A bewitching annual that brings the diaphanous white clouds of cow-parsley into the garden without the place being overrun and everything else being swamped. The flowers are a clear, bright white and resemble lace-cap hydrangeas. What look like enlarged petals around the edge of the flower act as landing pads for small insects. The popularity of this plant over the past eight or nine years has encouraged gardeners top return to sowing annuals. You usually find a few self-sown plants in the second year but the best policy is to sow your own each year. You get larger, early-flowering plants from sowing the seed in October or November. Grows to about 45cm tall and flowers from May to July.