This is a most valuable genus, providing colour over a long period from early summer. Many varieties are suitable for the herbaceous border, but there are also many that are of a size appropriate for rock garden use.

Geranium macrorrhizum 'Snow Sprite' is a white-flowered variant of what is probably the best ground-cover plant we have. It grows on our sunniest banks and under trees, quickly spread to cover ground, virtually completely excluding weeds. It is easy to get extra plants by tucking stems under the soil, and it is equally easy to get rid of surplus simply by pulling stems.