Ecologically responsible beekeepers can follow this very simple recipe:
To reduce competition from honeybees on other bee species plant more flowers than you have honeybees.
As bee and pollinator diversity declines it is tempting to keep honeybees in the mistaken belief that this will help. It likely will not and in fact may make the situation worse.
Honeybees have a valuable role to play in our food system. Bees and flowering plants co-evolved; it makes sense that since many of our food crops came from Europe and Asia that we would import the honeybee to pollinate those crops. Because of the natural history and biology of the honeybee they can be safely moved from one location to another for pollination. Farms and orchards can go from no bees at all to having millions overnight.
Diversity of plants is mirrored by pollinator diversity. Hundreds of thousands, even millions, of honeybees in an area does not equal biodiversity or result in ecological health. Every species of bee has a preference of flowers to visit, honeybees too. Honeybees are able to flourish in fractured and discontiguous environments, many bee species do not and when already in decline are forced into further stress by the presence of honeybees that can power through a depleted landscape to gather pollen and nectar to survive. Unfortunately in those places other bee species go down in population and in species diversity.
Having loads of honeybee hives in one spot does not mean they distribute their pollination services equally across all the flowers in that area. Honeybees are very attracted to some flowers more than others and are unable to pollinate some flowers altogether. Overall, honeybee pollination efficiency is about 14%, much higher on some flowers and nonexistent on others. Honeybees are great, wonderful, even magical organisms, but they can’t do it all. They cannot carry us forward into a sustainable future without the presence of all the other bee species.
People keep honeybees, I keep honeybees, honeybees (hopefully) are here to stay, honeybees are essential to our agricultural system (not respected or treated right, but just the same, essential) and they are amazingly complex and fascinating creatures. I don’t regret keeping honeybees or encouraging others to keep honeybees. But we need to do it right by adding nuance and sophistication to our understanding of what is really the matter.
What kind of flowers to plant? All kinds of flowers! Flowering trees, shrubs, ground covers, annuals, perennials; every season have something in flower; diversity of colour and shape; always have some native wildflowers in your garden to more directly support our native solitary bees.
We need bees, all of them, bees need flowers, plant more flowers than you have honeybees.
The Bee School 
Well said, Brian! When we moved into a compulsively manicured neighbourhood we had a lovely large yard devoid of pollinators of any kind; no birds, and no earthworms. Not one worm could I find in lawn or flowerbeds. We planted deliberately to draw in birds and pollinators, banned the pesticides and herbicides that kept the yard so perfect and perfectly sterile, and began building the soils with composts and manures. It took time…three years till the first earthworms returned, but now we have a vibrant backyard ecology, filled with birds, pollinators, plants and flowers. The native bees love our lovage, fennels, dills and Joe Pye Weed. The honey bees agree but also love the masses of catmint and phacelia. The bumblebees mass on our borage and lavenders. We are now moving to plant the empty and wild spaces and paths in our neighbourhood, adding plants and forage seed mixes. And we let the dandelions bloom!
There are two things of interest about earth worms; one is they are not native to most of Canada! We can blame the ice age for that. Basically glaciers scraped our topsoil away, along with earthworms and other soil borne creatures. The average topsoil depth in Nebraska is over 10 ft and in Alberta less than a foot. Since the end of the last ice age soil has been slowly rebuilding while the organisms we associate with healthy soil are still recolonizing. The other thing of interest, to me anyway, is bees are descended from an ancient form of worm. Bee segmentation has a parallel in today’s earthworms. There are numerous connections between bee and worm physiology, nervous systems and other related anatomies.
I applaud your efforts! Thank you for the positive comment.
The point I’m trying to make is honeybees don’t equal ecological health. They have a role to play in our economy and in pollination ecology but we shouldn’t put all of our honey in one jar. We need all the bees.
There is a wonderful National Geographic article on Jamestown which mentions the effect of earthworms on the New World forests, which prior to worms were open with deep drifts of leaf litter. Worms digest and eliminate that layer, and an understory sets up. Here in Delta I see more hedgerows coming down this fall, so sad. All the more reason to plant every and anywhere.