Not all bee live and raise their young in hives. We tend to think in cartoon pictures when we think of where bees call home. We conjure up pictures of trees with honey holes a la Winnie the Pooh, or we think of the tidy boxes set on a meadow's edge.
Honeybee hives near linden trees and clover meadow
In fact not all bees are social and live in colonies like honeybees that have been domesticated to live in manmade hives. Native bees whether they are social or solitary species live in the ground, tree cavities or other hollow compartments found in nature. Some species live in separate cells within a colony while other live in their own cell by themselves.
The tiny hole at center is a single cell bee nest.
No matter their lifestyle they need bare soil and a bit of mess in the garden. Neat as a pin gardens with every inch covered in turf and mulch leave those bees without the necessary material for nest making. Landscape fabric and impermeable plastic are even worse.
Some bees live in colonies in tree cavities
Other bees need some debris in the form of hollow stems, tree cavities, clumps of grass and other plant material where they can find shelter and reproduce. You can supplement this with manmade "insect houses" like the one in the picture that provide the nooks and crannies that form "condo" like crevices for insect habitat. In addition they are kind of decorative like birdhouses. You can even buy Mason bee houses, or make them by drilling holes in wooden blocks. Place these around the garden, the bees will find them, and appreciate them.
Manmade insect habitat