How to grow peas

You can buy a wide choice of pea varieties as seed in garden centres and from online seed suppliers. Many also sell young plants in spring and early summer, ready for immediate planting.

Sowing under cover in February or March allows you to get an early start, particularly if your soil is cold and wet, when seeds may fail to germinate or may rot outdoors. You can also sow in autumn and keep plants indoors over winter, for planting out in early spring. Indoor sowing can protect the seeds from being eaten by mice.

Fill deep modular trays, small pots or cardboard tubes with multi-purpose compost. Sow up to three seeds per pot, or one per narrow tube or module, inserting them about 5cm (2in) deep.

Alternatively, sow peas along a length of guttering filled with multi-purpose compost, spacing seeds about 7.5cm (3in) apart in a double row. This makes transplanting outside easy, as you have ready-made rows that can simply be slid into a trench.

Indoor-sown peas can be planted out in March and April, once they’re about 20cm (8in) tall – see Planting out, below.

The main outdoor sowing season is from March to June. Pea seeds won’t germinate in cold conditions, so wait until the soil reaches about 10°C (50°F). If spring is slow to arrive, warm the soil with polythene sheeting or a cloche before sowing, then protect the seedlings with cloches or fleece. However, peas do generally prefer cooler weather and grow well in a cool spring. Avoid sowing in very damp soil though, as the seeds may rot.

For taller varieties, sow seeds 7.5cm (3in) apart in either a single row, or a double row with 30cm (1ft) between them (for the supports). Generous spacing between the rows makes these large plants easier to support and improves air circulation, which deters powdery mildew.

Shorter varieties need less space between rows, as a few twiggy sticks should suffice for support. They are usually sown in a triple row in a flat-bottomed trench. Use a draw hoe to make the trench, 5cm (2in) deep and 15cm (6in) wide. Sow three rows using the full width, staggering the seeds so they’re about 7.5cm (3in) apart. Cover with soil, then lightly firm and water well.

If sowing additional sets of rows, space them at a distance equal to the height of the variety you are growing.

To get harvests throughout the summer, either sow several batches of an early variety every few weeks, or make one sowing of both early and maincrop varieties, as they will mature at different times.

Protect seedlings from slugs and snails, especially in damp conditions, and from pigeons.

You can also sow pea seeds specifically for harvesting the tender shoot tips or ‘pea shoots’, to use in salads. Sow at any time indoors, into seedtrays filled with multi-purpose compost, inserting seeds 2.5cm (1in) deep and spacing them 2.5cm (1in) apart.

Keep well watered and in bright light, and harvest the young plants in three to four weeks, when 10–15cm (4–6in) tall. If you cut the stems about 2.5cm (1in) from the base, they may re-sprout to provide a second harvest.

You can plant indoor-raised or bought plants outside from March onwards, once they’re about 20cm (8in) tall.

First, harden off the seedlings to acclimatise them to outdoor conditions. Do this by placing them in a cold frame or under a cloche for a week. Alternatively, take them outdoors during the day, then bring in at night for a week, and the following week leave them out in a sheltered spot all day and night.

Plant into prepared ground (see above), about 7.5cm (3in) apart, taking care not to disturb the roots. Firm in gently and water well. Arrange in rows as described in Sowing outdoors, above – planting shorter varieties in a triple row, and taller varieties in either a single row or a double row with 30cm between them to allow space for supports.

If the plants were grown in a length of guttering (see Sowing indoors, above), simply dig out a shallow trench of similar dimensions to the guttering, then gently slide the compost and plants into it, with minimum disturbance to the roots. Firm in gently, then water well.

If planting another set of rows, allow plenty of space between, for good air circulation – ideally equal to the expected height of the plants (check the seed packet for details).

Once young pea plants are settled in and growing strongly, they shouldn’t need watering, except in particularly dry spells. But do give them a good watering once they start to flower, and again two weeks later to help the pods to swell. While cropping, check the soil moisture at root level regularly and water if necessary.

Regular watering during cropping also helps to deter powdery mildew, but take care not to wet the leaves – water at the base of the plants, not over them.

Add a thick mulch of garden compost around the plants to help stop the soil drying out in summer and to deter weeds.

Most peas, apart from dwarf cultivars, need supports to scramble up. Put this in place soon after the seedlings appear or when planting out:

• For taller varieties, use netting or chicken wire attached to posts or bamboo canes. Some varieties can grow up to 1.8m (6ft) tall and become top heavy, so make sure the supports are suitably tall and sturdy, especially in windy sites.
• For smaller varieties, use pea sticks (twiggy stems) inserted between the plants