Common Houseplant Pests – Effective Pest Control Tips
Houseplants spend most of their time indoors, where temperature, sunlight, and humidity might not be ideal. This makes them vulnerable to pests, which can easily get inside and multiply quickly since they lack natural predators indoors. There are many common houseplant pests.
To keep your indoor plants healthy, check them frequently for early signs of infestation. Catching pests early gives you the best chance to save your plants.
Common Houseplant Pests
- Aphids
Aphids are sap-sucking insects that produce sticky honeydew. They attack many plants, especially young, tender growth, causing damage and wilting. Their lifespan is short (usually 2–3 weeks), so populations can grow quickly.
How to Control Aphids
A strong spray of water can remove most aphids. Take the plant outside and hose it off (if temperatures aren’t too cold), or use a shower sprayer indoors. Neem oil or insecticidal soap sprays can also be effective.
- Mealybugs – Common Houseplant Pests
Mealybugs are soft-bodied insects that appear as white, cottony masses on plant leaves and stems. They may go unnoticed in early stages, but they’re easy to identify as adults, which are oval-shaped with a gray or white waxy coating.
When you spot adult mealybugs, they’ll likely lay many eggs. Mealybugs suck sap from plants and leave honeydew on surfaces, which attracts other insects and promotes sooty mold growth.
- Spider Mites
These tiny spider-like pests can eventually kill plants if left unchecked. They can be hard to detect until an infestation becomes severe, so regular plant monitoring is important. Calathea plants, in particular, are susceptible to spider mites.
How to Control Spider Mites
Remove any heavily infested parts of the plant. Rinse the plant thoroughly with a hose or cloth to remove as many pests as possible. Then, apply a pesticide mix such as 0.25 ml SB Revitalizer, 0.25 ml neem oil, 5–10 ml rubbing alcohol, and 0.5 liters of water. Spray this mixture on the plant weekly until pests and damage are no longer visible.
Alternatively, you can introduce natural predators like Phytoseiulus mites. These mites feed on all stages of spider mites and are less invasive. Sprinkle them on the infested plant for effective control.
Preventive Measures
Regularly inspect your plants to keep them pest-free.
Quarantine new plants as a precaution. You can also prevent infestations by spraying plants with a mix of 0.25 ml neem oil, 0.25 ml dishwashing liquid, and 0.5 liters of water or using an SB invigorator according to the product instructions.
- Scales
Scales are tiny insects that attach to plant stems and encase their bodies in hard, oval-shaped shells. Like mealybugs, they gradually drain sap from the plant, leaving it too weak to support its weight.
Scale infestations can be difficult to eradicate because pesticides often can’t penetrate their hard outer shells.
Try rubbing the scales off with your nails or using a soft brush. During the “crawler” stage, young scales can be sprayed with insecticidal soap when they move unprotected to find a new spot. This soap is effective on young crawlers but doesn’t work on protected adults.
- Fungus Gnats
Adult fungus gnats are delicate in appearance and are about 1/8-inch in length. Sometimes, they are seen running across or close to the soil’s surface beneath the houseplant. They are not very agile and are attracted by the light.
Adults do not take food from house plants but can annoy other people. When infested, they are usually observed in large numbers in windows around.
The white young (immature form) that fungus gnats carry are sleek black heads that reach as high as 1/4-inch. The larvae feed primarily on decaying organic matter or fungi growing in soil. The larvae of certain species also feed on the roots.
This is particularly harmful to young plants. The first sign of an infestation for established older plants will be that the plant begins to lose its normal appearance. The plant infested with enough pests could lose leaves due to the larvae feeding on the roots.
Indoors, fungus gnats are often found in potting soil high in organic matter, such as peat moss, especially when the soil is overwatered.
Control Measures
For plants that can tolerate it, allow the soil to dry out between waterings, as dry conditions kill larvae. Avoid letting water collect in saucers beneath pots, and turn outdoor saucers upside down to prevent rainwater collection.
Products containing Bacillus thuringiensis subspecies israelensis can be applied to houseplant soil for effective control.
- Thrips
Thrips are tiny, slender-winged insects that feed on leaves, flowers, and fruits, often favoring delicate, light-colored blooms. Commonly known as thunderflies, they appear black or wheat-colored and harm plants by sucking their juices.
Maintaining your garden and plants free of fallen leaves, dead or alive, can help prevent thrips from laying eggs.
If your garden is outside, introducing beneficial insects like bees, butterflies, or wasps can help control thrips as they prey on them without harming your plants. You can also wash affected plants and use pest removal techniques (sprays or repellents) to eliminate thrips.
Prevention
The best way to manage common houseplant pests is to prevent infestations before they start. Here are several precautions to help reduce the likelihood of pest problems:
- Provide plants with the ideal growing conditions they need to thrive. Stressed plants are more susceptible to pests.
- Check any new plants and their containers for signs of pests before bringing them indoors.
- Plants left outside during summer, especially those placed on the ground, may harbor insects that have entered through drainage holes. Check these plants carefully by removing them from their pots and inspecting the soil. Most pests are found on the outer parts of the root ball.
