dusty daisy bush 'Comber's Blue'

'Comber's Blue' is an upright shrub up to 2m high with oblong to narrowly obovate, aromatic leaves 3-4cm long with shallowly toothed wavy edges, grey-green above, densely covered with white or grey-white wool below, and many clusters up to 7cm across of flowerheads, each 3cm across and with mid-blue ray-florets and yellow centres, so that they look like shrubby Michaelmas daisies, but flowering in spring and early summer