Pink tulips with blue periwinkles by Val Bourne
Periwinkles are ground cover plants that provide good winter foliage and early flower. They are most useful in wilder areas of the garden where they will smother weeds, or clothe difficult slopes.
They are not for those with smaller gardens as they send our runners which root where they land, rather as some strawberries do. This makes them too invasive to be included in ordinary borders where choice bulbs and woodlanders are planted. However they can flatter borders containing mature trees and shrubs and the flowers, which normally appear in March, are very good for early bees. Deer seem to leave them alone too.
Vincas, commonly known as periwinkles, normally have green leaves and single flowers in either purple, blue, pink or white. However there are double-flowered forms and variegated forms too so the choice is wide, although they all send out runners. The Lesser Periwinkle, Vinca minor, offers the greatest choice of colours and flower type.
Vincas vary in height. Taller varieties are listed under Vinca major (roughly reaching 18in/45 cm) and shorter ones (which reach 4in/10cm on average) are listed under V. minor. There is also an earlier-flowering species called V. difformis which needs more shelter to do well.
The shorter forms send out far more runners and effectively cover whole areas in a netting of stems. Taller periwinkles tend to send out a few long runners, about two feet in length, and these dip to the soil and root - sometimes just where you don’t want them. Plant them in areas where spreading and travelling are desirable and don’t be fooled into thinking that the shorter vincas are less invasive. It’s quite the reverse. Vincas are invasive and they’ve become a real problem in North America and New Zealand.
Margery Fish, the famous cottage gardener from East Lambrook Manor, writing in Ground Cover Plants, lists them under Rampers. However I grow some along my stone walls in sunless positions where little else thrives.
How to grow periwinkles
These are bombproof plants that tolerate shade or light-shade in a variety of soils including acid and alkaline. Vincas also make good container plants - particularly the small-leaved Vinca minor forms. Vincas will always travel towards better light though.
In winter the foliage can get shabby and forms of Vinca major and V. minor are hardy enough to be sheared off to encourage fresh spring growth. Do not shear off V. difformis however: it is a little too tender as it comes from the Western Mediterranean.
Keep a vigilant eye for unwanted runners and pull any in the wrong place up.