Gill Heavens selects her favourites from members of the rose family commonly known as cinquefoils
If I were to decide to have a National Collection of plants, at the top of my list of potential candidates would be potentillas, commonly known as cinquefoils. The 500 species in this genus come in many forms; shrubs, annuals, biennials and perennials, which are mostly confined to the northern hemisphere. Their habitats range from lowlands to mountains and are found as far north as the Arctic Circle and as far south as Mexico.
They are members of the family Rosaceae, the Rose family, and due to a similarity in leaf can be mistaken for their close relative the strawberry. In fact they are sometimes known as the Barren Strawberry. Unfortunately the resemblance stops there as they produce dry inedible fruit. Delicious fruit as well would be just a little too perfect.
Here are a few of my favourites:
Potentilla recta, the Sulphur Cinquefoil, is thought to have been introduced as early as the mid 17th century from mainland Europe. It has hairy leaves with five leaflets and the pale yellow flower spikes reach 50cm tall. The variety ‘Alba’ has white flowers and ‘Warrenii’ has golden blooms. An excellent plant for scrambling between others in the border, popping its sunny flowers through its supporting hosts. Another fine yellow is the Japanese Potentilla megalantha, the Large Flowered Cinquefoil, which has received the Award of Garden Merit from the RHS. This little beauty has egg-yolk yellow flowers which are produced in summer above soft hairy leaves.
The Himalayan native, Potentilla nepalensis, is very variable in colour, and can occur in anything from orange to deepest crimson. The cultivar ‘Miss Wilmott’ is named after the formidable, revolver carrying, 19th century plantswoman, Ellen Wilmott. A very worthy name it is too, with slender stems on which pink flowers with cherry red centres which are held up to 50cm high. A hybrid of nepalensis and Potentilla recta is Potentilla x hopwoodiana. This cinquefoil is more subtly coloured than some of its compatriots, with delicate pink and white blooms and a deep pink centre.
Potentilla atrosanguinea, the Dark Crimson Cinquefoil, is not all its common name would suggest. Indeed it comes deep red, but its saucer-shaped flowers are also sometimes orange or even yellow. The leaves are soft with a toothed edge and composed of three leaflets. Many of the wonderful hybrids available are crosses between this plant and Potentilla nepalensis. The glorious ‘Gibson’s Scarlet’, has semi-double flowers which are as scarlet as scarlet can be. ‘Gloire de Nancy’ is as exotic as she sounds with large semi-double orange/coppery red flowers that continue to shine throughout the summer.
I have saved the best for last. Well my best anyway. Potentilla ‘William Rollisson’. I can’t remember where I first saw this fine gentleman, but I remember they were en masse and quite spectacular. The flowers are semi-double scarlet and orange with a central yellow central boss. An excellent choice for the hot border.
The name ‘potentilla’ comes from the Latin word potens meaning powerful, which is thought to refer to its medicinal properties. The Chinese used some species for making love potions. I’m afraid I haven’t found out which they are yet or I would be using it myself! Potentilla erecta, known as Tormentil, is used for tanning leather and as a red dye.
Generally potentilla enjoy full sun to part shade with a well-drained soil, but are generally unfussy. Vibrant colours are best grown in semi-shade to avoid fading. Alpine varieties prefer gritty and poor soil. Propagation is relatively easy. They come readily from seed but do not expect them to look exactly like the parent plant. That is the fun of growing from seed. Otherwise divide plants in spring or autumn. Shrubby potentillas can be increased by taking cuttings in summer.
Whether you choose the hot herbaceous ‘William Rollisson’ or the more subtle shrubby ‘Elizabeth’, I am convinced you can find a place for a cinquefoil in your garden. The sprawling perennials are excellent in a mixed border and the shrubs provide colour for months on end. Now I have introduced you to a fine selection, there really is no excuse!
By the way, there are already potentilla collections, for more information please visit the Plant Heritage website at nccpg.com.