there are a couple of good books by a lad called dave goulson, well recommended if this is an interest.I was reading a thing - can't remember where - and the bee experts don't want us creating more hives, they want us growing more habitat
Like having your garden full of pollinating flowers and plants is better than a hive
our ceanothus (aka californian lilac) has been humming with bees recently. we've considered getting those yokes dudley has - echiums - but the garden is kinda full already.