Red Oxalis corymbosa is a popular ornamental plant, valued for its striking foliage and delicate blooms. This perennial herb offers unique visual appeal with its vibrant color and clover-like leaves. Its charming flowers enhance its decorative value, making it a favored choice for indoor and outdoor cultivation.
Characteristics and Identification
Oxalis corymbosa, also known as Pink Shamrock or Lilac Oxalis, is a perennial herb from South America. It grows without a true stem, with leaves emerging from an underground bulb system. The plant features trifoliate leaves, each composed of three heart-shaped leaflets. These leaves often fold downwards as dusk approaches.
While many Oxalis corymbosa varieties have green foliage, “Red Oxalis corymbosa” is valued for its deep red or purple leaf coloration. This vibrant pigmentation provides striking contrast. Funnel-shaped flowers, typically pink or mauve, emerge with five petals. These flowers are borne in clusters atop slender stalks, usually blooming in spring and summer.
Cultivating Red Oxalis Corymbosa
Light
Oxalis corymbosa thrives in bright, indirect light, which helps maintain its vibrant foliage color. It tolerates some direct morning sun, especially in cooler climates, but intense afternoon sun can scorch its leaves. Indoors, an east or west-facing window provides ample light. Insufficient light leads to leggy growth and diminished foliage color.
Soil
A well-draining soil mix is important for Oxalis corymbosa, preventing waterlogging that harms its bulbous roots. A slightly acidic to neutral pH is preferred for optimal nutrient uptake. Incorporating perlite or coarse sand into a potting mix enhances drainage. For outdoor planting, ensure the garden bed has good drainage, amending heavy clay soils with organic matter.
Watering
Consistent moisture benefits Oxalis corymbosa, but the soil should never become waterlogged. Allow the top inch of soil to dry out between waterings to prevent root rot. The frequency of watering depends on environmental factors like temperature and humidity. During its active growing season, more frequent watering is necessary compared to dormant periods.
Temperature and Humidity
Oxalis corymbosa prefers mild temperatures. While it tolerates some fluctuations, extreme heat or cold can stress the plant. High humidity is not a strict requirement; average household humidity levels are sufficient. Protecting the plant from drafts and sudden temperature changes ensures its well-being.
Fertilization
During the active growing season (spring through fall), Oxalis corymbosa benefits from light fertilization. Apply a balanced liquid fertilizer, diluted to half strength, every couple of months. Avoid over-fertilizing, as this can lead to nutrient burn and harm the plant’s root system. Reduce or stop fertilization entirely during the plant’s winter dormancy.
Propagation Techniques
Propagating Red Oxalis corymbosa is most effective through the division of its underground bulbs or rhizomes. This process is best done during the plant’s dormant period, typically in winter. Gently unpot the plant and carefully separate the bulb clusters by hand. Each healthy bulb or clump can form a new plant.
Replant separated bulbs into individual pots with a well-draining potting mix. Plant them shallowly, ensuring the bulb top is just at or slightly below the soil surface. After planting, provide light watering to settle the soil. New growth emerges as temperatures rise, indicating successful propagation.
Managing Common Challenges
Oxalis corymbosa is a robust plant, but it can face challenges like spider mites and aphids. Regular foliage inspection, especially the undersides of leaves, aids early detection. If pests are found, a gentle spray of insecticidal soap or neem oil effectively manages infestations. Good air circulation also deters pests.
Overwatering frequently causes root rot, manifesting as wilting or yellowing leaves despite moist soil. Allow the soil to dry slightly between waterings to prevent this. Oxalis corymbosa naturally enters dormancy, often due to extreme heat or cold, during which its foliage may die back. During dormancy, reduce watering significantly until new growth signals its return. Leggy growth, characterized by stretched stems and sparse leaves, indicates insufficient light and can be addressed by moving the plant to a brighter location.
Red Oxalis Corymbosa in the Landscape
Red Oxalis corymbosa adds color to various landscape designs. It performs well as a container plant, showcasing its vibrant foliage on patios or balconies. Its spreading habit makes it suitable as a groundcover, creating a dense carpet of colorful leaves. It also thrives as an indoor houseplant, especially in colder winters.
While appealing, Oxalis corymbosa can be a vigorous spreader in certain climates. Its prolific bulb production allows effective spreading, potentially leading to it being perceived as a weed. To manage its outdoor spread, plant it in contained areas or use physical barriers. Responsible planting ensures its beauty is enjoyed without unintended proliferation.