Cow Vetch

Cow Vetch: A Perennial Climbing Herb for North American Gardens

Meet cow vetch (Vicia cracca tenuifolia), a perennial climbing plant that has quietly made itself at home across various regions of North America. While not native to our continent, this hardy herbaceous perennial has established populations from the Pacific Northwest to the Atlantic provinces of Canada, and even found its way to Hawaii.

What Exactly Is Cow Vetch?

Cow vetch belongs to the legume family and is classified as a forb herb – essentially a vascular plant that lacks significant woody tissue above ground. Think of it as a climbing cousin to your garden peas, complete with the family’s characteristic ability to fix nitrogen in the soil through specialized root bacteria.

This particular variety is known by several botanical synonyms, including Vicia cracca var. angustissima and Vicia tenuifolia, which might explain why you’ll sometimes see it listed under different names in plant databases.

Where You’ll Find It Growing

Cow vetch has established populations across a surprisingly diverse range of locations. You can find it growing in Ontario, Prince Edward Island, Quebec, New York, Washington, Wisconsin, and Hawaii. This wide distribution suggests it’s quite adaptable to different climate conditions.

Should You Grow Cow Vetch in Your Garden?

As a non-native species that reproduces spontaneously in the wild, cow vetch falls into that middle ground where it’s neither aggressively invasive nor particularly rare. Here are some considerations:

Potential Benefits:

• As a legume, it can help improve soil nitrogen content
• Perennial nature means it comes back year after year
• Climbing habit can provide vertical interest
• Hardy across various climate zones

Things to Consider:

• May self-seed and spread beyond intended areas
• Limited information available about wildlife benefits
• Not native, so won’t support local ecosystems as effectively as native alternatives

Native Alternatives Worth Considering

If you’re looking for native climbing legumes, consider these alternatives that will better support local wildlife and ecosystems:

• American groundnut (Apios americana) – edible tubers and fragrant flowers
• Wild lupine (Lupinus perennis) – supports endangered Karner blue butterfly
• Partridge pea (Chamaecrista fasciculata) – bright yellow flowers loved by native bees

Growing Cow Vetch Successfully

If you decide to grow cow vetch, here’s what to keep in mind based on its growth characteristics and distribution:

Growing Conditions:

• Likely prefers full sun to partial shade
• As a legume, probably tolerates poor soils well
• Provide support structures for its climbing habit
• Hardy in multiple USDA zones based on its wide distribution

Care Tips:

• Monitor for self-seeding to prevent unwanted spread
• May benefit from occasional pruning to keep growth in check
• Water during establishment, but likely drought-tolerant once established

The Bottom Line

Cow vetch is one of those plants that sits quietly in the background of our naturalized landscapes. While it’s not going to win any awards for showiness and isn’t the best choice for supporting native wildlife, it’s also not causing major ecological problems. If you’re drawn to its climbing habit and nitrogen-fixing abilities, just be mindful of its potential to self-seed and consider whether a native alternative might better serve your garden’s goals.

Remember, every plant choice is an opportunity to support local ecosystems – so when in doubt, go native!