You can use the following.....................Aquilegia, Foxglove,Geranium,Rhododendron. Hope this helps

Red Bergamot ( one is called Monarda Cambridge Scarlet) is loved by bees, it is also known as bee balm. I think crocus.co.uk has it.

Lavender is loved by bees and can be grown in a pot. Bees like sage, mint, thyme and rosemary when they flower, and all these herbs can be grown in pots.

The blue agastache is loved by bees too.

Bees seem very interested in my Heuchera flowers in pots. As they flower from early to late, according to name, there is always something for bees, if there are more than one named variety in the pots. It is fun to watch a big bumble bee upside down on a tiny Heuchera flower. Jade Gloss seems very attractive to bees and has been in flower for 2 or3 weeks so far.