How to Grow and Care for Oxalis Triangularis (False Shamrock)
Oxalis triangularis, commonly known as the false shamrock, is a stunning bulbous perennial that adds a bold touch to any indoor or outdoor space. With its deep purple to burgundy-red foliage and delicate blush-white flowers, this long-lived plant is a favorite among gardeners and houseplant enthusiasts. Native to Brazil, Oxalis triangularis features fascinating leaves that open during the day and close at night, adding a dynamic element to its charm.
Although borderline hardy, it can survive temperatures as low as -3°C, making it suitable for outdoor growth only in mild climates. During winter, it enters dormancy and regrows in the spring.
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How to Grow Oxalis Triangularis
You can grow Oxalis triangularis from bulbs planted in spring or purchase fully grown plants in summer. It thrives in pots or directly in the ground, flourishing indoors year-round or outdoors during warmer months.
- Keep the plant well-watered and feed it regularly during the growing season.
Where to Grow Oxalis Triangularis
- Outdoors: Choose a spot with sun or partial shade.
- Indoors: Place in bright, indirect light to prevent leaf scorching. It prefers temperatures between 15-21°C. Avoid exposure to draughts and temperature fluctuations.
How to Plant Oxalis Triangularis
The most cost-effective way to grow Oxalis triangularis is by purchasing dormant bulbs in late winter.
Steps for Planting:
- Bulbs: Plant pointed-end up, 5cm deep, in pots with peat-free, multi-purpose compost.
- Outdoor Planting: Use fertile, well-draining soil in late spring.
How to Care for Oxalis Triangularis
- Watering: As the plant grows, increase watering to keep the soil evenly moist. Avoid overwatering, as it can lead to root rot.
- Drainage: Ensure proper drainage by placing pots on saucers with gravel. If growing in outdoor containers, elevate the pots slightly to allow excess water to escape.
- Feeding: Apply a high-potassium liquid fertilizer every 3-4 weeks during the growing season.
- Winter Dormancy: In autumn, the plant begins to die back. Gradually reduce watering, keeping the soil almost dry over winter. Resume watering in early spring to encourage new growth.
- Cold Protection: If grown outdoors in pots, move them to a greenhouse, conservatory, or sheltered porch for the winter months.
How to Propagate Oxalis Triangularis
Propagate by division in late winter while the plant is dormant:
- Separate clumps of established plants into smaller sections, ensuring each has bulbs.
- Replant at the same depth as they were previously growing.
Pests and Diseases
Oxalis triangularis is generally low-maintenance and resistant to pests when provided with proper care. Overwatering is the primary concern, as it can cause root rot and weaken the plant.
Buying Oxalis Triangularis
- The standard Oxalis triangularis variety is widely available.
- Specialty varieties with pink or yellow flowers are rarer and usually sold as potted plants.
- Bulbs can be ordered in winter or early spring from online nurseries and bulb suppliers.
- Before purchasing, inspect bulbs for signs of mold and plants for any damage or disease.
With the right care, Oxalis triangularis will reward you with its unique beauty season after season. Whether grown indoors or outdoors, its striking foliage and charming flowers make it a standout addition to any plant collection!
FAQs About Growing and Caring for Oxalis Triangularis
How often should I water Oxalis triangularis?
- Water regularly during the growing season, keeping the soil evenly moist but not soggy. Reduce watering in autumn as the plant enters dormancy, keeping the soil almost dry over winter.
Can Oxalis triangularis be grown outdoors?
- Yes, it can be grown outdoors in mild climates where temperatures don’t drop below -3°C. Otherwise, it’s best grown in pots that can be moved indoors during winter.
Why do the leaves of my Oxalis triangularis open and close?
- This plant has a natural nyctinastic movement, meaning its leaves open during the day and close at night in response to light changes.
How do I propagate Oxalis triangularis?
- You can propagate it by dividing the bulbs while the plant is dormant in late winter. Replant the smaller bulb clusters at the same depth as before.
What is the best location for Oxalis triangularis indoors?
- Place it in bright, indirect light, avoiding direct sunlight that can scorch the leaves. It thrives in temperatures between 15-21°C with minimal exposure to drafts or sudden temperature changes.
