When growing any vegetable in the Brassica family during the warmer months, there is a risk that they may come under attack from caterpillars of the Cabbage White Butterfly. The easiest way to keep these green little caterpillars from devouring your prized vegetables, or turning up in the florets of your broccoli at the dinner table, is to make an insect exclusion tunnel.
The Brassica Family includes: Broccoli, Cabbage, Cauliflower, Kale, Chinese Cabbages, Mustard, Brussel Sprouts, Kohlrabi, Turnips, Mizuna and Radishes.
To make a tunnel you will need::
-Veggie netting (2mm mesh size-available from various online suppliers)
-black poly pipe (with a diameter that fits over your stakes)
-timber stakes or star pickets
Step 1- Hammer your stakes into the soil at regular intervals, opposite each other, around the edge of your vegetable bed.
Step 2- Measure and cut your poly pipe to lengths that will form an arch over the shortest sides of your vegetable bed. Push them over a stake and bend across the bed to the opposite stake.
Step 3- Lay your Veggie net over the arches and secure ends by tying with twine. In windy areas you may need to use wire pegs ( you can make them yourself from old wire coat hangers) or bricks to peg the sides down. White Cabbage Butterflies are very good at finding any gaps!