Phacelia tanacetifolia is a plant that ticks so many boxes. It's an annual that germinates very easily and grows very quickly. I scattered seed on a vacant bed on the allotment a couple of months ago and now it's in bloom (as seen above). The haze of pale blue flowers above the lacy foliage is gorgeous and it's rated as the bee plant par excellence for both nectar and pollen.
 Phacelia is also particularly useful as a cover crop and green manure. Certainly no weeds have grown through the patch I sowed and in due course I will chop and drop to make a mulch and/or dig it in. Some sources recommend doing this before flowering but the flowers are too good to miss. I don't mind if it self-seeds (in fact I'd like that to happen). The stems will be a bit "woodier" by then but that should actually be helpful to improve the rather light soil we have on the allotments.
 Bare earth and a sunny spot is crying out for Phacelia tanacetifolia- the bees agree!