Few houseplants have a party trick quite like the Purple Shamrock. Its deep purple, triangular leaflets open and close with the light. (The process is actually called Nyctinasty- it's a type of plant movement that is related to night and day). The unfurling by day and folding down at night gives visibly changes through the day.
Also known as False Shamrock, Oxalis triangularis is dramatic, characterful, and easy to live with. It's one of our top-selling plants for a good reason.
Here's everything you need to know.
Perfect for
The plant lover who wants living, moving drama on a windowsill.
Rich purple foliage and delicate pale flowers make it a striking choice for anyone who wants something a little theatrical, without a lot of fuss.
Did you know?
The Purple Shamrock naturally goes dormant, sometimes several times a year when grown indoors, and this is completely normal. Oxalis are sold either as a growing plant (that's what you buy from us) or as bulbs to be planted in February or March.
When your plant dies back, it isn't dying; like other bulbs, it's simply resting before it bounces back.
Oxalis can be grown outdoors in a partially shaded spot over spring and summer. They look great in window boxes.
Natural Habitat
Oxalis triangularis is native to southern South America, where it grows from tubers and creeps along the ground. This tuberous, ground-dwelling nature is exactly why it goes dormant and regrows so readily, and why it propagates so easily from its offsets.
Light
Purple Shamrocks need bright, indirect light, and a little gentle morning or evening sun is fine. If the plant doesn't get enough light, it will become leggy and stretched. When it goes dormant in autumn or winter, move it to a cooler, darker spot, then as soon as you see new shoots emerging, bring it back into a brighter spot and start watering again.
Water
During the growing period, Oxalis are wonderfully expressive about their needs: the stems become droopy and the leaves start to wilt when they're thirsty. Allow the top inch of soil to dry out before watering, as the plant likes to be moist but never soggy. It does well in average room humidity and thrives in normal house temperatures of around 15 to 21°C, suffering above 25°C, which can tip it into dormancy.
Feed with a diluted houseplant fertiliser (half the suggested strength) every couple of weeks during the growing season, such as our Fortifying House Plant Tonic.
Propagation
This is where the Purple Shamrock really shines. It can be easily propagated by separating the offsets and repotting the little bulbs into different pots. The best time to do this is a couple of weeks after the plant has gone dormant. It only needs repotting every few years, so combine propagation with a repot into a well-draining houseplant soil like our Houseplant Potting Mix.
A little extra - reading the leaves
The Purple Shamrock tells you exactly how it's doing. Yellow spots can signal rust disease, white patches point to powdery mildew, and dry or crispy leaves usually mean sunburn. Leggy stems are a cry for more light, while yellowing leaves can mean old age, overwatering, or the start of dormancy. Droopy stems mean it's either thirsty or getting ready to rest.
You can regularly find Purple Shamrock, including the lovely deep purple 'Mijke' in our plant shop.
