Mealybugs and scale insects are small sap-sucking insects that attach themselves to plants and draw out their sap. They’re common in Morocco, on houseplants as well as in gardens, and thrive in heat and dry air. They don’t kill a plant within days, but weaken it little by little. The good news: with regular treatment, you can get rid of them without chemicals.
Recognising them
Mealybugs
These are small white, cottony clumps, like flour or cotton wool, lodged in leaf joints, under leaves, along the veins and sometimes on the roots. They’re often found on Monsteras, Ficus, succulents and cacti.
Armoured scale
These are small brown, beige or grey shells, flat or domed, stuck to stems and under leaves. They’re often mistaken for part of the plant. Scratch with a fingernail: if the shell comes off, it’s a scale insect.
The tell-tale signs
- Sticky leaves and floor: this is honeydew, the sugar excreted by the insects.
- A black dust on the leaves: sooty mould, a fungus that grows on the honeydew.
- Yellowing leaves and a plant that has stopped growing.
Getting rid of them, step by step
- Isolate the plant: these insects easily spread from one plant to another.
- Remove them by hand: a cotton bud dipped in soapy water or 70% alcohol for mealybugs; a fingernail or an old toothbrush for armoured scale. Cut back heavily infested parts.
- Clean the foliage, top and underside, with cleaning gloves or a damp cloth, and rinse the plant in the shower if its size allows.
- Spray ready-to-use black soap over the whole plant, concentrating on the undersides of leaves and the leaf joints. Soap works on contact: it has to touch the insects.
- Repeat every five to seven days for at least a month: the protected eggs hatch in several waves.
Preventing them
- Inspect every new plant before putting it with the others.
- Dust the leaves regularly: you’ll spot the first insects early.
- Avoid too much nitrogen fertiliser, which produces the tender shoots they love.
Frequently asked questions
Are mealybugs and scale dangerous to people or pets?
No, they only attack plants.
Should I throw the plant away?
Rarely. Only a heavily infested plant that’s already weakened is sometimes no longer worth the fight. If in doubt, ask us.
Need an opinion?
Send a photo of your plant to our Plant Doctor: the whole plant, a close-up of a leaf (top and underside) and the surface of the soil. The diagnosis is free, and you can also drop by the studio at 6 Rue Zemmour, Aviation district, Rabat, Tuesday to Saturday, 10am to 6pm.
