Treat indoor infestations early to save your plants
Sap-sucking mealybugs can be a problem all year on indoor-grown plants. So check your houseplants, cacti, orchids and glasshouse vines and fruit trees for these greyish, scale insects up to 4mm long, and for their eggs covered in white, fluffy pouches.
They tend to gather on leaf undersides, in leaf joints and around growth points, feeding on sap sucked from their host. This weakens the plant, causing stunted or deformed growth and yellowing or dropped leaves. The bugs also secrete honeydew, which can be colonised by black, sooty moulds.
To combat infestations organically, pick off as many mealybugs as possible, cut off badly infested stems and shoots if it doesn’t severely damage or disfigure the plant and clear away debris from around the base. Also check for mealybugs lurking in the soil, nearby crevices, the pot rim and tray.
Next, use an organic fatty acid or insecticidal soap, such as Doff Universal Bug Killer (£2.99 for 1 litre, from Homebase, 0345 077 8888; www.homebase.co.uk) – or diluted washing-up liquid. Spray the plant or wash leaves thoroughly with the solution. Alternatively, try Neem Oil (£6.98 for 30ml from The Neem Team, 01633 263567; theneemteam.co.uk.
In greenhouses, where temperatures can reach 20C (68F) for a few hours a day, use the ladybird predator Cryptolaemus montrouzieri (£10.96 for 10 larvae from Defenders, 01233 813130; www. defenders.co.uk).
Organic sprays are kinder to the environment