We got our first batch about a month ago. The hives are being handled by a professional beekeeper, and he's still adding the sugar water. It probably depends on how much natural sugars are available. You certainly are further ahead with blooming plants than we are in Northern Illinois. If there's a beekeeping group in your area, they'll probably be a good source of information and support. Good luck.
It all depends on the nectar flow and how strong your hive is. The best way is check your hive once a week and look for white caped combs of store honey or sugar water stop feeding. Me I only feed up till there a nectar flow then I stop feeding. There some beekeepers out there that don't even feed. I also recommend brood builder patties it help build your brood faster.
as a responsible bee keeper, it depends on how fast your bees gather honey nearby your place. if they cant find any sufficient supply of natural sugar, you still have to provide them with sugar water. - http://www.beekeepingsuccess.com/