I have re-visited my brassicas, only 2 plants but both are strong and tall in only a 1 x 1m bed. I took the net and cage off, took the fallen and yellowing leaves out and suddenly there is air
Not wanting to waste my organic plants, which are growing alot of veg between them. I have cleaned them up, only found one caterpillar and lots of damage from slugs and whatever has caused the black poo all over
I made a litre at a time of neem/soft soap spray, 5ml neem and 10ml horticultural soap in every litre and I used 5 litres. Blasted as many leaves and as much of the stems as I could. I use a 1 litre birchmeier pressure sprayer. The leaves underneath as much as possible and the white flies dropped in a milky liquid. Now the plants look great and I can keep a better eye on yellow butterfly eggs, to squish but I hope there are no more, depends on the weather
Out of the two plants, the purple sprouting had much less damage and is the one which provides a lot of reward for space, if I do have one plant then it will be that one but the jury is out until harvest
Btw, a have never had a problem with any tight leaved cabbage such as red drummond and minicole, there are many others