Sweet Peas, Still Climbing (gouache style)

The sweet pea, Lathyrus odoratus, is an annual climber native to Sicily and southern Italy. It pulls itself upwards with tendrils, modified leaflets that wrap round any support they touch. Victorian breeders made it a florist's favourite, and the large, frilly Spencer types appeared in the early 1900s. Older grandiflora varieties have smaller flowers, but they're often the most strongly scented. Don't eat the seeds: unlike garden peas, they're toxic.

There are two sowing windows. Seed sown in October or November and overwintered in a cold frame gives sturdier plants and earlier flowers, while a February or March sowing under cover still does well. Use deep pots or root trainers, as the roots run long. Pinch out the growing tip once seedlings have a few pairs of leaves to encourage side shoots, then plant out in April or May against canes, netting or a wigwam. Pick every few days and remove any pods, or flowering soon tails off.

Pink, ivory and purple flowers climb through a pale blush ground in this picture, with no cane or net in view. The title, Sweet Peas, Still Climbing, catches the plant mid-growth, still reaching up and still in flower. It's the stage every grower tries to stretch out for as long as possible, by picking and then picking again.