Those leeks and so on that Kate and I planted out together

Kate left a comment on yesterday's post asking about "those leeks and so on....."  I thought rather than just answer the comment, I'd write this separate post and put in a photo.

Kate and I planted out leeks, spring onions, fennel and broccoli whilst she was here at the end of September. In the photo, you can see the leeks and onions and some broccoli.  If you look carefully, you can just see one of the fennel plants, in front of the red cabbage.  The leeks, onions and fennel are all doing really well, but I always have trouble with my cabbage....   I just never seem to be able to get it to do what it should be doing...in this case it's being eaten by something again...  I'm spraying diligently with my recently purchased insecticide and since Kate's visit, I'm now making a new mix every time I use it... She suggested that, as they were living organisms, it would be better to mix if fresh rather than keep it for a couple of days....

I think the only answer is to be even more diligent about protecting the cabbage.  At the moment, I have them surrounded with coffee grounds, which seems to be deterring the snails and slugs, but I wonder whether a little sand pile would do a better job???