How to get rid of aphids

The complete guide

Oleander aphid

Difficulty Medium

Frequency Medium

Reproductive rate Up to 500x

Lifecycle Up to 4 months

Aphids are insects that damage plants by feeding on their sap. They gather in colonies of several dozen individuals on shoots or flowers. A large enough population can cause growth to stall in infested plants.

Vegetable plants

Ornamental plants

Identifying aphids

Aphid colonies are very easy to spot. The clustered individuals are usually pear-shaped, and their color varies depending on the species and the host plant. These insects also produce honeydew, a sticky substance visible on the leaves. A black mold called sooty mold can develop on this honeydew.

Early infestation

Presence of shed skins on the foliage
Presence of a few insects under the leaves
Sticky substance on leaves and stems

Advanced infestation

Dense insect colonies on the shoots or flowers
Deformation of shoots or flower buds
Slowed or stunted growth
Black mold on leaves and stems

Treatment options

Indoor plants

Small greenhouses

You will need :

Scissors / Pruners
Plastic bags

Natural predators :

Green lacewings

How to treat aphids?

The most effective and safe strategy is to dislodge the majority of nymphs and adult aphids using a strong water jet and introduce green lacewings to detect and eliminate any remaining individuals.

1

Preparation

Cutting a damaged leaf in a tropical plant

Cut off affected shoots

If possible, cut off the new shoots where aphids are clustered.

Removing debris from the soil of a tropical plant

Remove debris

Remove dead leaves and other debris that may interfere with the treatment.

Wrap the pot

Wrap the pot in a plastic bag to protect the root ball during the treatment.

2

Cleaning

Prepare a workspace

Prepare a workspace that can get wet; ideally outside, in the sink or in the bathtub.

Adjust the water

Use the strongest jet of water possible without damaging the plant (hose, faucet, showerhead, etc.).

Cleaning a tropical plant with a powerful water jet

Wash the leaves and stems

Generously spray all leaves and stems. Cover all angles in several passes.

3

Drying

Let the plant dry

Wait for the leaves to be completely dry before introducing predators.

4

First introduction

Installation of green lacewing strips in the foliage of a tropical plant

Introduce the lacewings

Install the lacewing strips in the plant’s foliage.

5

Second introduction

Repeat the introduction

Wait three weeks and repeat the same introduction.

A few important points

Natural predators are particularly effective at detecting any remaining aphids once their population has been reduced. The more thorough the initial cleaning, the higher the chances of success.
Since a single aphid can restart an infestation in just a few days, treatment must be carried out completely and without interruption.

Once the treatment is complete

Inspect the plants regularly for at least eight weeks. If new signs of aphids appear, repeat the cleaning of affected plants every five days. Otherwise, you can consider your treatment successful. For added caution, feel free to carry out a few additional introductions of green lacewings.

Do I absolutely need to treat all my plants?

Aphids spread quickly, and the absence of symptoms does not mean the plants are healthy. It is therefore strongly recommended to treat all visibly affected plants as well as those nearby.

What should I do if I cannot wash a plant with a water jet?

If washing the plant with a water jet is not possible, you will need to reduce the aphid population in another way. A common alternative is the black soap foliar treatment. Spray it very generously to saturate all surfaces of the plant, without exception.

Do I need to repeat cleaning before each introduction?

Cleaning is always necessary before the first introduction. If the initial infestation was severe or many insects are still visible at the time of subsequent introductions, it is preferable to carry out another pre-introduction cleaning. Conversely, it is no longer necessary once the infestation appears to be under control.

Is it necessary to replace the substrate to treat aphids?

Nymphs and adult aphids remain on the foliage. Not only is replacing the substrate unnecessary, but it also causes additional stress that could further weaken the plant.