Clusters on soft growth
Look closely at shoot tips, stems and leaf undersides for pear-shaped insects. Colours vary from green and black to grey, pink or waxy white.
A few aphids are normal and feed ladybirds, hoverfly larvae, lacewings and birds. The useful question is not “how do I sterilise the plant?” but “is this colony distorting vulnerable new growth faster than predators are finding it?”
Start with the quick check ↓Quick check
What to inspect now
Turn over young leaves and inspect soft shoot tips. Aphids cluster together, move slowly and may leave sticky honeydew or white cast skins.
- Main timing
- Most noticeable outdoors in spring and summer; possible all year under cover.
- Plants affected
- Beans, peas, lettuce, brassicas, tomatoes, peppers and many other vegetables.
Identification
Signs that narrow it down
Curling or distortion
Heavy feeding on young tissue can curl leaves and check growth. Open a curled leaf before diagnosing—the aphids may be hidden inside.
Sticky leaves
Honeydew can make foliage tacky and later support dark sooty mould. Ants running up stems often indicate that honeydew-producing insects are present.
If you confirm it
Useful action, in order
Start with the least disruptive step that protects the crop. The presence of a pest does not automatically justify treatment.
- 1
Wait and watch small colonies
Check for ladybirds, hoverfly larvae, lacewing larvae and swollen, bronze aphid “mummies” parasitised by tiny wasps. Natural enemies often catch up.
- 2
Remove concentrated colonies
Rub aphids from robust shoot tips with gloved fingers, prune a badly infested tip where that will not harm the crop, or dislodge them with a firm water jet.
- 3
Protect young crops selectively
Fine insect mesh can reduce arrivals on vulnerable vegetables, but seal the edges and remember that mesh also excludes predators and pollinators.
Next crop
Reduce the chance of a repeat
Avoid excess soft growth
Overfeeding with nitrogen produces lush shoots that can support rapid aphid growth. Feed vegetables for steady, balanced growth.
Grow flowers for predators
A long season of small, open flowers supports hoverflies and other beneficial insects. Keep some undisturbed habitat nearby.
Inspect transplants
Check bought plants and home-raised seedlings before placing them in a greenhouse or beside clean crops.
Common questions
Practical answers
Will aphids kill my vegetable plants?
Small colonies usually cause limited damage. Seedlings and heavily infested soft growth are more vulnerable, so judge the plant’s growth and the size of the colony rather than reacting to one insect.
Should I spray washing-up liquid on aphids?
Household detergents are not formulated or approved as plant-protection products and can scorch foliage. Prefer physical removal, tolerance and established garden controls used exactly as labelled.
Why are ants walking over the aphids?
Ants collect sugary honeydew and may protect aphid colonies from predators. Their presence is a useful clue, but controlling ants alone does not remove the aphids.
Sources and scope
Evidence behind this guide
SowNext summarises identification, timing and lower-impact management for UK home food growing. Local populations and protected conditions can differ, so confirm the organism before acting.