Globe thistle. Wooly stems with spherical dark blue flowers in midsummer and prickly divided green leaves. Looks wonderful in bold drifts and  towards the back of mixed perennial borders. Any ..

Wooly stems with silvery white flowers and prickly divided green leaves. Best in sandy well drained soil in full sun or part shade. Height 100cm, spread 60cm. ..

Round, blue, globe flowers top 3-5ft stems in summer. Glaucous green foliage. Best in sandy well drained soil in full sun or part shade. Height 100cm, spread 60cm. ..

Spiky electric blue flower heads on silvery stems above divided silvery green leaves. Any soil. Best in sun. Height and spread to around 1m x 45cm.    ..

Prickly deeply cut greyish green leaves with white globe flowers on maroon stems to 80cm tall from mid to late summer. Best in fertile, free draining soil in sun or part shade.   ..