OK, well we have lots of problems with honey bees, which are dying by the million. So far there is not a lot we can do about that, other than eschew pesticides in our gardens. Look what we spotted in the Dalea bi-color today - a very happy lynx spider dining on an unfortunate honey bee. There are also many species of wild bees and they are very busy pollinators, valuable in the garden and small farms bordering wild lands. We have many in our garden and they too love the Dalea, a heavy bloomer in fall, and a light bloom in spring. It turns out that all that mulching that we do to save water is very detrimental to wild bees who live in small nests in the ground. Apparently the bees cannot find their way to the soil. Native bees need bare ground in which to nest. The natural leaf litter lying under trees and shrubs is not a problem, just the thick layer of wood chips that many of us lay out to stop evaporation.
So we're down to the nub of the matter. If we want to promote native bees we should leave the ground alone, no blowing, mulch around the plants, and leave some bare areas. There is always something that comes up when we think we are doing it right. Of course, native bees like native plants.