Jeanette is having trouble with wireworms in her potato patch and where she has grown yams.
Wireworms are larvae of Click Beetles. The larvae are shiny, brownish cylindrical creatures with 6 legs close to the head. They can grow to about 3.5 cm long, and are fond of eating roots, fleshy stems and tubers.
Wireworms can increase to pest proportions where sufficient crop rotation has not been practiced. The adults shelter in weeds or vegetable litter in and around garden beds.
To get rid of the adults, clear the garden area of weeds, old plants and mulch. You can then get the adults to shelter under a plank or bag laid on a garden bed. Early each morning, collect and destroy the beetles until it is obvious you have numbers under control.
Dig a 3 – 5 cm layer of compost into the top 15 cm of affected beds, or add plenty of organic fertiliser and grow a green manure crop to slash and dig into the topsoil when it is knee high.
Don’t grow yams, potatoes or carrots in that area again for at least four years. Rotate crops, starting with a legume, on a regular basis to prevent a build up of these pests in soil. (See Crop rotation )
Keep weeds under control and apply enough organic fertiliser to keep plants growing vigorously, and they should cease to be such a nuisance for you, Jeanette.