Plant Doctor Archive

 MY garden outdoors is just covered with whitefly. I have not a lot of money to spend, so was wondering if you have any really cheap ideas on how I can control it.

 I MUST admit that I spray nasty insecticides when I get whitefly, but I chatted with the manager of our hortecology unit, Richard Main, and asked him what he thought. He suggested that you could try spraying with soapy water — this can discourage whitefly and other similar insects.

Otherwise you could try to encourage beneficial insects, such as hoverflies, which will attack the whitefly and keep their numbers in check. Hoverflies are attracted by plants of the carrot family (Umbelliferae/Apiaceae), such as carrot, dill, coriander, Queen Anne’s lace, etc.

Richard did have one last suggestion, which was to collect some whitefly and blend them with water, and then spray the result on the plants to discourage the rest of them. All I can say, is, don’t use my blender...

• The views expressed here are not necessarily those of the RNZIH
• Content or advice may be out-of-date.