How to grow and care for Oxalis triangularis

Oxalis triangularis, also known as false shamrock, is an eye-catching bulbous perennial that makes an excellent and long-lived house plant. Bold, dramatic foliage in shades of dark purple to wine-red creates a striking contrast to blush-white flowers borne in summer. The leaves are three-lobed, hence the name of shamrock which it resembles, though is not actually related to. Oxalis triangularis is native to from Brazil. Its leaves have extra fascination because they open during the day and close at night.

Oxalis triangularis is borderline hardy, surviving in temperatures no lower than -3°C, so is suited to outdoor growing only in the mildest areas of the UK. Oxalis triangularis goes dormant in winter and regrows the following spring.

Grow Oxalis triangularis from bulbs and plant in spring or buy ready-grown plants in summer. Grow in pots or in the ground, either indoors all year or outside for the summer only. Keep watered and feed regularly during the growing season.

Site in sun or partial shade outside. Indoors, place in bright light but out of direct sunlight which can scorch the leaves. A cool to warm room is best at a temperature between 15-21֯C. Avoid draughts and wide fluctuations in temperature.

Buying dormant bulbs in late winter is the most economical way to grow Oxalis triangularis. Plant bulbs pointed-end up, 5cm deep, in pots of peat-free, multi-purpose potting compost. Or plant in fertile, free-draining soil outside, in late spring.

As growth develops, increase watering so that the compost stays evenly moist while taking care not to overwater. Ensure good drainage indoors by