The message
from Janet Tweedy contains these words:

In article , david taylor
writes


The general advice is useful, but you will need a fine and
comprehensive net
to keep off large white butterflies.

Where can you get those little black ball things with holes in, you can
build temporary netting structures with them by making a cage out of
canes and use the balls to connect the canes together. Tried all year to
find them. Must be putting in wrong description into search engine.

janet


I've used Harrod Horticultural which seemed to be surprisingly
reasonable and have a good range of fine-mesh netting in useful widths.
It does make a huge difference to brassicas if you can net them
effectively. The annual erection of my brussel sprout cage is a ritual
second only to the building of the runner bean supports.

Janet G