Aphids, spider mites, fungus gnats and what really helps
Eventually, every houseplant gets affected. Tiny flies in the soil, sticky leaves, fine cobwebs – pests are part of plant life. But you can get rid of them.
Plant pests are annoying, but no reason to panic. Most can be controlled with simple methods if detected early enough. It's important to regularly check your plants – the upper and lower sides of the leaves, and the soil.
Fungus gnats - The small black flies
The most common pest of houseplants: small black flies that rise from the soil. The flies themselves are harmless, but their larvae feed on the delicate roots.
Identification: Small black flies that rise from the soil when watering.
Cause: Soil that is too moist. The larvae need moisture.
Control: Water less frequently and allow the soil to dry out between waterings. Yellow sticky traps catch the adult flies. Nematodes (from garden centers) combat the larvae in the soil. A layer of sand or quartz gravel on the soil prevents egg-laying.
Spider mites - The invisible danger
Tiny arachnids that suck sap from the undersides of leaves. They love dry, warm air – that's why they are most common in winter when the heating is on.
Identification: Fine spider webs on leaf stalks and leaf axils. Small light-colored spots on the leaves (feeding marks). Leaves turn yellow and fall off.
Control: Increase humidity (spray plants regularly). Rinse affected leaves under the shower. In case of severe infestation: Spray neem oil or rapeseed oil preparations on the undersides of the leaves.
aphids
Small green, black, or white insects that live in colonies on young shoots and buds. They suck plant sap and excrete sticky honeydew.
Identifying signs: Sticky leaves, deformed shoot tips, visible aphid colonies.
Control: Rinse the plant under the shower (most aphids will fall off). Spray a solution of dish soap and water (a squirt of dish soap in water) onto the leaves. For severe infestations: use neem oil spray.
Scale insects and woolly aphids
Scale insects look like small brown shields on stems and leaves. Woolly aphids (mealybugs) can be identified by white, cottony nests in leaf axils.
Identification: Brown scales (scale insects) or white cotton balls (mealybugs). Sticky deposits.
Control: Dab individual insects with a cotton swab soaked in alcohol. Spray with neem oil. In case of severe infestation: Use systemic insecticides (insert sticks into the soil). Scale insects are persistent – patience and repeated treatment are necessary.
Thrips
Tiny, elongated insects that move quickly. They leave silvery streaks on the leaves and black droppings.
Identification: Silvery streaks and spots on leaves, black dots (feces).
Control: Blue sticky traps (thrips are attracted to blue). Shower the plant. Neem oil or predatory mites (biological control).
Prevention:
Always quarantine new plants for two weeks before joining the others.
Regularly check the undersides of the leaves - that's where most pests hide.
Healthy, vigorous plants are less frequently infested. Good care is the best protection against pests.
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Controlled quality, care tips included.
Frequently Asked Questions about Plant Pests
Yes, neem oil is one of the most effective natural remedies. It works against aphids, spider mites, thrips, and mealybugs. Important: Spray evenly on both the upper and lower sides of the leaves. Repeat several times at weekly intervals, as it does not kill the eggs.
Yes, most pests spread quickly to neighboring plants. Therefore, isolate and treat infested plants immediately. That is the most important first step.
If the infestation persists despite several weeks of treatment and the plant is severely weakened, it is sometimes better to discard it – before the pests spread to healthy plants. This is not a defeat, but rather plant protection for the rest of the collection.
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