Most gardeners are aware by now that honeybees are in trouble. This knowledge is driving a surge in amateur beekeeping. Other pollinators, including native bees, are in trouble too, from the same disastrous cocktail of causes — habitat loss, pesticides, disease and parasites. Keeping a hive of honeybees is quite a commitment, and for gardeners and small orchardists, encouraging native bees is a pretty good option. You can do it by growing native plants; leaving some areas, shall we say, unmaintained; and by providing nesting opportunities.