Advice
RHS Help & Advice
Sowing and training sweet peas
Timing
In milder areas sow during October. In colder areas sow late March/April.
Sowing
Seeds are usually sown in deep pots of seed compost, spacing them 2-3cm (1in) apart. Alternatively they can be sown in root trainers or grow tubes (deep containers for individual seeds).
Chip the hard seed coat opposite the 'eye' (small, round
scar) (right) using a sharp penknife, to help moisture entry and germination.
Don't soak the seeds as they are prone to rotting.
Sow seeds 1cm (0.5in) deep, water in, cover with glass and keep at about 15°C (59°F). Once seedlings have emerged the glass can be removed and they can be transferred to a cold frame.
Winter care
Keep the frame opened as much as possible to harden the seedlings. Protect from heavier frosts and heavy rain. Tender spring-raised seedlings need careful hardening off in a cold frame to acclimatise them to outdoor temperatures.
Seedlings
When the seedlings are about 3.5 cm (1.5in) high plant out, into individual containers, such as 6cm (3in) pots, containing seedling or potting compost.
Pinch out the growing tips of autumn-sown seedlings when about 10cm (4in) high to encourage branching. Pinch spring-sown seedlings just above the first pair of leaves.
Planting out
Plant out overwintered plants in mid-spring, those spring-sown in late spring. Choose a sunny, open, well-drained, humus-rich site.
Training
Training plants as cordons produces top quality blooms. This method is used by professional growers. Cordons are trained as single-stemmed plants to individual canes, with side-shoots and tendrils removed so that all the plant's energies are diverted into flower production. For domestic purposes use traditional pea sticks or canes, allowing plants to scramble over the supports. For a regular supply of blooms cut flowers frequently, before they have time to produce seed pods.
Training cordon sweet peas
For information on this topic visit the BBC gardening website