Vegetable · Fabaceae
Field Pea
Pisum sativum subsp. arvense
Give its tendrils a grain to grip, and the field pea builds your soil and feeds it nitrogen for free.
Full sun
Every 5–10 days
60–90 days
USDA 6–8
Overview
Field pea is the working cousin of the garden pea, the very same species raised for its trailing vines rather than its sweet pods. It sits in the legume family and reaches back to the old grain fields of Europe and the Near East. Growers keep it as a cover crop and green manure, where it feeds the soil instead of the table, though the young shoots and peas remain good eating.
What it does below the surface is the real prize. Working with soil bacteria the way other legumes do, it pulls nitrogen straight out of the air and fixes it into the ground, leaving the bed richer than before. Mow or till the crop at full bloom and the next planting draws on that stored nitrogen.
Those vines are long, soft, and weak, so a stand on its own sags and packs down into a flat mat. That is why field pea almost always goes in with a small-grain nurse crop such as oats or rye for the slender tendrils to grip. Suit the type to your winters, hand it cool weather and steady water, and it takes care of the rest.
Care
The short version: full sun and cool weather, steady moisture because it hates heat and drought, well-drained soil of moderate fertility, and a small-grain nurse crop for the tendrils to climb. Inoculate the seed and skip the nitrogen, since the plant makes its own.
Light
Field pea reaches for full sun, though it tolerates a touch of partial shade. As a cool-season crop it answers more to temperature than to raw light, so it does best when the days run bright while the air stays cool.
Water
Hold the soil evenly moist, since this is a cool-season legume with little tolerance for drought. Heat is what it minds most, and once the temperature climbs past 90°F (32°C) the flowers blast and seed yield falls off. Steady moisture through cool weather is what carries the crop.
Soil
It takes root in well-drained clay or heavy loam of moderate fertility and does fine on loamy sands as well. Aim for a pH between 6.0 and 7.5. Drainage is the rule that counts, because soggy ground invites the root rots that dog peas.
Temperature
This is a cold-tolerant cool-season crop, and the hardy winter types take down to about 10°F (-12°C) with only minor injury. The danger sits at the warm end, where anything above 90°F (32°C) blasts the flowers and cuts the seed set.
Humidity
Plain outdoor air suits it, so there is no number to chase. Airflow and drainage matter far more, since damp, crowded growth is what brings on mildew and the leaf and stem blights.
Feeding
This is where field pea pulls its weight: as a nitrogen-fixing legume it needs little to no nitrogen fertilizer. Coat the seed with Rhizobium at planting so the nodules can form, and add phosphorus or potassium only when a soil test reads low.
Pruning
There is no pruning to do. Instead, the whole crop is terminated at or before full bloom, mowed, tilled, rolled, or left to winterkill, which is the point where it holds the most nitrogen for the soil.
Repotting
none
Size & spacing
12–47 in (30–120 cm) tall
When to plant
Field pea lives on cool weather and wants no part of summer heat. In mild zones, sow Austrian winter pea from mid-August into September so it rides out the winter, and in colder areas hold off and sow spring field peas the moment the ground can be worked. Either path, the flowers open in spring, and that bloom is your signal to terminate the crop for the most nitrogen.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Not started indoors; direct-sown in the field
- Plant: Sow Austrian winter pea from mid-August to mid-September to overwinter in mild zones (roughly USDA 6-8); sow spring field peas as early as the soil can be worked in colder areas
- Harvest: Pink-and-purple to white pea flowers in spring; terminate at or before full bloom for maximum nitrogen
Hardiness
USDA hardiness zones: 6–8
Temperature: down to -23°C
Troubleshooting
Nearly all field pea trouble comes down to three things: vines with nothing to grip, winters harder than the type can bear, and soil tired from tight rotations. Read the early signs below, match what you find on the plant, and act while it still pays off.
Soft vines sag to the soil and rot
The stems run long, soft, and thin, so a pea stand left by itself tends to lodge, folding down into a low mat where the bottom growth yellows and rots against the ground. Slip in a small-grain nurse crop, oats, rye, or barley, and the curling tendrils have something to grip. Cut the pea seeding rate by roughly a quarter and the grain by about a third, and the planting holds its height.
Fix:
- Grow the peas with a small-grain nurse crop such as oats, rye, wheat, barley, or triticale for the tendrils to climb
- Reduce the pea seeding rate by about one quarter and the grain by about one third in the mix
Winter pea browns and folds after a hard freeze
What you are seeing is winterkill, and it strikes Austrian winter pea pushed past its range or sown too late to bulk up first. The hardy strains take about 10°F (-12°C) with little more than nicked foliage, but a stretch of cold near 18°F (-8°C) on bare ground, with no snow to blanket them, ends the stand. In cold zones, let the browned vines lie as a winter-killed mulch, or go with spring-sown field peas instead.
