I am planning to purchase the grafted Black Pearl aubergines from organic plants uk as you recommended. Would you have them delivered April, early May, late May or June if growing in polytunnel? Also do you pot them on and grow undercover for setting out later?
It depends whether you can grow them on in warmth. I receive mine soon and pot them on in the greenhouse over the hotbed, they are flowering by mid to late May.
If your propagation facility is less warm, perhaps request early May. They are small at delivery but grow fast.