At the local bee club meeting, last night, we had a guest speaker come in to talk about Planting for Pollinators. She was from a local nursery. While she admitted, even though they have two bee colonies on the property, they were the responsibility of someone else. Her expertise was in plants. She had compiled a list of plants for our zone 5 location. In general, she explained that bees are attracted to the colors yellow, orange, blue/purple and ultra violet. Shapes they prefer are shallow, tubular, and flat. They also like flowers that are symmetrical. Flowers will guide bees to themselves through ultra violet light (I hope I worded that correctly) The bees are also attracted by the sweet or minty smell of nectar.
For our area, the big 4, can't go wrong plants to plant are Borage, Goldenrod, Lemon Balm and Tanzy (invasive).
She was a great speaker and took the time to compile her own list, broken down much like you would see on someone else's web site. She focused on season of bloom, nectar or pollen source, native, invasive, height, annual or perennial.
This doesn't help you much Rob, but it gives you some ideas on what might work in your area.