Common vetch

How to recognise it

Habit

Annual of 15–90 cm, sprawling or climbing with branched tendrils, with angled, slightly hairy stems.

Leaf

Pinnate, with 3–8 pairs of oblong to narrow leaflets 1–3 cm long, cut off square or slightly notched at the tip with a tiny point, and a branched tendril at the end. The toothed stipules often have a dark spot.

Flower

Large, 1–3 cm, purplish-pink to purple and often two-toned, single or in pairs, almost stalkless in the leaf axils, from May to August.

Fruit/Seed

Pods of 2.5–8 cm, hairless to slightly hairy, brown to black when ripe, with 4–12 round seeds; they twist open.

Roots

A taproot with nodules housing nitrogen-fixing bacteria.

Confused with

Tufted vetch is perennial and has long, one-sided spikes of many bluish-purple flowers. Bush vetch is perennial, grows in half shade and has 2–6 dull purple flowers together on a short stalk. Hairy tare and smooth tare have tiny flowers.

Flowering: May–August · Pruning: June–August

Why grow it?

• Bumblebees, honeybees and solitary bees visit the large purplish-pink flowers from May to August.
• The nectar glands on the stipules, outside the flower, are an extra source of sugar for ants.
• Fixes nitrogen from the air through bacteria in its root nodules: a classic green manure for the vegetable plot.
• The seeds are food for pigeons and other seed-eating birds.
• An old crop plant: sown with oats as fodder for centuries.

Common vetch: where does it grow best?

• In the wild: verges, dykes, grassland, field margins, dunes, railway banks and waste ground.
• Full sun.
• Fairly dry to moderately moist, sandy to loamy soil, not too acid.
• In the garden: in a flowery verge or strip, as green manure in the vegetable plot or among taller plants it can climb.

Goes well with

• Oxeye daisy: White next to purplish-pink on a flowery verge.
• Common knapweed: Purple flower heads for bees and butterflies on the same verge.
• Red clover: Another nitrogen fixer, with pink flowers for bumblebees.
• Common poppy: Red in an annual flower strip.
• Oats: The classic support crop for common vetch as green manure or fodder.

Common vetch: when and how to plant it?

1. Buy seed of native origin from a wild-plant nursery for a verge or flower strip; as green manure you will also find common vetch at ordinary seed merchants.
2. Sow in March–May or August–September on loose soil, 2–3 cm deep, broadcast or in rows 20 cm apart.
3. Soaking the seed in water overnight before sowing speeds up germination.
4. As green manure, cut or dig in the plants when they start to flower; for insects, let some of them flower and set seed.
5. Never dig up plants from the wild; seed is cheap and germinates easily.

Care

Water

Not needed, except after sowing in dry weather.

Feeding

Not needed: it makes its own nitrogen.

Support

Sow it with oats or among taller plants, so the tendrils have something to hold on to and the plant stays upright.

Mowing

On a verge or flower strip: mow in July–August, after it has set seed, and remove the cuttings.

Spreading

Too much? Pull the plants up before the pods ripen; the roots come away easily.

Tip: Sow common vetch in spring with a little oats on a free vegetable bed: the oats give support, the vetch fixes nitrogen and the flowers feed the bumblebees. Cut it when flowering begins, or leave a small strip to flower for the insects.

Pruning and mowing

Pruning months: June–August.

When: In July–August, after the seed has set; as green manure in June, when flowering begins.

How:

• In a flower strip: only mow once most of the pods are ripe, leave the cuttings for a few days and then remove them.
• As green manure: cut the plants when flowering begins and dig them in shallowly or leave them as mulch.
• Leave the roots in the soil: as they break down, the nitrogen from the nodules becomes available to the next crop.

Caution: Do not eat the pods or seeds, even though they look like peas.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Ripens in July–August; the pods twist open and shoot out the seeds. Sow in spring or late summer, or let the plant self-seed.

Common vetch: how does it get through the winter?

Hardy to −15 °C: protect young plants.

• Annual: the plant dies after setting seed.
• Plants sown in late summer overwinter as young plants; in severe winters they are sometimes killed by frost.
• The seed overwinters in the soil and germinates in spring.

Diseases and pests

• Aphids: Black bean aphids on the shoot tips in May–June. Ladybirds and hoverfly larvae usually keep them in check.
• Flopping: Without support it falls over and rots on wet soil. Sow it with oats or among other plants.
• Powdery mildew and rust: Appear in late summer. Not a problem for an annual; clear diseased plants after flowering.
• Seedlings in the vegetable plot: If you let it set seed, it comes back among the vegetables. Cut it or dig it in before the pods ripen.

Through the year

• March: Sow as green manure or in a flower strip.
• April: Young plants; the tendrils look for support.
• May: First purplish-pink flowers; bumblebees arrive.
• June: Full flower. Cut and dig in green manure.
• July: Flowers and ripe pods; mow after the seed has set.
• August: Last flowers and mowing. Sow as green manure after harvesting a crop.
• September: Sowing is still possible; young plants overwinter.
• October: The green manure covers bare soil.

Did you know?

• Sativa means ‘sown’ or ‘cultivated’: the plant was already sown as a fodder crop in ancient times.
• The small dark spot on the stipules is a nectar gland outside the flower; ants come to collect sugar from it.
• When ripe pods burst, they twist like a corkscrew and fling the seeds some distance.