What's attractive

[nellie-m]

No bulbs, but very popular with bees and butterflies are the origanums, too, and if it hasn't been mentioned, hyssop (which also comes in white and pink, btw, though you may have to search for those rarer colours).
If you like something higher, have a look at the cup plant, a good nectar source for all sorts of insects.
Silphium perfoliatum - Wikipedia, the free encyclopedia

[Alicante]

I also grow flowers for beneficial insects including the allotment bees. Nigella, foxgloves, cornflowers, sweet peas, opium poppies, pot marigolds (which are still flowering now) and californian poppies. A nice mix of colours, especially the californian poppies which are always a surprise because they are self seeders and can be white, pink, pale yellow or orange. You only need to sow these seed once and they come up every year. Whats not to like!
I also grow gladiola and the bees really love these, they have the added bonus of lasting a long time as the flowers on each individual spike dont open all together.

[snakeshack]

Grow phacelia as a green manure on unused ground when it flowers the bees love it

[jackarmy]

You mean appart from female Bumble Bees im guessing ?

[WendyC]

Hopefully Rob might pop back to see your suggestions but hasn't posted for over a year.

[Madasafish]

Grow phacelia as a green manure on unused ground when it flowers the bees love it

+1

Urban Pollinators: Phacelia tanacetifolia – a great plant for bees

My bees love it... and it has a lovely smell.