Aphids come in many colours, shapes and sizes, often with particular host plants. Greenfly and blackfly are the most familiar aphids but there are also yellow, red, orange and brown types. While most aphids are found in the garden, some end up our homes and target our house plants. Without the natural predators such as birds and ladybirds, they breed rapidly. They can quickly build up into large infestations if not dealt with promptly.
Symptoms of aphid damage
Aphids suck sap from plants and the excess sap is excreted as honeydew. This sticky residue falls on to the leaves, leading to black sooty mould, which inhibits photosynthesis and deprives the plant of energy. This not only looks unsightly but can weaken the plant, distort growth and spread viral diseases between plants. If not dealt with, severe aphid infestations can even kill your house plants.
How to deal with aphids on house plants
Aphids enter the home through open windows and doors, on cut flowers or on newly purchased house plants. A single female can produce thousands of young parthenogenetically (without mating) so it’s important to be vigilant and inspect your house plants regularly. Act quickly if you spot even just one.
You can remove aphids by hand, by using a spray or jet of water, or by placing plants outside to expose the aphids to predators.
More on controlling aphids:
Find detailed methods of controlling aphids on house plants, below.
You Will Need
- Spray bottle full of water
- Insecticides (chemical or organic)
Inspect plants for aphids, paying particular attention to the undersides of leaves and the stem tips. Also look for tiny, white shed skins and for stickiness on the leaves or surrounding surfaces, caused by aphids expelling excess sap.
If you find any aphids, quickly isolate the affected plant from its neighbours. Use a spray bottle filled with water to blast away any visible aphids, or rub them off using your fingers.
Keep a close watch for further outbreaks. If aphids reappear, consider spraying with an insecticide for indoor plants, following the pack instructions. Always take house plants outside when applying chemicals.
If you prefer not to use chemicals or if the infestation is severe, take cuttings and dispose of the original plant. Choose stems or leaves that are unaffected, snip them off with clean secateurs and wash off any aphids.
Look for signs of viral infection on any plants with aphids. Symptoms vary, but often include leaf discoloration, yellowing and distortion. There is no cure, so dispose of affected plants – don’t take cuttings or compost the plants.
Hang yellow sticky traps around your house plants and check them regularly. They’re a good early warning system, as you’ll see aphids in the traps if there’s an infestation. The traps will also capture other common flying pests, including whitefly and fungus gnats. If you don’t like the look of these traps, try growing sticky carnivorous sundews (Drosera) to catch the flies instead.