When to sow Sweet pea?

Sweet peas thrive in full sun or partial shade and prefer a rich, moisture-retentive loam. Before planting, dig over the soil thoroughly and incorporate plenty of well-rotted compost or manure to improve structure and fertility—sweet peas are hungry feeders and reward good preparation. Choose a spot sheltered from strong winds but with good air circulation. You can sow sweet peas in two main windows: in October or November for an early start, or in March and April for later flowering. Autumn sowing produces stronger plants that flower earlier, but requires protection over winter in a cold frame or unheated greenhouse. For spring sowing, wait until the soil is workable and frost risk is diminishing. Sow seeds about 2.5 cm deep, either directly into the ground or in deep pots or root trainers to minimise root disturbance. If starting in pots, harden off plants gradually before transplanting. Space plants 25 cm apart in the ground. Sweet peas are vigorous climbers reaching 100–250 cm, so install sturdy supports—canes, netting, obelisks, or a wigwam of bamboo—at planting time. Plant out seedlings carefully to avoid damaging the roots, firming soil gently around the base. Water in well after planting to settle roots, and apply a 5 cm layer of mulch around (but not touching) the stems to retain moisture and suppress weeds. Pinch out the growing tip when plants are about 10 cm tall to encourage bushier, more floriferous growth from the base.