Oxalis Triangularis ‘Purple Shamrock’

Commonly called false shamrock, is a species of perennial plant in the family Oxalidaceae. It is native to several countries in southern South America. This woodsorrel is typically grown as a houseplant but can be grown outside in USDA climate zones 8a–11, preferably in light shade. The deep maroon leaves are trifoliate, like species in the clover genus Trifolium which are commonly called shamrock, hence the name “false shamrock”. An interesting feature is that the leaves close like an umbrella at night or when disturbed or if kept under harsh sunlight. The white or pale pink five-petalled flowers also close at night.

• Botanical Name: Oxalis Triangularis

• Common Names: Purple Shamrock

Here’s how to care for Oxalis triangularis:

1. Light: Provide bright, indirect light for your Purple Shamrock. Avoid direct sunlight, especially during the hot afternoon hours, as it can scorch the delicate leaves. A location near a north- or east-facing window is ideal.
2. Temperature: Purple Shamrocks prefer temperatures between 60°F to 75°F (15°C to 24°C). They can tolerate slightly cooler temperatures but should be protected from frost and freezing temperatures.
3. Watering: Keep the soil evenly moist but not waterlogged. Allow the top inch (2.5 cm) of soil to dry out slightly between waterings, then water thoroughly, ensuring that excess water drains away. Avoid letting the plant sit in water, as it can lead to root rot.
4. Soil: Use a well-draining potting mix with good aeration. A mix formulated for African violets or general-purpose potting soil amended with perlite or sand works well. Repot the plant annually in spring if it outgrows its container.
5. Humidity: Purple Shamrocks prefer moderate to high humidity levels. If the air in your home is dry, mist the plant regularly or place a humidifier nearby. Alternatively, you can set the pot on a tray filled with pebbles and water to increase humidity around the plant.
6. Fertilizing: Feed your Purple Shamrock with a balanced liquid fertilizer diluted to half strength every 4 to 6 weeks during the growing season (spring and summer). Reduce or stop fertilizing during the fall and winter months when growth slows down.
7. Pruning: Remove any yellow or dead leaves as needed to maintain the plant’s appearance. Pinch back leggy stems to encourage bushier growth.
8. Dormancy: Purple Shamrocks may enter a period of dormancy in fall or winter, during which they may drop their leaves. This is normal behavior, and the plant will typically rebound when conditions improve in spring.
9. Propagation: Purple Shamrocks can be propagated easily from bulb divisions or stem cuttings. Divide overcrowded clumps of bulbs in spring or take stem cuttings and root them in moist potting soil.
10. Pests and Diseases: Purple Shamrocks are generally pest-resistant but may occasionally attract aphids, spider mites, or mealybugs. Inspect the plant regularly for signs of pests, and treat infestations promptly with insecticidal soap or neem oil.
11. Toxicity: Oxalis plants contain oxalic acid, which can be toxic if ingested in large quantities. Keep Purple Shamrocks out of reach of children and pets, and wash your hands after handling the plant.

With proper care, your Purple Shamrock can thrive indoors, providing you with its lovely foliage and occasional delicate flowers.