If you want an easy houseplant that produces plenty of pretty flowers and lots of drama. Oxalis, commonly called shamrock plant, should be on your list. Oxalis in any color can’t wait to start blooming in late winter. Purple shamrocks have pinkish flowers, with white flowers more common on green shamrocks. Happy plants will bloom intermittently year round. Indoor plants: Oxalis Plant!
Indoor plants: Oxalis Plant
When you open a bag of oxalis bulbs you may be surprised. No, we didn’t ship you a handful of pudgy sticks or undernourished pinecones. Honest. Iron Cross bulbs look pretty normal, like typical little bulbs. These funny looking bulbs will produce foliage and flowers in just 8-10 weeks.
Really. This is just one of those horticultural leaps of faith you’ll have to trust us on the first time around. After that, you’ll be in the know and can pass a few pudgy sticks on to friends and watch their reactions.
Features of the Plant
Velvet Oxalis regnellii is one of the prized black plants. Usually one prefixes a mention of that group with “so-called,” because most of its members. While admittedly dark, are a long way from being a true black, being, instead, more of a dark purple. But Velvet can just as legitimately be called a “black shamrock” as a “purple shamrock.”
It is that dark. Yes, there is some purple in it, and how closely it approaches true black depends on lighting and other growing conditions. But along with black mondo grass, this is one of the few plants that one can be comfortable designating as “black,” without much qualification.
They require bright or direct sunlight supplemented with a cool indoor temperature of ~15 degrees Celsius (~60 degrees Fahrenheit). They can tolerate higher indoor temperatures but will go into dormancy prematurely and/or begin to take on a “tired” appearance if temperatures go above 27 degrees Celsius (~80 degrees Fahrenheit) for prolonged periods of time.
Use average potting soil with good drainage and allow the surface soil to dry out between waterings. Mature False Shamrock plants are cut back to the soil every 3–5 years in early summer or during the dormancy period. Young plants are cut back to the soil every year in early summer or during the dormancy period, until they reach maturity.
Ideally soak the soil and then allow the top inch or so to dry out before watering again. Although irregular and random watering is not a problem here. In fact the plant can often go months without adverse effects especially when it’s cooler.
However if it’s very warm or it sits in a very bright spot you will need to make an effort to water regularly, because if things get too dry the plant will die back.
If you want to propagate your oxalis triangularis you’ll find it’s best to do this towards the end of it’s dormant period (I would do this after 2 weeks of dormancy to be sure of timing).
The bulb will have to be removed from the pot and then you may remove the small bulb offsets which are re-potted to produce new plants. Be patient with the new plants and expect them to appear a little later than the main plant.
Oxalis triangularis bulbs look like small, immature pinecones. When planting a container for indoors, go ahead and crowd your bulbs, spacing them just an inch apart for a full look fast. Just poke the bulbs into the soil – any way up is right. Water lightly just once every couple of weeks until new growth appears. In about 6 weeks from planting, your new purple shamrocks will begin to appear, and will fill in to become lush and full soon after.
Weekly watering should be light. Too much water will send the plant back into dormancy. Indoors, keep your oxalis triangularis in a sunny spot. You will find the deep purple foliage really brings out the vibrant green of other plants, and the color contrast makes your other houseplants seem to glow with health.