- Isolate new plants from existing houseplants for six weeks to ensure any pests are less likely to spread.
- Regularly inspect your plants, ideally once a week, for signs of pests or damage. Pay special attention to the undersides of leaves, as this is where pests often hide. A 10X magnifying lens can help detect small pests and their developmental stages. Infestations are much easier to control when caught early.
- When repotting, use commercially prepared potting rather than outdoor soil, which may contain pests.
- Cleaning smooth-leaved plants every 2 to 3 weeks enhances their appearance and helps prevent pests. Smaller plants can be turned upside down and gently swished in lukewarm water. To keep the soil in place, cover it with aluminum foil. Larger plants can be hosed down or wiped with a damp, soft cloth on both sides of the leaves. Alternatively, large plants can be rinsed with a mild shower.
- Since cut flowers from the garden may carry pests, keep them away from your houseplants.
- Common houseplant pests can enter homes from outside, so ensure that doors and screens fit properly to minimize their entry points.
Non-Chemical Control
The first step in pest control is to isolate the affected plant. Keep it away from other plants until the pest is completely eradicated, which could take a few weeks or longer.
Various non-chemical options should be considered for effective pest control in houseplants, though they may require persistence. Each solution usually works independently, but with patience, these methods can provide adequate control.
Remove and discard the affected parts if only part of the plant is affected, such as with leafminers. If the root system is infected, take cuttings to start a new plant and use fresh, clean potting soil. Early infestations are often managed by handpicking pests.
For houseplant insects like aphids and mealybugs, use a cotton swab dipped in rubbing alcohol to remove them. Scale insects may need to be carefully removed with a fingernail.
Spraying your plant with water can help remove many pests—spray the entire plant surface. Repeated water sprays can be effective for controlling spider mites.
Applying insecticidal soap is often an effective way to manage pests in the early stages. Insecticidal soaps work only when in direct contact with the insects, as they lose effectiveness once the solution dries.
They are particularly effective against soft-bodied insects and pests like mealybugs, aphids, immature scale insects (crawlers), thrips, spider mites, and whiteflies. Multiple treatments are usually required because some pests may be hidden or in the egg stage.
If the plant is severely damaged and no longer worth saving, the simplest solution may be to dispose of both the plant and the soil and start fresh with a new plant.
Chemical Control
If other control methods aren’t working and the plant is worth saving, a stronger pesticide may be necessary.
Before choosing a pesticide, it’s essential to accurately identify the pest, as a single pesticide typically won’t work against all pests.
Certain pesticides target specific pests or stages of a pet’s life cycle. Also, multiple pesticide applications may be needed, so if possible, alternate between different pesticides to reduce the risk of pests developing resistance.
Pesticides for houseplants can be found at garden centers and farm supply stores, though only a few are specifically labeled for indoor use.
Always check the label to confirm it’s safe for indoor use. Treat your plants outside and wait until the pesticide is fully dry before bringing them back indoors. Spraying outdoors also prevents pesticide residue from landing on furniture, drapes, or carpets.
Typically, a pesticide label will list recommended plants and plants that may be sensitive to the product. Signs of pesticide damage on plants can include distorted buds or leaves, discoloration, yellowing of flowers or leaves, leaf burn around the edges, or complete leaf burn. If damage occurs, symptoms usually appear within five to ten days.
Most of the time, this damage is not fatal to the plant.
Before purchasing and using any pesticide, read and carefully follow the instructions on the label.
Help with Common Houseplant Pest Prevention
Common houseplant pests prevention is often thought of as weekly applications of chemical or natural repellents. However, a crucial element is often overlooked—using well-draining potting mixes. Properly draining soil helps support the overall health of your plants.
Another effective preventative measure is using pebble ground cover. Pebbles work best with well-draining potting mixes, as they help retain moisture when combined with denser soils.
FAQ
What are those tiny brown bugs on my houseplants?
The brown soft scale is a common insect pest found on many indoor plants, such as Ficus, Schefflera, English Ivy, and citrus. As brown soft scales feed, they produce a sticky, shiny honeydew that can coat the leaves.
Are there any common indoor plant bugs?
The most common household plant pests are scale insects, aphids, mealybugs, thrips, whiteflies, spider mites, springtails, and fungus gnats. Some insects, like thrips, are tiny and difficult to detect, and infestations are often more easily identified by the damage they cause.
How can I identify soil mites?
Identifying soil mites can be tricky as they’re often small and hard to spot. However, if you closely examine the soil, you may notice tiny dots moving around. If they’re not ticks or spiders, they’re likely soil mites. They may appear white, brown, or in other colors.
What kinds of bugs can be found in houseplant soil?
Common bugs in houseplant soil include slugs, sowbugs, earwigs, fungus gnats, and ants. When dealing with small container plants, gently remove the plant from the pot and examine the soil.
Generally, slugs, sowbugs, and ants are visible on the soil surface or near drainage holes. Remove them using your fingers or a stick.