Managing pests organically with neem and soap sprays

Almost every balcony gets pests at some point. The ones we meet most often are soft-bodied sap suckers: aphids, whitefly, spider mites and mealybug, with caterpillars on curry leaf and hibiscus. None of them needs a harsh chemical on a home balcony. Caught early, they clear up with a hose, your fingers and a simple neem or soap spray. What matters is spotting them early and repeating the treatment until the next generation has hatched and gone as well.

Know what you are dealing with

Aphids are tiny green, black or yellow insects crowded on new shoots and buds, which curl and twist as they feed. Whitefly rise from the underside of leaves in a small white cloud when you brush the plant. Spider mites are almost too small to see; look instead for fine speckling on the leaves, a dull, dusty look and, in bad cases, fine webbing in the leaf joints. They love hot, dry spells. Mealybug is white, cottony fluff in the joints and under leaves. All four leave sticky honeydew, and ants climbing the stems often point you straight to them.

First steps, without a spray

Move the affected plant away from the others. Take it to the balcony drain or a bathroom and wash the leaves, tops and undersides, with a firm spray of water; this alone knocks off most aphids and mites. Pick caterpillars off by hand in the evening, when they come out to feed. Wipe mealybug clusters off with a cotton bud dipped in rubbing alcohol. Cut off any shoot that is badly infested and bag it rather than leaving it on the mix.

Soap and neem sprays

A soap spray works on contact against soft-bodied insects. Mix one teaspoon, about 5 ml, of a plain, mild liquid soap in a litre of water. Avoid anything with a degreaser, bleach or strong perfume, which can burn leaves. A neem spray lasts a little longer and deters pests from feeding: 5 ml of cold-pressed neem oil and two or three drops of liquid soap in a litre of lukewarm water, shaken well so the oil mixes in. Make it fresh each time and use it the same day; it loses strength once mixed.

Test on a few leaves first and wait a day. Ferns, succulents and some thin-leaved plants are sensitive to both sprays. Spray in the evening, never in sun or midday heat, and soak the undersides and leaf joints, where pests hide, not just the tops. Repeat every five to seven days for at least three weeks. Eggs survive a single spray, and it is the second and third rounds that catch the young as they hatch.

One spray kills what is there today. Three sprays a week apart clear the problem. Most infestations that come back were sprayed once and forgotten.

On herbs you cook with, rely on washing and hand picking first, and if you do spray, rinse the leaves well before using them. Label the spray bottle, wear gloves if your skin is sensitive, keep the spray away from your eyes, and store it out of reach of children and pets. Leave ladybirds and spiders alone: they eat aphids and mites, and they are a sign the balcony is finding its own balance.

Keeping them away