Anna wrote:
I asked what the purpose was and she said it made them produce heads sooner.
I think I will leave them to grow at their own rate.
............................

In a situation like this, it's a good time to do an experiment. Pull the
lower leaves off of every other one and watch to see what happens. Then
you can report back to us.
My guess would be that they don't really form a head sooner or, if they
do, the heads would probably be smaller than the others. That's what
common sense would tell me but, once in a while common sense lets you
down. Find out.

Steve