Baptisia australis var. minor (Dwarf blue false indigo): A compact form of Baptisia australis. Purple-blue flowers like a lupin with bright green trifoliate leaves. Prefers a sunny spot. Hardy. Up to 50cm

Eryngium 'Pen Blue' (Sea Holly 'Pen Blue): Electric-blue thistle-like flowers with a spiky collar and silvery-green foliage. Long flowering and attractive to bees. Hardy. Up to 60cm.