I sowed some Sea Kale seeds about 5 weeks ago (Lilywhite from Garden
Organic). Three have come up and are now about 2cm high, and that's how
they've been for a fortnight now: they seem to have just stopped. Sown in
John Innes seed compost in an unheated mini green house, minimum
temperatures have not fallen below 10 here in Jersey.

Am I doing something wrong? Why have they just stopped? or is this
normal? I've never tried to grow it before, as you can probably guess!