Pest traps and barriers

Traps do two jobs: they tell you which pest you have and how many, and they catch enough to keep numbers down. Put them up before the pests arrive and check them weekly.

Sticky traps

• Yellow sticky traps: for whitefly, aphids and adult leafminers.
• Blue sticky traps: for thrips.

Hang them just above the canopy and raise them as the plants grow, and replace them when they are covered. They catch beneficial insects too, so do not leave them next to flowering herbs.

Pheromone and light traps

• Pheromone traps: a lure that mimics the female’s scent so males come and stick. Each pest has its own lure: tomato leafminer (Tuta absoluta), fruit flies and the red palm weevil. They are best used for monitoring: when the first catch appears, start protecting the crop. For the red palm weevil, do not treat it yourself — report it to the Ministry of Municipality.
• Light traps: a lamp over a tray of soapy water at dusk to catch night-flying moths and beetles. They catch beneficial insects too, so use them only during an outbreak.

Home-made bait traps

• Fruit trap: cut a ripe banana into three or four pieces, peel on, and hang it in a small jar with a little vinegar and a drop of dish soap, so the flies drown. Some recipes add a chemical insecticide to the banana — leave that step out. Poisoned bait left in the open can harm bees, birds and pets, and defeats the point of growing organically. A drowning trap is enough.
• Soured rice-water trap: soured rice-cooking water with a little jaggery in a shallow dish or a cut bottle. It draws flies and some moths.
• Holy basil (tulsi) trap: a handful of crushed leaves, 10 g jaggery and a little water in a shallow container. A traditional lure for flies and moths.

Put two or three around the edge of the bed and refresh the bait every three or four days, since it goes off and smells; empty it away from the garden.

Slugs and snails

Coat the inside of a disposable plastic cup with oil so catches cannot climb out, bury it about three-quarters deep, and fill it three-quarters full with a mix of 1 tbsp yeast, 2 tsp sugar and water. Check it daily. Slugs and snails are most active after evening watering, so water in the morning.

Ants

Ants are rarely the real problem: they farm aphids and scale insects for their honeydew and defend them. Deal with the sap-suckers and the ants leave. To keep them off a plant or pot:

• Dilute 1 tsp of 3% hydrogen peroxide, or 1 tsp of vinegar, in a litre of water and pour it along the trail and at the nest entrances.
• Sprinkle turmeric powder across their path.
• A baking soda and sugar bait that the ants carry home. Put it on a saucer or card away from the bed: baking soda adds sodium and pushes soil that is already alkaline higher.

Barriers

Insect mesh (about 50 mesh) on a frame from the day you plant is the most effective control for the cabbage family and cucurbits: it keeps out whitefly, diamondback moth and flea beetle before they start. Lift it or open the top when the crop flowers so pollinators can get in.