Posted: 19/09/2015 at 09:25
I regularly see bumble bees visiting them along with other bees in one of my clients gardens. Hoverflies and and other small insects visit them as well. So I'd say they are a useful source of nectar for some insects although I suspect they aren't as pollen rich as other plants. The recent weather hasn't been good though it's been too cool but on warmer days I do notice the the visits.