If you were to do things in this fashion you can also split the contest, for one set of photos and one winner for autos. There's my 2 centsThis will be a long contest. Think about that. And you can collect sponsors donating prizes over a longer period of time. Better Prizes, better growers, better techniques.
3 months for autos is what I've always read but some do go a extra 4th month I heard all depends on gene pool.i've never grown autos so i don't know the time frame that it needs. I do see the point of having a end date as it will make the challenge more challenging for photoperiods but not for autos.
another point is that not a lot of growers are able to start in March and with without an end date these growers can still play along when they are ready. However, this will make it difficult if we get lucky with getting prices lined up.
i think so far @ComfortablyNumb suggestions has been the best with no additional rules except for one gallon.I can see that the juice isn't worth the squeeze for a 12/12 from seed grow yield wise... But I also don't think its much of a challenge if you get 8 months to grow and finish a photo plant so there's both sides of the coin
in the past challenges there has been all sort of systems. Also, it's not about the speed of the grow but rather how your system and tactics are, how the flowers and plant look.Any hydro grower will blow a soil grower out the water with a one gallon pot limit. So this will just end up being a hydro challenge