses so they might have come with the potted plants. They are oval-shaped, woolly white in appearance and don’t move around as swiftly as foliar aphids. You need a hand lens to identify them.
Signs of Root Aphid Infestation
When root aphids feed on a plant, you’ll notice yellowing and/or curling of leaves, wilting of the plant, and stunted growth.
Culprit #4: Scale
What Do Scale Insects Look Like?
Scale insects, which can range from 1/8 to 1/16 inch in length, come in different colors, including white. They often come with contaminated soil and you’ll only notice them because at they form clusters that look like white bumps and not insects.
Signs of Scale Infestation
The signs of a scale infestation are yellowing and wilting of the leaves, curling of the edges, and eventually defoliation. If you inspect affected leaves with a hand lens, you might notice the puncture marks from their piercing and sucking.
Culprit #5: Fungus Gnats
What Do Fungus Gnats Look Like?
These small legless flies have white bodies and black heads. They are about the same size as fruit flies. Fungus gnats infest consistently moist potting soil, potting mix, and other container media. One telltale signs of their presence are slimy trails on the soil of potted plants that resemble trails from snails or slugs.
Signs of Fungus Gnat Infestation
Fungus gnats feed on plant roots, which causes yellowing of the leaves, leaf drop, and stunted growth.
How to Get Rid of Tiny White Bugs in Soil
After you have made sure that you are in fact dealing with a pest and not with beneficial soil mites, it is best to take a gradual approach.
- Start by isolating the infested plant so it does not move to other plants.
- Try to physically remove as many of the bugs as you can by scooping them up in the thin topmost layer of soil. Next, put the plant in the sink, a shower, or bathtub and thoroughly wash the leaves (including the undersides) and stems with water at room temperature (around 78 degrees F). Also, scrub the rim and outside of the pot—this flushes out a lot of bugs and their larvae.
- If the plant still struggles, do a soil drench with neem oil. Following label directions, dilute neem oil with water and pour it onto the potting soil. Even if you don’t see an infestation on the foliage, also spray it with neem oil while you’re at it.
The ultimate step if all else fails is transplanting the plant.
- Water the plant well to soften the soil, then lift it out of the old pot.
- Shake it very gently and run your fingers through the roots over a garbage can to remove as much soil as possible without damaging the roots.
- Next place the plant in a plastic tub in a sink or bathtub and wash off the soil. Don’t do it right in the sink or bathtub, or the soil may clog the drain.
- After you have removed as much soil as possible, transfer the plant to an old newspaper or large piece of cardboard. Drain water from the removed soil and dispose of the soil in the trash.
- Spray the roots with a neem oil solution (following the formula for a soil drench).
- Replant it with fresh sterilized potting mix in a new, sanitized pot.
Fungus Gnats. Missouri Botanical Garden.