I grow red cabbages to make sauerkraut so I would appreciate having a fair amount of them to harvest at any time. Last year I planted perhaps a bit late and some didn’t fully heart up before the winter. To be honest I am a bit confused on how to find out if a brassica is early or late. I din’t manage to get the variety you recommend in your book (Marner Lagerrot).I have Red Drumhead and Ruby Ball F1.
Please could you advise on best times to sow these?