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Vicia villosa

woolly vetch

Attracts Pollinators Attracts Butterflies

SunFull Sun – Part Shade

Overview

Vicia villosa is a vigorous densely hairy scrambling annual or winter annual vine in the family Fabaceae reaching 24-60 inches (60-150 cm) tall and 24-48 inches (60-120 cm) wide, climbing by branched terminal tendrils and often forming dense tangled masses over supporting vegetation. The entire plant is covered in soft woolly spreading hairs, which is the main identification feature and the source of both common names. Stems are angular and densely villous (woolly). Leaves are pinnately compound with 12-20 oblong leaflets 0.4-0.8 inch (10-20 mm) long. Flowers are violet-purple to blue, 0.5-0.8 inch (12-20 mm) long, papilionaceous, bicolored (the banner is darker violet-purple, the wings are lighter with white tips), in dense one-sided drooping racemes of 10-30 flowers on long axillary peduncles. The dense one-sided raceme is diagnostic. Fruit is a flattened legume pod 0.8-1.2 inches (20-30 mm) long, smooth, turning brown to black, and carrying 2-8 seeds. Nitrogen-fixing via Rhizobium spp. root nodules. A single plant produces 500-2,000 seeds. The species is the dominant legume cover crop by planted acreage in the United States and also occurs as a roadside and field edge weed.

Native Range

Vicia villosa is native to Europe and western Asia, on roadsides, field edges, waste ground, and cultivated fields from sea level to approximately 6,000 feet (1,800 m). Widely planted as a winter cover crop across North America. Naturalized throughout the Pacific Northwest both from intentional plantings and as an escaped weed.

Suggested Uses

Used as the woolly dense-racemed member of the four-species Vicia spp. identification exercise. The densely hairy stems support a tactile identification exercise. The one-sided raceme architecture contrasts with the symmetric racemes of V. americana. The species is the dominant legume cover crop by planted acreage in the United States; nitrogen fixation rates (60-200 lb N/acre) are studied in sustainable agriculture. The roll-crimp termination method is a primary teaching example in no-till cover-crop management.

How to Identify

Separated from the other Vicia spp. species in the collection by the dense woolly pubescence covering the entire plant versus the smooth or sparsely hairy stems of the other three species. Separated from V. sativa by the dense one-sided raceme of 10-30 flowers on a long peduncle versus the 1-2 sessile flowers of V. sativa, by the bicolored violet-and-white flowers versus the uniformly reddish-purple flowers of V. sativa, and by the woolly versus smooth stems. Separated from V. americana by the woolly stems, by the larger racemes (10-30 versus 3-9 flowers), and by the annual versus perennial habit.

Appearance

Size & Dimensions

Height2' - 5'

Width/Spread2' - 4'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~4 weeks

Spring Summer

Dense one-sided drooping racemes of 10-30 violet-purple bicolored flowers 0.5-0.8 inch (12-20 mm) long on long axillary peduncles, borne May through July over 3-4 weeks. Pollinated by bees. Pods mature 4-6 weeks after flowering. In the Pacific Northwest the dense purple racemes are conspicuous along roadsides and in cover-crop fields in June.

Detailed Descriptions

Flower Description

Violet-purple to blue; bicolored with white wing tips; papilionaceous; in dense one-sided drooping racemes of 10-30 flowers; May-July

Foliage Description

Medium green; pinnately compound with 12-20 oblong leaflets; entire plant covered in soft woolly spreading hairs; deciduous

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5(Neutral)

357912

Soil Types

loam sand silt clay

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Care & Maintenance

Care Guide

In areas where unwanted, mowing or cutting before seed set prevents spread. The vigorous scrambling habit can smother fences, shrubs, and adjacent crops if unmanaged. In agricultural settings, V. villosa is the dominant legume cover crop by planted acreage in the United States and fixes 60-200 pounds of nitrogen per acre (67-224 kg/ha). Winter-seeded stands are mowed or incorporated at flowering in spring. The hard seed coat produces a persistent soil seed bank; volunteer seedlings appear for several years after planting. Some cattle can develop a potentially fatal dermatitis from grazing mature V. villosa forage.

Pruning

Pruning does not apply in a weed context. Vines are mowed or pulled before seed set. In cover-crop settings, stands are mowed or roll-crimped at peak flowering for maximum nitrogen fixation before incorporation.