I started mine off early, single seeds (Prinz) in modules on the windowsill, then out to the unheated greenhouse to grow on a bit, planted out onto the plot when around 8 inches high into a sunny bed on heavy clay, planted through weed control to keep the soil warm but moisture in. Fed every two weeks, initially with home made nettle tea, then switched to comfrey tea. Watered when the soil under the weed control seemed dry (Only twice last year) and pulled away the leaves gently when they dropped to lying horizontal. The results have been fantastic, I have started to harvest and they taste excellent, good size too average 5-6 inches across at the moment, but I'm leaving them in to see how big they grow, if they keep well in the ground, and if they start to taste 'woody' at any point. Hope this helps.