they do need extra cal/mag in flower and you can do a worm casting tea to green them up a little so they don't blow their leaves before they finish flowering.
they are not well insulated so summers are a pain running lights and ac. if you are in a park the meter is read by someone who would know if the electricity usage is too high, they are easy to break into and ventilation can be a problem.
http://www.growweedeasy.com/marijuana-symptoms the soil they are in will have a big influence on what they need because some are heavy feeders and will need more food while others do fine.
if it isn't freezing they will be fine and you should have plenty of time, get them as much sun as possible the more sun the sweeter the bud and don't feed them the last couple weeks before you harvest. nice