What can I plant -- I'd prefer to use seed -- in my zone 6 back yard that would provide either pollen or nectar for bees? I'd prefer them to be native to the eastern half of U.S., (but not absolutely necessary) and under 3 ft. tall. The lawn I'd like to put these plants is mostly shady, the soil is clay, and doesn't get much supplemental water, but I could water it a few times during August, when it tends to be dry. ( I'd only be mowing a path down the middle, and a path around the edge of the lawn. The center wouldn't get mowed until fall.) Not too tall an order, right? : ) Thanks.