This is my first year to plant broccoli, I have nice plants of leaves, probably 12 to 14 inches across and 9 inches high but no broccoli heads are in the middle of the plants. Why is this? Also what is safe to use on the leaves they have some holes in them, I looked it up and it is an insect, although looking them over I didn't see any. Really hate to use a chemical! Thanks, Lisa