Confusing brussel sprout plants with cabbages

[buildersmate]

First time I've tried growing brussels (Evesham Delight). The fast-developing plants currently resemble 'open' type cabbages, with the largest leaves as big as your hand.
1) Does this sound right (or have I mixed up my seed for the cabbage seed)
2) If so, at what point in the development cycle does the long single stalk start growing up?
The packets don't tell you.

[rowanwitch]

sounds about right should start shooting skyward soon, check where the leaves join the stem to see if any baby sprouts are forming in the'armpit' by now the first ones should be about pea sized

[buildersmate]

Thanks for the swift answer - presumably delivered via broomstick.