Spiny Restharrow: A Thorny European Beauty in American Gardens
Meet spiny restharrow (Ononis spinosa), a prickly perennial that’s been quietly making itself at home in parts of the United States. This European native brings a touch of Old World charm to American landscapes, though it comes with some thorny considerations for gardeners to weigh.
What Is Spiny Restharrow?
Spiny restharrow is a perennial shrub that typically grows as a multi-stemmed woody plant, usually staying under 13-16 feet in height. True to its name, this plant is armed with thorns along its stems, making it a somewhat defensive garden resident. The plant produces small, pea-like flowers in shades of pink to purple that bloom throughout the growing season, creating a delicate contrast to its spiky demeanor.
You might also encounter this plant listed under its botanical synonym, Ononis campestris, in older gardening references or plant databases.
Where Does Spiny Restharrow Grow?
Originally from Europe, particularly the Mediterranean regions and Western Europe, spiny restharrow has established populations in several U.S. states. Currently, you can find it growing wild in Illinois, Maryland, New York, and Pennsylvania, where it reproduces on its own without human intervention.
Garden Appeal and Landscape Role
Despite its thorny nature, spiny restharrow offers several attractive qualities for gardeners. Its small, colorful flowers provide nectar for bees and butterflies, making it a pollinator-friendly choice. The plant works well as ground cover or for erosion control, particularly in naturalized areas where a more wild, untamed look is desired.
This shrub thrives in full sun locations and well-drained soils, showing impressive drought tolerance once established. It’s particularly suited for:
- Wild or naturalized gardens
- Coastal landscapes
- Areas with poor soil conditions
- Low-maintenance landscape designs
Growing Spiny Restharrow Successfully
If you’re considering adding spiny restharrow to your landscape, it’s generally hardy in USDA zones 5-8. This makes it suitable for much of the temperate United States, though it performs best in areas with conditions similar to its Mediterranean origins.
Growing tips for success:
- Plant in full sun for best flowering
- Ensure well-draining soil to prevent root rot
- Water regularly during establishment, then reduce watering
- Tolerates poor, rocky, or sandy soils
- Minimal fertilization needed
- May self-seed in favorable conditions
Should You Plant Spiny Restharrow?
As a non-native species, spiny restharrow presents a mixed bag for American gardeners. While it’s not currently listed as invasive or noxious, it’s worth considering native alternatives that provide similar benefits while supporting local ecosystems.
Consider these native alternatives instead:
- Wild lupine (Lupinus perennis) for similar pea-like flowers
- New Jersey tea (Ceanothus americanus) for pollinator appeal
- Wild bergamot (Monarda fistulosa) for butterfly attraction
If you do choose to grow spiny restharrow, be mindful of its potential to self-seed and monitor its spread in your garden. The thorny stems also make it less suitable for high-traffic areas or gardens frequently used by children and pets.
The Bottom Line
Spiny restharrow offers drought tolerance, pollinator benefits, and low-maintenance growing requirements that appeal to many gardeners. However, as responsible gardeners, we should weigh these benefits against the value of supporting native plant communities. While this European transplant isn’t causing major ecological concerns, choosing native alternatives often provides greater benefits to local wildlife and ecosystems while achieving similar landscape goals.
