I prefer to do them separately, for a couple of reasons, even though it entails more work. First, it is interesting to customers to see the different honeys, and promotes interest in your product, and many will want to buy some of each. Secondly, occasionally bees gather nectar from a plant that produces undesirable flavors (to humans, at least) and you would not want to mix that honey with the good stuff. Here in Central Texas, we have a plant called bitterweed that produces a very unpleasant-tasting fall honey. Other fall plants produce an excellent, dark-as-molasses honey that I prefer to any other.
"I am the Good Shepherd. The Good Shepherd lays down His life for the sheep. " John 10:11