Spring Cabbage

alleycat`

Morning green thumbs,

I have an issue with my sping cabbage.
I've started two lots off now.
They all do really well up to about 4 weeks then the 4 or 5 leaves they have start to curl under at the edges and then eventually die off.

I've tried varying them in different composts, straight in the ground and different water / location regimes.

All with the same dead loss.

I have never had issues with cabbage before so i'm utterly stumped unless i've bought some bum seeds (these are new for this year).

Germination rate is nearly 100% as well.
All very odd.

Lotus-eater

It won't be the seeds. Could be any of the usual brassica problems, although to affect all of the cabbages is a bit odd. What do the roots look like when you pull the dead plant out?

alleycat`

Roots are long - one main tap root and a few branched roots.
They look in pretty good condition which has added to my confusion.

Lotus-eater

Well I don't know then, sorry. Maybe a picture would help.