How to Grow Peas in Australia

Pea (Pisum sativum, also listed as Lathyrus oleraceus) is a cool-season annual in the legume family, Fabaceae. It is grown for sweet shelling peas and for the edible pods of snow peas and sugar snaps. Across most of Australia it fills the beds between summer crops, from autumn to spring, and its roots fix their own nitrogen. Pods picked fresh are at their sweetest, and sowing at the wrong time is where many pea crops fail.

Three mistakes that matter

1. Sowing too late. Peas sown late flower into warm weather, and the flowers can drop in days above about 27°C, so plants crop briefly or not at all. Follow the months in When to plant, and choose a quick dwarf type near the end of a window.
2. Drowning the seed. Pea seed rots in cold, soggy soil before it comes up. Water the drill well once at sowing, then wait until the soil dries a little below the surface before watering again, until shoots appear.
3. Feeding for leaves. Manure, blood and bone and other nitrogen-rich feeds grow soft, lush vines that flower late, set fewer pods and invite mildew and aphids. Peas fix their own nitrogen, so compost at planting and potash at flowering are enough.

When to plant

Pea seed germinates in soil between 8°C and 24°C, and plants crop best when days run between 15°C and 24°C. The vines shrug off frost, but frost damages flowers and young pods, so time sowings to flower in mild weather. Sow a short row every two to three weeks through the window for a longer picking season.

At the warm end of a window, sow a fast dwarf such as 'Sugar Ann', which crops in about eight weeks. At the cold end, raise seed under cover, as in Starting in cells, and plant out once the worst frosts pass.

Site, soil and setup

Peas grow in most soils that drain well and hold plenty of organic matter.

If the soil tests acid, see soil pH explained before liming.

Container growing

Dwarf types suit pots. Use a pot at least 45 cm across, holding roughly 30 to 50 L, filled with premium potting mix. Among the dwarfs, 'Sugar Ann' grows to about 50 cm, and 'Onward' and 'Bon' to about 60 cm. Push in twiggy sticks or a small frame at sowing.

• Water: pots dry out fast, so water whenever the top few centimetres feel dry, and never let them dry out at flowering.
• Feed: nothing before the first true leaves, then seaweed solution at 15 mL per 9 L fortnightly, and liquid potash per label fortnightly from flowering.
• Position: full sun out of strong wind, somewhere the pot can move under cover on frosty nights.

Sowing Seeds

Sow peas straight into the bed, since they resent root disturbance. Some packets hold seed treated with the fungicide thiram, often dyed. Handle it with gloves, wash your hands, and keep it from children, pets and the kitchen. Due to quarantine restrictions and our shipping policy, we cannot send pea seed to Tasmania.

Sowing direct

• Make a drill 20 to 50 mm deep.
• Space seed 5 to 8 cm apart, or about 15 cm for tall climbers, in a single row or a double row 30 cm apart.
• Sow dwarf types in blocks of two or more rows, 40 to 50 cm apart, so they prop each other up.
• Water in once, then as in Three mistakes.
• Seedlings appear in 7 to 21 days.
• Lift young shoots onto the support with small twigs until the tendrils take hold.

Starting in cells

Raise seed under cover when birds, mice or a wet spell threaten a fresh sowing. Sow three seeds to a punnet cell or one to an egg carton cup. For a longer row, sow along a length of gutter filled with seed-raising mix.

• Keep them in a sheltered, sunny spot; egg carton cups fill with roots in about five or six days.
• Harden off (accustom seedlings to sun and wind over about a week) before planting.
• Plant egg carton cups whole, ease punnet plugs out intact, and slide gutter seedlings out, roots and all, at 5 to 6 cm tall.

Care by growth stage

Water at sowing and at flowering decides this crop more than food does. Weeks count from sowing.

If growth stalls in poor soil, a light dose of all-purpose controlled release granular (NPK around 14-5-10) scratched into the soil can help. Nip out the growing tips once climbers reach the top of their support, and mulch with pea straw or compost to keep roots cool.

Companion planting

Good neighbours for peas share the cool season without crowding the trellis, or feed the insects that eat aphids.

Grows well with

• Carrot, parsnip and turnip, slow root crops that stay low beside the rows.
• Spinach, a cool-season leaf that fits the light shade at the foot of a trellis.
• Flowering coriander and sweet alyssum, whose flowers feed ladybirds, hoverflies and parasitic wasps that attack aphids.

Keep apart

• Broad beans in the same bed, since pulses share aphids and the viruses aphids carry.
• Onion, garlic and shallots, a long-standing pairing to avoid; a climbing pea canopy also shades the low bulbs.