Fix:
- In cold zones treat winterkill as a feature and use it as a winter-killed mulch, or switch to spring-sown field peas
- Choose winter-hardy cultivars and plant early enough to reach 6 to 8 inches tall before soil freezes
Thin, pale plants with bare roots
Drop the seed into ground that has gone years without peas and the right Rhizobium may be missing, so almost no nitrogen-fixing nodules form and the plants come up yellow-green and slight. Lift a few roots and look for firm, pink, active nodules to settle it. Re-coat the seed with fresh inoculant just before you sow, then put it in again.
Fix:
- Re-inoculate and re-seed with fresh, viable Rhizobium inoculant applied immediately before seeding
Yellowing, wilt, rots, dark spots, or white dust
Tight rotations and wet soil open the door to a run of pea diseases, from Sclerotinia and root rots to Ascochyta blight and powdery mildew, while pea aphids cluster on the shoots and carry viruses along. Browned, rotted roots mark root rot, dark lesions across stems and leaves mark Ascochyta, and a fine white fuzz on the foliage marks mildew. Pull peas out of the rotation for a few years, sow on well-drained ground, and reach for resistant cultivars and clean, treated seed.
Fix:
- Rotate out of peas for several years and avoid wet, poorly drained ground
- Use resistant or tolerant cultivars and clean, treated seed
- Scout for pea aphids and manage where thresholds are reached
Toxicity
Good news on this front, since field pea is the same species as the garden pea and carries no toxins. The shoots, pods, and peas are safe food for people and pets, and the vines make solid forage. The one thing to watch is heavy grazing of leafy growth by cattle, sheep, and goats, which can bring on bloat rather than any poisoning.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Nothing about a pea shoot threatens a cat, so a stray nibble of the soft foliage does no harm. Most cats walk right past the leaves anyway.
Dogs None
A field pea holds nothing that hurts a dog. Cooked peas show up as a sound ingredient in many pet foods.
Horses Safe
Horses graze the vines with no problem, which is part of why the crop is raised as forage. Bring them onto any rich new pasture slowly, as with any lush green feed.
Rabbits Safe
Those tender shoots and leaves are good rabbit food. Serve them next to hay rather than as the entire meal.
Livestock Mild
Cattle, sheep, and goats do well on pea forage, with one catch: grazing heavy, leafy growth can trigger bloat, a buildup of digestive gas rather than any poisoning. Bring animals onto the stand gradually and mix in grass to keep their guts steady.
Birds Safe
Chickens and other yard birds gladly take the peas and the greens. Wild and farmed birds alike treat the seed as good feed.
People Safe
Being the same species as the garden pea, the young pods, peas, and shoots are good eating. Gather them while still tender for the sweetest flavor.
Immature pods, peas, and tender shoots are edible. Like other legumes, lush pea forage can cause bloat in ruminant livestock if grazed heavily, but it is not poisonous to pets or people.
Varieties
Field peas split into fall winter types and spring types, and which one fits comes down mostly to how cold your winters get. Here are the ones you will run across most.
Austrian Winter Pea
A cold-hardy fall type whose two-toned purple and pink blooms sit above small, dark speckled seeds; sown in late summer to carry through winter in mild zones.
Whistler
A winter-type forage and cover-crop field pea bred for cold-hardy fall planting.
40-10
A widely grown winter forage line used as a cover crop and green manure.
Spring forage field peas
Spring-sown types for colder regions where a fall-sown winter pea would simply winterkill.
Companions
Field pea grows best beside the small grains that hold its weak vines up, which is why nearly every cover-crop mix pairs the two.
Plant near
Oats: A small-grain nurse crop gives the weak pea vines something to climb on and adds biomass, reducing lodging.
Cereal rye: Provides upright support for the climbing tendrils and pairs well in fall-sown cover-crop mixes.
Barley: Serves as a nurse grain that supports the vines and balances the pea's nitrogen with a carbon-rich companion.
How to propagate
Field pea comes up from seed and nothing else, dropped straight into the ground rather than started in pots. The knack lies less in the sowing and more in matching the seed to the right inoculant and a grain to lean on.
SeedEasy
Fall (mid-August to mid-September) for Austrian winter pea in mild zones; early spring for field peas in colder areas · Emerges in about 1-2 weeks; reaches usable size within several weeks to a couple of months
Seed is the only way in, dropped straight into the ground and never raised in pots. In mild zones, sow Austrian winter pea from mid-August to mid-September; in colder areas, sow field peas the moment spring soil can be worked. Dust the seed with the right Rhizobium inoculant just before it goes down, and pair it with a small-grain nurse crop so the tendrils have support. The seedlings push through in about 1 to 2 weeks and grow to usable size within several weeks to a couple of months.
Myths
The field pea is some other plant, not the edible garden pea.
Both are one and the same species, Pisum sativum. The field pea is merely the forage subspecies arvense, chosen for strong vining cover-crop growth rather than sweet shelling. Its tender shoots and peas are perfectly good to eat; the plant is just raised to build soil and feed stock.