Reading up on motherwort, I'm jealous that it only grows in more northerly climes. No clue what its honey would be like, if I were you I'd definitely give it a go. Plant tons of it!

You know every year I'm gladder that we live in northern climes...except in about November-March. :)

Found this on a Richter's page about herbs and beekeeping. I'm not sure 'strong mint flavour' is a good thing...But then our bees would not be restricted to motherwort...

Motherwort (Leonurus cardiaca)
Widely acclaimed beeplant, blooming most of the summer. Very easy to naturalize in waste areas. Honey is amber with a strong mint flavour. Remains liquid for months. Perennial.

Here is a link that might be useful: Richters

I have it growing in a large flower bed. It spreads like weeds, but is such a bee magnet, you can't see the flowers for the bees. I have no idea where it came from, but I have left it because of the bees. It seems to thrive in almost total shade, full sun, dry as a bone soil. Out of hundreds of flowers and herbs I grow, I've never seen anything attract bees like this stuff. It'll take over your yard if you let it.

Jane

Yes - every year it selfseeds like crazy. Luckily the seedlings are easy to rake or pull out. We have it at the edge of the vegetable garden.
Good to know it will also grow in shade.