There are many factors. Minerals are used and sought after by deer at all times of the year, but spring/summer is most important and popular. Does need to replenish minerals lost by giving birth and to keep their fawns healthy while still carrying. Fawns need minerals to help them grow. Buck use minerals to help develop their antlers.

But before you start thinking that salt/minerals are "The Answer" to hunting and growing big bucks, think again. Mineral licks will help your deer, and they create a great place to get pictures and observe deer. But minerals arnt going to transform bucks into slammers overnight. Genetics and diet are still #1 and #2 for this, and mineral effect is truthfully very minimal when it coems to growing huge antlers.