Purple wood sorrel, with its striking foliage and delicate blooms, is a common sight in many landscapes, whether as a cultivated ornamental or a spontaneous garden guest. Understanding its characteristics, uses, and management strategies can help gardeners and homeowners appreciate or control its presence.
What is Purple Wood Sorrel
Purple wood sorrel (Oxalis triangularis) is a perennial plant distinguished by its deep purple, clover-like leaves. Each leaf consists of three triangular leaflets that fold down at night or in dim light and open with brightness, a characteristic known as nyctinasty or photonasty. Delicate, pale pink to white, five-petaled flowers bloom atop slender stems from spring through early fall.
A member of the Oxalidaceae family, it is also referred to by various common names, including false shamrock, purple shamrock, and love plant. Oxalis triangularis originates from South America, particularly Brazil, where it thrives in tropical climates. While cherished globally as an ornamental, its ability to spread vigorously from underground rhizomes or tubers can also make it a persistent garden weed.
Purple Wood Sorrel as an Edible Plant
Purple wood sorrel offers a distinctive tart, lemony flavor, making it a culinary addition. The leaves, flowers, and tubers are edible. They can be added to salads, used as a garnish, or steeped for beverages.
Consume purple wood sorrel in moderation due to its oxalic acid content. This acid gives sorrel its tartness. While generally safe in small quantities, excessive consumption can be problematic for individuals prone to kidney stones or with kidney conditions, as oxalic acid can interfere with calcium absorption. Enjoy this plant as a flavorful accent, not a staple food.
Cultivating Purple Wood Sorrel
To grow purple wood sorrel as a decorative plant, provide optimal conditions. It thrives in bright, indirect light; filtered sunlight near a window is ideal. Too much direct sun can scorch its leaves, while insufficient light may result in leggy growth.
Well-draining soil is important, and a general-purpose potting mix amended with perlite or sand improves drainage. Keep the soil consistently moist but never waterlogged, as excess moisture can lead to root rot. Water every one to two weeks, allowing the top inch or two of soil to dry between waterings.
Purple wood sorrel prefers moderate room temperatures, typically between 60°F and 75°F (15°C and 24°C), and benefits from average humidity levels. Propagation is commonly done from its small, underground rhizomes or corms, which resemble tiny pinecones. Plant these about 1 to 2 inches deep in well-draining soil; new growth typically appears within a few weeks.
Controlling Purple Wood Sorrel
While Oxalis triangularis is a desirable ornamental, it can become an unwanted weed in garden beds due to its prolific bulb production. Its ability to spread rapidly from underground corms makes eradication challenging. Manual removal is an effective control method, but it requires diligence.
Carefully dig out the entire plant, including all its small bulbs, as any remaining bulbs can quickly sprout new plants. Mulching can suppress its growth by blocking light and creating a barrier. A thick layer of organic mulch can reduce new plant emergence and make manual removal easier.
For severe infestation, targeted herbicide application may be a last resort, following product instructions carefully. However, the plant’s underground corms can make chemical control less effective than with other weeds, often requiring repeat applications. Consistent effort is necessary to manage this plant when not desired.