Purple shamrock (Oxalis triangularis) care

Other · easy to keep

Purple shamrock (Oxalis triangularis) wants bright indirect light with some direct sun. Water it every 6 days. Keep lightly damp while in leaf. When it dies back, stop watering entirely until new shoots appear. Pot it in free-draining compost with perlite. A balanced feed at half strength monthly while in leaf, and repot once a year. Humidity: room humidity is fine. Toxic to cats and dogs in quantity — the leaves are high in oxalic acid.

Purple shamrock: triangular deep-purple leaflets on thin stalks that fold down at night and open again in the morning, with small pale pink flowers. It grows from little scaly rhizomes and dies back completely once a year — which looks like death and isn't. Stop watering, wait a month, and it returns thicker.

Quick facts

Water: Water every 6 days. Keep lightly damp while in leaf. When it dies back, stop watering entirely until new shoots appear.
Light: Bright indirect light with some direct sun.
Humidity: Room humidity is fine.
Soil: Free-draining compost with perlite.
Feeding: A balanced feed at half strength monthly while in leaf.
Repotting: Repot once a year.
Toxic to pets: Toxic to cats and dogs in quantity — the leaves are high in oxalic acid. A nibble is harmless; a mouthful is not.
Difficulty: Easy.
Mature size: 20–30 cm tall.
Native to: Brazil.

Watering a Purple shamrock

Water every 6 days. Keep lightly damp while in leaf. When it dies back, stop watering entirely until new shoots appear.

That cadence is the one PlantParlour sets for this species when you name it, and it is deliberately on the cautious side — a plant that asks a day early is safer than one that asks a day late. Log each watering and the reminder moves with the plant rather than with the calendar.

Light

Bright indirect light with a little direct sun. The purple deepens in brighter light; in shade the leaves stretch and pale.

Humidity and temperature

Room humidity is fine. Central heating in winter is what turns a comfortable room into a dry one, and it is the usual reason an established plant suddenly browns at the edges or picks up spider mites.

Soil and potting

Ordinary compost with perlite. It grows from small scaly rhizomes just under the surface.

Feeding

A balanced feed at half strength monthly while in leaf. Stop feeding in autumn and start again when you see new growth in spring — feeding a plant that isn't growing just builds up salts in the pot.

Repotting

Repot once a year. Every second spring, or whenever the pot fills with rhizomes. Divide at the same time.

Common problems

Dies back to nothing in late summer
Dormancy, and completely normal.

Fix: Stop watering, leave the pot somewhere cool for a month or two, then start again — it comes back thicker.
Leaves folding down
Normal. It folds at night and in strong sun.

Fix: Nothing to fix.
Pale stretched stems
Not enough light.

Fix: Move it brighter.

Propagation

Divide the rhizomes at repotting; each scaly piece makes a new plant.

A cutting taken in PlantParlour keeps its link to the plant it came from, so a propagation years later still traces back to the mother plant — which is the point if you ever sell or trade it.

Toxicity and safety

Toxic to cats and dogs in quantity — the leaves are high in oxalic acid. A nibble is harmless; a mouthful is not.

Questions people ask

How often should you water a Purple shamrock?

Water every 6 days as a starting point — that is the cadence PlantParlour sets for Oxalis triangularis. Keep lightly damp while in leaf. When it dies back, stop watering entirely until new shoots appear. Light, pot size and the time of year all move that number, so treat it as a reminder to go and check rather than a rule.

How much light does a Purple shamrock need?