So what we do
Tubers out of packet or winter storage
Place in pots with slightly more earth to just cover tuber but leave shootes exposed and water a little.
When they get 3 branch joins high, nip out the first section to encourage more stems and plants after danger of last frost has passed. Keep out of strong cool winds if possible whilst in pots to stop wind burn on young leaves. Getting ready to lift ours but we've not had a frost yet and last year they were lifted November 9th as I got fed up of waiting lol.