Remember to keep an eye on the stores in your hives by giving them a heft periodically. The queen is likely to start laying in earnest soon and the remaining winter stores can soon get used up. Late winter and early spring are the danger periods for lack of stores, so don’t risk your colonies. If you need to feed them now, use candy or fondant. You can use light syrup (1:1 by weight) in a contact feeder once the weather warms up and the signs of spring start to appear, especially if you want to build up a colony for queen rearing, or to split. Don’t use a rapid feeder, or pan feeder as NBU now suggest we should call it, though as it may be too cold for the bees to come up. For more information see BeeBase’s Best Practice Guide to Feeding Sugar.
Remember too that bees need energy food (sugars) and protein (pollen). Raising young bees takes a lot of both. So in addition to making sure that sugar is available in liquid form stored from last year (honey or fed in late summer as sugar syrup) or in fondant form make sure that pollen or a pollen substitute is available. See this Feeding Pollen and Pollen Substitutes guide on BeeBase for more details.