Perennial species such as Lathyrus latifolius come back year after year, but mostly lack fragrance and there are fewer to choose from.
Most sweet pea varieties are annuals. Perennial sweet peas: Perennial sweet peas come back year after year. You do not need to replant them after the growing season ends, and they will continue to grow for a longer period of time.
Sow perennials into pots in a cold frame in spring for planting out in autumn. If necessary, soak seed overnight before sowing, to hasten propagation. Pinch out top shoots when 6in (150mm) high to encourage side shoots.. . . . .364011234072!]0000000000000009783314145290!]
