What time of year is best to requeen hives?

Queens are readily available for purchase April-September. Thus, it is best to plan to requeen during those months. Hives most readily accept new queens when there is a natural honey and pollen flow, or you are feeding the hive. So, if you requeen in April or May, they will naturally be more inclined to accept the queen. Most beekeepers requeen in April & May. If you want to make a honey crop it is best to requeen as long as possible before the honey flow begins to let the hive recover and rebound before the flow starts. 

So, early to mid April is typically the most ideal time to requeen. However, requeening from June-September is effective, and queens may be cheaper, and are not sold out as they often are in April. Plus, you don’t have to disrupt your hive and the growing process right before the honey flow. If you do requeen in the summer months, be sure to trickle feed to help the bees accept the new queen.