As soon as the weather warms up enough and is dry enough for my backyard bees to fly, I will begin my program of supplemental feeding to crank up brood rearing. I have external jar feeders about 30 feet from my hives and use honey water in them. I will also put out a dry mix of spent brewers yeast, soy flour, and sugar that I have powdered myself (no corn starch). The bees will really use this pollen substitute until the red maples bloom here around the first of February. Once the red maple blooms, the bees quit visiting the substitute mix, and within a few days, I get my first phone calls or e-mails from people looking for local honey to help with allergies.
For me, that sort of marks the beginning of the spring season and is a reminder to try finish up whatever I need to get done for the spring buildup.