Harvesting Pods

Flowers usually open about eight weeks from sowing, pods follow fast, and each type has its own picking sign.

• Pick every few days; pods left to ripen slow new flowering.
• Start at the bottom, where pods form first, and work up the vine.
• Hold the stem and pinch or snip each pod rather than tugging the vine.
• After the last pick, cut plants at ground level and leave the roots to add nitrogen to the soil.

Peas taste sweetest straight after picking, so pick just before cooking. Refrigerate any pods not used straight away. To freeze a surplus, shell it, blanch briefly, cool in iced water and freeze.

Eat snow peas and sugar snaps raw or stir-fried, and steam shelled peas lightly. Snow pea flowers and tendrils are edible too.

Common problems

Gaps in the row. Seed rotted in cold, wet soil, or birds and mice took it. See Three mistakes, and raise seed in cells where birds or mice are bad. Read more

Seedlings grazed overnight. Slugs and snails eat young shoots after dark, worst in damp weather, so hunt them by torchlight and trap them. Read more

Shoots pecked or pulled up. Birds strip and dig young peas, and possums graze them at night. Until plants climb, cover rows with a wire cloche or white, taut netting with mesh too small for a finger. Read more

Flowers but few pods. Heat, dry soil or frost at flowering makes plants shed flowers; see When to plant, and give the flowering soak in Care by growth stage.

Tough, stringy pods. Pods left too long turn tough and starchy, and heat or dry soil makes them stringy, so pick more often.

Silvered seedlings. Leaves rasped silver-white, a mark often mistaken for frost, point to redlegged earth mite (Halotydeus destructor), tiny black mites with red legs. They feed from autumn to spring in southern gardens. Look for them on the leaves in the morning, and pull capeweed and other broadleaf weeds, where they breed.

Pests and diseases

Mildews and blights follow damp weather and dew, while weevils and caterpillars arrive with the flowers.

Powdery mildew (Erysiphe pisi). A white powdery film starts on the oldest leaves, favoured by warm days and cool, dewy nights, and it often arrives as plants finish. Water the soil in the morning, remove the worst leaves and spray 1 part full-cream milk to 10 parts water. Resistant or tolerant types include 'Novella', 'Bon' and 'Willow'. Read more

Downy mildew (Peronospora viciae). Yellow blotches on top of the leaves carry mouse-grey fuzz beneath, in cold, wet weather with nights below 10°C. Pull stunted plants; the rest usually grow away as the weather warms. Read more

Blackspot (Didymella pinodes and related fungi) and bacterial blight (Pseudomonas syringae). Blackspot marks leaves and pods with dark brown spots and runs purplish-black streaks up the lower stem. Bacterial blight starts as small, water-soaked spots that turn brown and papery, often after frost. Both are worst in wet seasons and carry over on old vines and seed, so clear spent plants. Where either has struck before, sow later in the window.

Pea aphid (Acyrthosiphon pisum) and bluegreen aphid (Acyrthosiphon kondoi). Colonies cluster on growing tips and spread viruses such as bean yellow mosaic. Hose them off or use insecticidal soap, and leave the ladybirds, hoverflies and lacewings that feed on them. Read more

Pea weevil (Bruchus pisorum). This small beetle of southern Australia arrives at flowering once spring days reach about 18°C and lays orange-yellow eggs on young pods. Each larva feeds inside a pea, and the adult chews a round exit hole to leave, so pick promptly and never sow holed seed. Read more

Native budworm (Helicoverpa punctigera). Moths fly in from inland each spring, and the caterpillars chew holes in pods and eat the peas. North of Dubbo the look-alike corn earworm (Helicoverpa armigera) joins it, handled the same way: check pods from flowering and pick off small caterpillars.

Prevention first

• Sow fresh, clean seed, never seed saved from a diseased crop.
• Bin diseased vines rather than composting them, and pull self-sown peas.
• Space rows for air flow, and water the soil rather than the leaves.
• Check leaf tips and young pods twice a week from the first flowers.

Tips

1. Peas mostly pollinate themselves, so heirloom varieties usually come true from saved seed; grow one variety at a time for the purest seed. Leave the best pods to dry brown on the vine, then shell them; seed stored cool and dry usually keeps for three years or more.
2. Pinch a few soft shoot tips from young plants for salads and stir-fries; taking too many holds back the crop.
3. Sweet peas (Lathyrus odoratus) are a different plant, grown for scent. Their pods and seeds are toxic, so grow them well away from the vegie rows.