Windowbox Woodsorrel: A Charming Non-Native Ground Cover
Meet the windowbox woodsorrel (Oxalis rubra), a petite perennial that’s been making itself at home in gardens across the southern United States. This South American native has quietly established itself as a naturalized resident, bringing delicate pink blooms and distinctive three-part leaves to landscapes from Texas to Virginia.
What Is Windowbox Woodsorrel?
Windowbox woodsorrel is a low-growing forb—essentially a non-woody perennial plant that lacks significant woody tissue above ground. Its botanical name, Oxalis rubra, gives away its rosy character, as rubra means red or reddish. You might also encounter it listed under its synonym, Oxalis articulata ssp. rubra.
This charming plant produces small, five-petaled flowers in shades of pink to reddish-pink, creating a delicate carpet of color when in bloom. The distinctive shamrock-like leaves, arranged in groups of three heart-shaped leaflets, fold up at night or during cloudy weather—a quirky characteristic that adds to its appeal.
Where Does It Grow?
Originally from South America, particularly Argentina, Uruguay, and southern Brazil, windowbox woodsorrel has adapted well to life in the United States. It now grows wild in twelve states: Alabama, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Texas, and Virginia.
Should You Plant Windowbox Woodsorrel?
The decision to plant windowbox woodsorrel comes down to your gardening goals and philosophy. As a non-native species that reproduces spontaneously and persists without human intervention, it sits in that gray area between welcome garden guest and potential concern.
The Case for Planting It
- Attractive pink flowers provide seasonal color
- Low-maintenance once established
- Excellent for containers and windowboxes (hence the name!)
- Thrives in rock gardens and as ground cover
- Attracts small pollinators like bees
- Interesting leaf movement adds garden intrigue
Considerations Against
- Non-native status means it doesn’t support local ecosystems as well as native plants
- May self-seed and spread beyond intended areas
- Could potentially compete with native wildflowers
Growing Windowbox Woodsorrel Successfully
If you decide to grow windowbox woodsorrel, it’s refreshingly easy to please. This adaptable plant thrives in USDA hardiness zones 7-10, making it suitable for most of the southern United States where it’s already naturalized.
Ideal Growing Conditions
- Light: Full sun to partial shade
- Soil: Well-draining soil is essential
- Water: Moderate water needs; allow soil to dry between waterings
- Temperature: Hardy in zones 7-10
Planting and Care Tips
- Plant bulbs in fall for spring blooms
- Space plants 6-8 inches apart for ground cover effect
- Perfect for containers, rock gardens, and borders
- May go dormant during extreme summer heat—this is normal
- Requires minimal fertilization
- Deadhead spent flowers to prevent excessive self-seeding
Native Alternatives to Consider
If you love the idea of low-growing plants with interesting foliage but prefer supporting native ecosystems, consider these alternatives:
- Wild ginger (Asarum canadense) for shaded areas
- Wild strawberry (Fragaria virginiana) for sunny spots
- Native violets (Viola species) for similar small flowers
- Partridgeberry (Mitchella repens) for evergreen ground cover
The Bottom Line
Windowbox woodsorrel occupies an interesting niche in the gardening world. While it’s not native to North America, it’s also not considered invasive or noxious. It’s simply a naturalized resident that some gardeners appreciate for its charm and easy-care nature. Whether you choose to plant it depends on your personal gardening philosophy and whether you prioritize native species support over ornamental appeal.
If you do decide to grow it, you’ll find windowbox woodsorrel to be a delightful, low-maintenance addition that brings subtle beauty to containers, rock gardens, and border edges. Just remember to deadhead those flowers if you want to keep it from wandering too far from home!
