Arlene, I thought it might be a good idea to mention continuous planting of broccoli, which sure does not hold in the garden for me.
I made the mistake the first year I grew it of planting 9 transplants on the same day. Did not realize that this would mean 9 beautiful heads of broccoli all ready to use (and must be picked! or they go to flower) in the same week, a couple of months later. My neighbors were very happy.
Now I plant 4 plants, then wait a few weeks and plant 4 more, through the fall and winter here. I still have a head or two to give away. Being as I live in Florida, it can get warm any time so once there is a nice head it's critical to pick it or a few warm days will send it along to flowering immediately. I'm sure this is true in other places as springtime progresses, too.