Aphids: how to get rid of them gently, or with an approved product

In brief: A small colony of aphids can simply be washed off with a sharp jet of water or snipped off together with the infested tips, and ladybirds, lacewings and hoverflies will deal with the rest. For a heavy infestation, nettle infusion or a product with potassium salts of fatty acids helps. Use an insecticide last, only one approved for the crop in question, and never during flowering.

Aphids always turn up. In spring they colonise the tips of roses and currants, in June broad beans and viburnums, in summer peppers, and in autumn they move onto houseplants. On their own they will not destroy a plant overnight, but they multiply so fast that a week of waiting can turn a few individuals into coated shoots and curled leaves.

The good news is that most infestations can be solved without chemicals. Here is the procedure from the gentlest intervention to an approved spray, including what definitely not to use against aphids.

How to recognise aphids and why there are suddenly so many

Aphids are small, soft insects, usually 1–4 mm long, green, black, grey or pinkish. They sit in dense colonies on young shoots, on the undersides of leaves and in buds. They suck the sap; the leaves curl and turn yellow, shoots become stunted and flowers do not open.

They also give themselves away by what can be seen from a distance: sticky honeydew on the leaves beneath a colony, the black coating of sooty mould that grows on the honeydew, and ants running up and down the plant. Ants protect aphids from predators because they feed on honeydew.

The speed of reproduction is the main problem. In summer the females give birth to live young without fertilisation, and a new generation is adult in roughly 1–2 weeks. When a colony becomes crowded, winged aphids appear and fly to other plants. Aphids also transmit viral diseases, for example cucumber and pepper mosaics.

The most common aphids in the garden

If you are not sure whether you are dealing with aphids, whiteflies or spider mites, the visual guide to plant diseases and pests can help.

What to do straight away: a procedure from the gentlest intervention

1. Check the extent. Go over the tips and the undersides of the leaves. A few colonies on one bush are no reason to spray; just keep an eye on them.
2. Remove the hot spots. Snip off heavily coated tips and throw them in the bin, not on the compost. Wipe off individual colonies with a gloved finger.
3. Spray with water. Wash the aphids off the shoots with a sharp jet from a hose or sprayer, preferably in the morning so that the leaves dry by evening. Repeat every 2–3 days for 1–2 weeks. Only some of the fallen aphids return to the plant.
4. Cut off the ants. Put a sticky band on the trunks of trees and shrubs, but apply the glue to a strip of paper or film, not directly on the bark. Without ants, predators can deal with the colonies. More in the article How to get rid of ants.
5. Give the predators room. When you see ladybird or hoverfly larvae on a colony, do not spray. Within a week the problem is usually gone.
6. Spray only when they have multiplied excessively. When aphids occupy more than 10% of shoots and the colonies keep growing even after spraying with water, use nettle infusion or a fatty-acid product. An approved insecticide only as the last step.

Natural enemies of aphids and how to attract them

In a garden without blanket spraying, more aphid predators live than you might think. Each of them works differently:

• Ladybirds – adults and larvae eat aphids by the hundred. The larvae look like small grey-black "alligators" with yellow spots; do not confuse them with a pest. The difference between our native and the Asian ladybird is covered in the article Ladybirds in the garden.
• Lacewings – their larvae suck dry aphids and the eggs of other pests. Adults feed on pollen and nectar.
• Hoverflies – wasp-like flies whose legless larvae hunt aphids right in the colonies.
• Parasitic wasps – lay their eggs in aphids. A parasitised aphid hardens into a swollen golden-brown "mummy". They can be bought for greenhouses (Aphidius colemani).
• Earwigs and birds – earwigs at night on trees, tits when feeding their chicks.

You attract predators with flowering plants with small flowers (dill, phacelia, calendula, yarrow), with overwintering places in the form of uncleared stems, and above all by not spraying broad-spectrum insecticides. These kill the predators along with the aphids, and because aphids recover faster, the next wave is worse. The whole approach is described step by step in the guide to biological plant protection.

Nettle infusion and other natural sprays

Since 2017 nettle has been approved in the EU as a basic substance for plant protection, and the register of ÚKZÚZ (the Central Institute for Supervising and Testing in Agriculture) lists it, among other things, against aphids on cabbage, lettuce, beans, potatoes, fruit trees, currants and roses. The approved method differs from nettle slurry, which is used for feeding:

1. Pick young nettles that are not yet flowering and chop them up.
2. Use 75 g of fresh leaves per 1 litre of water, or 15 g of dried ones. For an ordinary 5-litre sprayer, therefore, less than a litre of infusion is enough.
3. Leave to steep for 3–4 days at room temperature of around 20 °C, stirring once a day.
4. Strain and dilute with five times the amount of water (1 part infusion to 5 parts water).
5. Spray directly onto the colonies, not forgetting the undersides of leaves. Repeat after 7–15 days, at most 5 times per season.

Prepare the infusion in a clean container with a lid and use it fresh. Do not spray it on vegetables just before harvest, and if you do, wash the harvest thoroughly.

Potassium soap and rapeseed oil

Garden centres sell registered products with potassium salts of fatty acids. They dissolve the protective coating of aphids and act only on those you hit, which is why thorough coverage is important. The concentration, number of treatments and interval are set by the label of the particular product (concentrates are usually diluted to around 2%). Products with rapeseed oil work similarly, alone or with natural pyrethrins. Potassium soaps and oils are gentler on predators than synthetic insecticides, but products with pyrethrins also hit beneficial insects. All are toxic to aquatic organisms, so do not spray them near a pond.

