I cut an article out of my RSPB Birds magazine about bees yesterday so here are their recommendations.
Foxgloves (I echo that)
Globe Thistles (Echinops)
Coneflowers (Echinacea)
March to May: Lamiums, Lungworts, crocuses.
June to August: Lavender, Coneflowers, Foxgloves, Comfreys, Thyme, Borage, Cranesbill, Hebes, Echium, Salvias, Penstemons, Heathers, Blackberries, Clovers.
Sept to Oct: Ivy, Dahlias, Asters, Sedums, Catmints, Scabious.
Nov to February: Mahonias, Strawberry tree, Salix aegpytiaca, winter Heathers.
My advice is to walk round a garden centre on a sunny day and see which plants the bees are hovering and crawling over.