Categories: General Date: 17 Mar 2011 Title: Keep OUT!We've been experimenting with ways to keep the dreaded cabbage white butterflies away from tender baby brassicas.
Unless you're prepared to 'find and squish' the little green grubs every few days, or use Dipel regularly, your brassicas will probably be hit by the cabbage white butterfly larvae. These little green grubs grow quickly after hatching from their tiny yellow eggs, usually layed on the underside of the leaves. When seedlings are small, the grubs can eat almost the entire plant mass in a day or two. Buggers!
An alternative to chemical or physical warfare is the good old exclusion method! We've been making frames from various materials, which can support netting, mesh or insulnet that helps keep the butterflies from laying eggs. The frames need to be light enough to easily lift on and off the bed. Alternatively, if they are fixed in place, the netting needs to be easy to lift up to enable weeding and picking.
We think that the Kerilea system of hoops (on left in picture) offer a versatile option. The hoops can be poked into the ground, or screwed onto the edges of beds. Then you can choose netting, plastic or whatever covering suits the time of year and the crop in ground. There is a system of wire clips that hold the netting in place, and its easy to clip the sides up if you want ventilation or good access while working.
We'll be offering a system like this as part of our raised bed packages in future. If you'd like to help us trial these systems on your existing garden beds, let us know!