Up here in Prince George zone 2, you start corn inside and transplant outside approx 15 June. Corn is started in 1 litre milk cartons. When transplanting you just have to be very careful not to disturb the root ball. The above is all hearsay. This is my first year up here and first year to start this. Very expensive way for us to have bought milk all winter so it jolly well better work. Ginny in Prince George BC zone 2