Nepeta is the winner by far, despite the competition from the cats! The runners up are Buddleia ‘White Mrs Keep’, Buddleia ‘Adonis Blue’ and Veronicastrum virginicum ‘Lavendelturm’. My apple mint (Mentha suaveolens) has just started to flower. It can grow over three feet tall, and I always allow some clumps of it to flower because bees and hoverflies seem to love it so much.
Of course, as preparation for honey bees, buying and planting a huge array of different plants is a bit counterproductive really. Honey bees are a bit like some of the people who appear on Freaky Eaters, they go for one foodstuff and then refuse anything else. Once an individual bee has been persuaded by a colony mate to go for one particular species, that bee will only go for that plant. If supplies run out it will apparently, – unless it is very young, and flying workers only live for about three weeks any way – starve rather than go to a different plant.
Bumblebees however like a bit more variety in their diet, and they seem to have a go at whatever’s available. This sounds like a much more sensible way of doing things; I can’t think of any evolutionary reason why sticking to one plant species for life would be a benefit. Within the colony they might feed on a variety, so perhaps individual specialisation has a benefit for the whole, but I can’t think of one!