Per George Imirie:
WHEN DO YOU STOP FEEDING?
It is inherently natural for a honey bee to want to get outside and fly to gather odoriferous natural nectar and pollen rather than being cooped up in a hive eating artificial nectar (sugar syrup) and/or old stored honey. Hence, you can stop feeding when the bees won't take feed anymore. However, this is NOT true in the case of new colonies started in April or May with nothing but foundation. Please note that bees WILL NOT BUILD COMB (draw foundation) in the absence of a nectar flow! Quite often, and particularly in Central Maryland with its nectar flow limited to only April, May, and maybe 10 days of June, if this new colony is not continuously fed sugar syrup (artificial nectar) from the day it was started until September, there will be very little foundation drawn, and maybe not enough to hold 50-60 pounds of winter stores needed to get to next spring!
I feed my new bee packages a 1:1 mixture using 1 gallon jars over the inner cover hole. I have noticed that when there is a nectar flow, very little syrup is taken by the bees. But when there is a nectar shortage, they chug it down!