This plant seeds itself about on any bare piece of ground we have and is most prolific in our allotment where the soil is cleared in autumn and it can germinate before the winter arrives. We chose to let it flower in a bigger area this year, leaving it growing on a patch we dont need till later in the year, and have been very impressed by the constant stream of bees it has attracted. I have been paying careful attention on all the main local weeds and this one seems to attract more than the dandilions or any other herbaceous weeds currently flowering in our area.
We have seen each species of queen bumblebee visit as they begin thier lifecycles; first the huge buff-tails, then the carders and more recently red-tailed and early bumblebees. The honey bees dont seem so interested but maybe the small flowers are too long for them ...or its because the oil-seed rape is beginning to flower. The dead nettle has bright orange pollen which give the foraging bees an orange stripe on thier heads. This weed is particularly useful to them as that pollen may be in short supply if there are few flowering trees in your area. It's certainly one of the few herbaceaous plants flowering vigorously and attracting bees at this time.
We will need to weed it out soon before it drops excessive amounts of seed but it is really easy to remove as it spreads from a central stem so the hoe cuts through it very quickly.