Growing the Desert Garden

Welcome to the Desert Garden, with garden coach Tyler Storey, where we talk about everything having to do with gardening and landscaping in the Desert Southwest. From composting to Cercidium and agaves to arugula — we'll cover everything you want to know to grow your own beautiful Desert Garden.

Wednesday, January 14, 2009

Back at the Ranch: Cauliflower Caterpillars

Caterpillar on Cauliflower Leaf ┬ęTyler Storey

One of the benefits of Winter vegetable gardening is the reduced level of pests. Even the intermittent cold periods are too much for most insects and other critters, and with luck we can come through the season with limited insect damage. But there are always a few hardy fellows who buck the trend, and it's worth keeping an eye out for these guys.

I noticed a few holes in the leaves of one of the cauliflower plants the other day; clearly a caterpillar was at work. It took about 2 seconds to track him down. You will almost always find caterpillars on the back or underside of a leaf, and sure enough, as I turned over the leaf, there he was, looking rather fat and contented.

Sometimes you have to do a little more tracking to find the culprit, so keep these tips in mind:

  • if there are little holes and big holes, look behind the big holes; the little holes were earlier meals from the smaller caterpillar;
  • if there are holes with tan or dry edges, and holes with fresh green edges, look behind the fresh ones. In the photo, look at the edges of the hole to the left of the caterpillar and notice the thin, dark edge of the hole (click to enlarge); that's the tell-tale sign of fresh eating;
  • and, if you don't find the caterpillar on the leaf, look carefully along the leaf stem or rib; a caterpillar will blend right in with the stem.

If this were Spring and you had a heavy infestation, you might spray with BT, an organic caterpillar-killer. But with one or two caterpillars in Winter, don't bother; just pick them off and toss them onto the nearest walkway. The birds will appreciate the treat.


Anonymous said...

Hi i just found a bunch of caterpillar from my cauliflower :(
i want t obuy BT but i dont know where to buy it in UK. do they have different name here?

Tyler Storey said...

I am not familiar with the UK labels for Bt, but you should be able to find it at your local garden center, or perhaps at one of the mail-order houses. Bt is of course an abbreviation of Bacillus thuringiensis, so if you ask for that at the garden center they should be able to direct you. Good luck! And, remember: on many plants, picking the little beasts by hand works just fine.