The little buggers are holding back our brassicas.
If I tap or rattle our Brussels sprouts, swede, winter cabbage in fact any
brassica, a cloud of whitefly emerge from them.

The only thing good to come of this is that hoverfly are thriving.

They have all been sprayed with a solution of liquid soap and water all
over including where they hide underneath the leaves.

The swede is espescially looking poorly.

Can anyone help? even advice to avoid them next year will be welcome.

Thanks
Sandra and Micky