Sort:  

4 of a certain size ... which means you could be growing a lot more smaller ones and then chop the big ones down when ready.

It will be very difficult to regulate.

Oh I'm sure that they can do it.
Require a license to grow.
with periodic visits from inspectors.
have LOT of regulations..(plant size, color, spacing, number of leaves)
with HUGE FINES for breaking them.
it should be a lot of FUN.
I hope you all enjoy it.

No licence required as far as I can see