Purple Shamrock Oxalis Bulbs

Oxalis triangularis — Purple Shamrock. Three triangles to a leaf, all of them a deep saturated purple, held on thin stems above the pot. In good light the colour reads almost black-violet; in shade it fades toward green, which is your plant telling you where it wants to be.

The pale pink flowers come in waves through summer, a few at a time, and the whole plant shuts its leaves like folded hands each evening and opens them again in the morning.

It is small — 6 to 12 inches — which makes it the rare dramatic plant that fits on a windowsill, and the reason it has stayed in cultivation for well over a century.

What you get

• Deep purple, three-lobed leaves on 6–12 in stems.
• Pale pink flowers opening in flushes from late spring.
• Folds its leaves at night — the trait that makes it a talking point.
• Grows happily indoors in a bright window, or outdoors in zones 8–11.
• Dormant corms that re-sprout reliably, season after season.

How to grow it

• Plant: 1–2 in / 3–5 cm deep, pointed end up, 3–4 in apart in a pot with drainage. Soak the corms for an hour first — they wake up faster.
• Light: bright, indirect light or a few hours of morning sun. Strong light keeps the purple deep; deep shade turns the leaves green.
• Water: keep evenly moist while growing, then let the top inch dry between waterings. Never leave the pot standing in water.
• Temperature: 60–75°F indoors. Hardy outdoors in USDA zones 8–11; elsewhere grow it in a pot and bring it in before frost.
• Dormancy: the leaves die back every few months — that is normal, not death. Stop watering for 4–6 weeks, then start again and it regrows from the corms.

Shipped dormant as graded corms, cleaned and ready to plant. Dispatch in 5–7 working days. Leaf colour and flower shade vary with light, season and the age of the corm — the first flush after planting is usually the darkest. Keep away from cats and dogs: oxalis is high in oxalic acid and is not pet-safe if chewed.