Doolittle and Taylor always said the best stimulation is to leave them enough stores in the fall so they have plenty to spend in the spring. If I fed syrup here right now it would kill my bees with the condensation. Also, if I succeeded at getting them to raise a lot of brood they would get caught in a cold spell and cold starve. It does not work well in my location.http://www.bushfarms.com/beesfeeding.htm#stimulativefeeding
