Do ants mean I have aphids?

Yes, ants often farm aphids to collect the sweet honeydew they produce, so seeing a lot of ants on your plant is a strong sign of an aphid problem.

Will aphids kill my plant?

While they rarely kill a healthy, mature plant, they can severely weaken it and stunt its growth, making it more susceptible to other diseases.

Can I just wash them off?

For small infestations, a strong spray of water is often enough to control them, but you must be consistent and hit the undersides of the leaves.

Aphids

Symptoms by part

Leaves

Leaves may look yellow, curled, or distorted, and you might see a sticky substance called honeydew or a black sooty mold growing on the surface.

Stems

Clusters of small green, black, or pink insects gather on new, tender growth, often causing the stem to bend or stop growing.

Flowers

Buds may fail to open properly or appear deformed, and the flowers themselves may be covered in sticky honeydew.

Causes

Excessive nitrogen fertilizer which encourages soft, succulent growth that aphids love.
Lack of natural predators like ladybugs or lacewings in the garden.
High humidity and warm temperatures during the growing season.

Could be confused with

Whiteflies · Whiteflies are tiny white winged insects that fly up in a cloud when you disturb the plant, whereas aphids are usually wingless and stay put.
Scale insects · Scale insects look like small, immobile bumps or shells attached to the plant, while aphids are soft and move slowly.

Treatment

1. Use a strong stream of water from a hose to physically blast the aphids off the leaves and stems.
2. Prune away heavily infested tips or leaves to reduce the population quickly.
3. Apply fatty acids as a contact spray directly onto the insects, follow the label.

Without chemicals

Prune off the most heavily infested plant parts.
Introduce or encourage natural predators like ladybugs and lacewings.
Use reflective mulches to confuse the insects.

Chemical options

Fatty acids, spray directly on the insects to disrupt their cell membranes, follow the label.
Pyrethrins, use as a contact spray on the insects, follow the label.

Preventing it

Avoid over fertilizing with nitrogen to prevent excessive soft growth.
Plant flowers like marigolds or dill to attract beneficial insects that eat aphids.
Check the undersides of leaves regularly for early signs of infestation.

Season

The warm growing season.

Spread risk

High

Severity

Moderate

When to act

Act as soon as you see the first clusters of insects to prevent a full outbreak. If the plant is severely stunted or covered in mold, it may be best to remove it to protect the rest of your collection.

Think it's Aphids?

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Questions people ask

Do ants mean I have aphids?: Yes, ants often farm aphids to collect the sweet honeydew they produce, so seeing a lot of ants on your plant is a strong sign of an aphid problem.
Will aphids kill my plant?: While they rarely kill a healthy, mature plant, they can severely weaken it and stunt its growth, making it more susceptible to other diseases.
Can I just wash them off?: For small infestations, a strong spray of water is often enough to control them, but you must be consistent and hit the undersides of the leaves.

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This guide was generated with AI and is general information, not horticultural advice. Read about how we build these guides.