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How to control pests and diseases on house plants

This is a short guide to help you idenitify and control most common pest attacks and diseases on house plants.

This is a short guide to help you idenitify and control most common pest attacks and diseases on house plants.

Pest Problems and Solutions



Sap-sucking insects that are usually green, but can be coloured orange, grey or black, too. They attack all soft, vulnerable parts of the plant, weakening it. 



These resemble tiny brown pads or discs that cling to the undersides of leaves and in a bad attack, will also deposit a sticky substance. Scale needs to first be removed as much as possible with a piece of damp cotton wool or damp cotton buds, and then treated with Provado Ultimate Bug Killer Aerosol.

Mealy bug

This manifests itself as specks of white cotton wool on stems and under leaves but these white specks are pests that can defoliate an indoor plant if left unchecked. Wipe off with a damp cloth or damp cotton buds as much as possible, then spray with Baby Bio House Plant Insecticide.

Red spider mite

These sap-sucking pests are a familiar sight on houseplants that inhabit hot, dry rooms. Regular water-spraying with a fine mister will help keep them at bay. The spiders themselves are barely visible; small, numerous yellow blotches on the leaves are a more reliable symptom, and there are sometimes small white cobwebs between leaf and stem. Spray with Provado Ultimate Bug Killer Aerosol.  

Vine weevil

If a plant wilts or dies suddenly, vine weevil is likely to be the culprit. It comes with the compost in the form of small, cream grubs that eat absolutely everything beneath the compost surface, causing the plant itself to collapse for no apparent reason. Any treatment is likely to be too late.
To try and prevent a reoccurrence, buy houseplants from reputable suppliers and check the leaves before buying for any holes in leaves, which will have been made by the adult beetles. Use Provado Vine Weevil Killer 2 to help keep vine weevil under control.


Yellow, falling leaves can be a sign that whitefly is present. Check the undersides for a mass of small white flies which are difficult to eradicate. Remove all badly affected leaves as well as fallen foliage to help eliminate this pest and treat with Provado Vine Weevil Killer 2. In addition, try using a Greenhouse Fly Catcher.

Indoor Plant Diseases - Problems and Solutions

Most indoor plant diseases are caused by poor hygiene and cultivation. As soon as you spot a problem, remove the affected parts of the plant, and try the solutions mentioned below.

Powdery mildew

An unsightly fungal disease which appears on the plant’s leaves, coating them with a white powdery deposit. It is a sign of poor ventilation, so this needs to be improved to prevent further attacks. Remove all leaves showing signs of attack.

Leaf spot

As the name suggests, brown spots appear on the leaves and, if left untreated, are likely to merge into one and kill the leaf. All infected leaves need to be removed and destroyed. The brown spots are moist and so drying out the plant will be helpful: avoid misting for a month or two, and keep the compost barely moist.

Sooty mould

This is a black fungus that appears on foliage and can damage the plant's health by cutting out light to the leaves. It is caused by both the honeydew deposited by aphids as well as mealybugs. Remove the mould by wiping with a damp cloth and rinsing afterward. Treat pests that produce honeydew with Provado Ultimate Bug Killer Aerosol or Baby Bio House Plant Insecticide.