A striking rhizomatous perennial which typically grows in dense, bushy clumps, producing masses of single yellow, daisy-like flowers throughout the summer. Known commonly as whorled coreopsis, this plant holds the coveted RHS Award of Garden Merit and makes an excellent border filler with its well-branched habit and airy clumps of feathery leaves. Coreopsis verticillata 'Zagreb' is useful not only in herbaceous borders, but grows well in patio containers, where it attracts swarms of bees and butterflies to its nectar-rich blooms. Height and spread: 30cm (12).