Joanne White of Durban North writes The young leaves of my ‘VLV Kaapland’ rose are crinkling and smaller than usual. What is causing the damage?
Ludwig replies It is most likely aphids and thrips that have come out of winter hibernation. Careful inspection should reveal tiny aphids on the buds or underneath the leaves. However, the type of thrips that has become prevalent in roses in recent years is virtually invisible in the larvae stage.
The adult thrips lay their eggs further down the stems beneath the bark. When the larvae hatch, they move upwards to the new leaves and puncture and suck them out from the underside, causing this curling and deformation.