Touted as the best double-flowered cranesbill geranium ever seen, and having its debut at RHS Chelsea Flower Show this year, 'Cloud Nine' really is a spectacular specimen. Smothered in wonderful lilac blue, double flowers twice in the season - once at the beginning of summer and again at the end - this lovely geranium is strong-growing, pest and disease resistant, and can reach up to 90cm (35in) tall once established. Bees and other pollinating insects love it too!