Home recipes not to use against aphids

• Washing-up liquid – contains degreasers and fragrances that burn leaves, especially in the sun. It is not the same as the potassium soap in a registered product.
• Thinners, alcohol, paraffin, petrol – they burn the plant before the aphids and contaminate the soil. Never.
• Infusion of cigarettes or tobacco – nicotine is banned as an insecticide in the EU. It is acutely poisonous to people, animals and bees and remains on vegetables.
• Vinegar and salt – they damage the leaves and the soil and do not reliably act on aphids.

Approved products: what you may use against aphids

You may use a plant protection product only on the crops and pests for which it is authorised in the ÚKZÚZ register and on the label. For the products we have on offer, the following applies according to the register and labels (but always read the label of the particular pack, as authorisations change):

Both products are pyrethroids. They act quickly, but they also kill ladybirds and lacewings, and deltamethrin is highly toxic to bees. Some populations of peach-potato aphid are also resistant to pyrethroids. So treat them as a last resort, not as the first step.

Karate Zeon 5 CS is authorised for non-professional users only on tomatoes against the Colorado potato beetle and the greenhouse whitefly. Do not use it against aphids or on houseplants.

How to spray safely

• Spray in the evening after bees have stopped flying, in still air and not before rain. Never on flowering plants or on flowering undergrowth beneath trees.
• Keep to the dose and the pre-harvest interval, that is, the number of days between the last spray and harvest.
• Wear gloves; do not pour the rest of the spray into a drain or near water, and rinse the sprayer out over the treated area.
• Do not mix products with each other unless the label expressly allows it.

How to read a label and choose between contact and systemic products is explained in the article Familiar pests: whiteflies, aphids and spider mites.

Aphids on trees, vegetables, herbs and indoors

Fruit trees and bushes

Aphids overwinter as eggs on branches. In spring, before bud break, registered oil products against overwintering stages are used against them. Once the leaves have rolled up, a spray does not reach the aphids, so intervene as soon as you see the first colonies on the opening shoots. Put sticky bands against ants on the trunk in spring.

Vegetables

On broad beans, pinch out the tops as soon as the lower pods have set. The black bean aphid sits right there, and it does the plant no harm. Protect brassicas and young sowings with fleece straight after planting; it prevents an invasion of winged aphids and flea beetles. On tomatoes and peppers in a greenhouse, check mainly the undersides of the leaves.

Herbs

Herbs are eaten fresh, so for them only a water jet, snipping off infested shoots and nettle infusion. An insecticide only if the register expressly authorises it on culinary herbs, and observing the pre-harvest interval.

Houseplants

Separate an infested plant from the others straight away. Rinse it with lukewarm water, covering the compost with film. Wipe off colonies in the leaf axils with a cotton bud. Repeat every 3–4 days for as long as aphids keep appearing. Indoors they have no natural enemies, so you need to persevere for at least 2–3 weeks.

Why aphids come back

• Overfeeding with nitrogen – soft, fast-growing shoots are the best food for aphids. Feed less, and preferably organically.
• Drought stress – a weakened plant attracts aphids more. Water generously and less often.
• Ants – as long as they guard the colonies, predators have no chance.
• Blanket insecticides – they destroy the predators, and aphids return sooner than they do.
• Winter hosts – the black bean aphid overwinters on spindle and viburnum. So check viburnums first in spring.

Frequently asked questions

What is the best thing to spray aphids with?

At the start a sharp jet of water is enough. For a heavy infestation, nettle infusion following the approved method or a product with potassium salts of fatty acids. A synthetic insecticide last, and only one approved for your crop.

How can I get rid of aphids naturally?

Combine snipping off hot spots, spraying with water every 2–3 days and encouraging predators. Ladybirds, lacewings and hoverflies can deal with most colonies, provided they are not destroyed by spraying and not hindered by ants.

Does washing-up liquid or soapy water help against aphids?

We do not recommend washing-up liquid; its degreasers and fragrances burn the leaves. Registered potassium soaps, that is, products with potassium salts of fatty acids at the prescribed concentration, are effective and gentle on plants.

How do I get rid of aphids on houseplants?

Isolate the plant, rinse it with lukewarm water with the compost covered, and wipe off the remaining colonies. Repeat every 3–4 days for at least 2–3 weeks; indoors aphids multiply even in winter.

Why are there ants on a plant with aphids?

Ants collect the sweet honeydew that aphids excrete and in return protect them from predators. A sticky band on the trunk or stem often solves the aphid problem by itself by breaking up this "cooperation".

How long after spraying can I harvest?

According to the pre-harvest interval on the label of the particular product and crop. For Fast M it is 14 days on tomato and potatoes, and 28 days on apple trees and stone fruit.

Recommended products

• Prost Fast M insecticide, 500 ml – a ready-to-use spray for spot treatment, authorised on ornamental plants, tomatoes, potatoes and fruit trees.
• Sanium Ultra insecticide – a ready-to-use spray with deltamethrin; use only on the crops stated on the label, outside flowering and bee flight.
• Chemstopecofix 250 ml – a non-drying glue for sticky bands against ants, which protect aphids.
• SPRIT sprayer 750 ml – for water jets and nettle infusion on houseplants and herbs.
• AquaKing pressure sprayer 3 l – for bushes and smaller trees where a hand sprayer is not enough.
• White fleece 1.6 × 5 m – a barrier against invasion by aphids and flea beetles on young vegetables.

Sources

• Register of plant protection products (ÚKZÚZ): authorised uses of Fast M, Sanium Ultra, Karate Zeon 5 CS and the basic substance nettle
• Commission Implementing Regulation (EU) 2017/419 on the approval of the basic substance Urtica spp. (EUR-Lex)
• Aphids (Royal Horticultural Society)

Updated: 27 September 2026