it depends how big you expect them to get.. I think its for every foot to a gallon
BukDatAss Reviewed by BukDatAss on . What size pots when plants are finished? I just put my plants into 5 gallon buckets. Is a container this size really needed? Could you get away with anything smaller? 3 gallon buckets won't save much space because they have the same diameter base, what do you use to save space that is big enough to finish in? Rating: 5