I think bees and other pollinators are hard to find in lots of places around our country. There has been a dramatic decrease in the numbers of all types of pollinators in recent years for a number of different reasons. We all need to do what we can to restore habitat and avoid use of chemicals whenever possible. I am teaching my colleagues at work all about gardening with native plants, and showing them how to raise milkweeds to attract Monarch Butterflies. If you are benefitting one type of insect, you are most likely helping a bunch more that you aren't aware of.

you have to keep in mind that honey bees may prefer one food source over another. just because you don't see them doesn't mean that they are not there. they may be on tulip poplar trees or other greater nectar producing plants, once the nectar source has dried up they will move back to the clover. keep an eye on the native pollinators (bumblebees) they are a good indicator on what food sources are available.

EXAMPLE: if the bumblebees are all over the clover then so should the honey bees, if there are honey bees in your area. and vice versa, if there are no bumblebees any where on the clover then they more the likely have found a greater quality food source somewhere else.