Plant a wide variety of colors, shapes and sizes of flowers for bees. Their favorite colors are blue, purple and yellow. Group several of the same plants together so there are plenty of blossoms.
Ideally there should be something blooming from early spring through fall. Provide a shallow source of water. This plant list will get you started.
Spring
Alyssum
Anemone
Basil
Calendula
Crocus
Dianthus including Sweet William
Lupine
Pansy
Poppy (Iceland, California)
Phlox
Salvia
Snowdrops
Thyme
Wallflower
Shrubs
Agastache
Bee Balm
Butterfly Weed
Black-eyed Susan
Borage
Catmint & Catnip
Cilantro
Cleome
Clover
Coneflower
Cosmos
Coreopsis
Dill
Fennel
Gaillardia
Geranium
Heliotrope
Hollyhocks
Hyssop
Lavender
Mint
Oriental Poppy
Penstemon
Sage
Salvia
Shasta Daisy
Snapdragon
Sunflower
Thyme
Zinnia
Late Summer/Fall
Aster
Goldenrod
Japanese Anemone
Liatris
Sedum