This is the group which includesand everlasting peas. All are hardy.
L. odoratus is the familiar garden, an , producing fragrant from June to September. There are innumerable named varieties in a vast range of colours, but not all are fragrant. They climb by tendrils to a height of up to 2.7 m (9 ft), depending on variety and growing conditions.
Among the perennial species are L. grandiflorus, height 1.5 m (5 ft), producing large purple and pink flowers from June to August; L. latifolius, height 1.8m (6 ft), purplish flowers from June to September; and L. rotundifolius, the Persian everlasting pea, height 1.2m (4 ft), pink flowers from June to August. La thyrus like full sun, and a rich, well-drained soil with some chalk.
General care: Plant25 cm (10 inches) apart, and perennials 45 cm (18 inches) apart. Grow up pea sticks, mesh, trellis, etc. Sweet peas need plenty of nourishment: dig a lot of into the site before planting, and give a weekly of a liquid fertilizer while they are in flower. Annuals and perennials should have the pods removed as they appear, to encourage repeat flowering.
Propagation: Nick the seed coats to encourage germination. Annuals sown in September for the following year give the earliest flowers. Sow in seed boxes of, or direct into the site. Otherwise, in March, in boxes or into the soil. Perennials should be sown in boxes in a cold frame in March, potted on, and planted out in October.
Pests and diseases:and thrips should be controlled with malathion. Lathyrus are subject to a number of fungal diseases. Some cause the to brown and develop white patches and the plant to wilt. Spray with fungicide.
Lathyrus is easily raised from seed. The species latifolius is the best known, and as a climber it grows up to 6 ft high, bearing from July to September sprays of pink or white flowers. Although liking the sun, lathyrus will succeed in partial shade and its leaves and flowers are an asset in any informal arrangement.