One of the rare plants with practically black leaves is the purple shamrock (Oxalis triangularis), sometimes known as the fake shamrock. The true color of its leaves is dark purple. Triangular in shape, the leaves often appear in clusters of three. They close like an umbrella at night or on overcast days but unfurl in the morning sun. The small flowers on this plant range in color from white to pastel pink or lavender. It’s ideal to plant purple shamrock in the spring, and once it’s established, it makes a lovely houseplant. I’ve always adored Oxalis triangularis, sometimes known as the Purple Shamrock Plant, but I’ve put off buying one because I already have so many houseplants. I saw these plants when picking out annuals for my garden one day, and I decided I liked them so much that I would plant them every year. Of course not! After observing how well they did in a pot outside, I made the final decision to bring them back inside and treat them like a houseplant. Do you want to know where and how to plant an Oxalis triangularis garden? If you read on, I’ll explain everything in full.
The Care of Purple Shamrocks
Within its hardiness range, the purple shamrock is a low-maintenance plant that thrives in both the ground and pots. Watering the plant whenever the soil begins to dry out and placing it in a sunny location are the two most important factors in ensuring the plant’s health. In addition, you need to prepare to regularly feed your shamrock during the growing season.
Keep in mind that purple shamrocks are dormant in the summer and only actively grow and bloom from fall to spring. Even though this probably won’t happen every year, there are still steps you should take to ensure the best possible outcome for your houseplants in the event it does. The plants’ foliage deteriorates when they are dormant. When this happens, you should stop fertilizing and watering the plant until the problem is resolved. When you notice fresh growth in your plant, you can go back to your regular watering and fertilizing schedule.
Preventative Maintenance for Oxalis Triangularis
Here’s some background info you should know before I dive into how to tend to your potted Oxalis triangularis. (If you don’t care, skip this paragraph, but I promise it gets better.)
The False Shamrock Plant is common. As to why it’s a “fake” shamrock if you will. Clover, a member of the Trifolium genus, bears a striking resemblance to these leaves. The Oxalis genus includes the so-called “False Shamrock” plant.
It’s an oxalis triangularis if you must know.
Family Oxalidaceae, sometimes known as the wood sorrel family, contains the plant Oxalis triangularis.
The leaves of this plant are trifoliate (compound leaf with 3 leaflets). The triangular leaves can be either simple green or dark purple, like the ones on my plant, depending on the cultivar.
The five-petaled, tiny trumpet-shaped flowers can be in a variety of hues. There are varieties with white blooms and even yellow ones; mine has lavender or purple ones.
Did you know that although Oxalis triangularis is native to a few countries in South America—among them Brazil—it is hardy in zones 6–11?
In these climates, Oxalis triangularis can be grown as a beautiful perennial that spreads rapidly and provides a lot of visual variety in the garden.
Although I haven’t given it a try, I understand that these perennials may thrive in certain climates. Check out my blog post, Pushing Your Hardiness Zone, to increase your chances of success if you reside in a slightly less-than-ideal location for this plant.
Purple shamrock (Oxalis triangularis)
Amazing time-lapse recordings have been made highlighting the fascinating phenomenon of this plant’s capacity to close its leaves (and blooms) at night and open them again during the day.
It is known as “photo nasty behavior” when this occurs. That’s a funny word, right? You may witness the photo nasty behavior of Oxalis triangularis in a nice video on Wikipedia. (The word “photo nasty” never ceases to make me giggle.)
If you’re worried that your Oxalis triangularis is suddenly dying, you’re probably fine; I’ll explain what to do in a while. These plants grow from tubers and have a dormancy period.
Not only are the leaves attractive, but they may also be eaten!
Eat them in moderation; they’re high in oxalic acid.
The oxalic acid presence makes it taste bitter and sour, hence the name. Too much will prevent your body from absorbing calcium, but a little bit won’t hurt.
Don’t go munching on a big salad made entirely of these greens. Add some garnish, it won’t hurt.
Numerous accounts have been gathered of families who have cared for these plants for more than a century. Let’s hear it for the heirloom houseplant!
What Is The Best Way To Take Care Of Indoor Oxalis?
Let me go through some of the fundamentals of care and growth conditions, and then I’ll go over how to plant the corms if you decide to go that route.
The amount of light that this plant receives inside is crucial.
If you’re growing these plants indoors, they need bright, direct light. This plant needs at least half a day’s worth of sun, but ideally a full day’s worth, depending on your latitude and the intensity of the sunlight and artificial light.
How bushy or slender is your Oxalis triangularis? It’s probably not getting enough light if it is. In many situations, I find direct lighting indoors to be preferable. A plant will continue to expand, but not to the same extent. Bringing your plant into fuller sunlight, or at least partial sunlight, will cause it to produce more leaves and expand. If you want the greatest results, put the plant in direct sunlight near a window.
These plants can even survive in full sun indoors, provided that you water them frequently enough to account for the increased rate of evaporation.
Allow me to say a few things about transferring your plant to an outdoor setting. Please exercise caution when relocating any indoor plant outdoors, even if it is one of the few that does well with direct sunshine. A plant that has been kept in indirect light indoors should not be exposed to direct sunlight at once.
Your vegetation will be destroyed if you proceed in this manner. That includes the ones that require a lot of sunlight. It is important to harden your plants off before moving them from home to outdoors.
Read More: Best Maranta Plant in Bangalore
To prevent leaf burn, you must gradually adapt your plants to brighter outdoor circumstances. Read my blog post on safely transitioning houseplants to outside conditions for more details on this process.
Allow the top inch or two of soil (2.5-5cm), depending on the size of your container, to dry out before watering again; this plant prefers slightly wet circumstances. Oxalis triangularis requires a thorough soaking when watered, with excess water allowed to drain through the drainage hole. Always utilize containers with drainage holes to ensure your plants thrive. We do not want root rot, which can develop if there are no drainage holes. Don’t let them become completely dry, especially for extended periods, as you can trigger a dormancy period. The period of dormancy will happen anyhow, but we’ll get to that in a minute. If you maintain these indoors in a damp environment, the corms may rot and the plant will die.
When the plant is actively growing, I prefer to fertilize it very lightly every time I water it. I’ve recently moved to use Dyna-Gro Grow as my go-to fertilizer for all of my houseplants.
In addition to providing all of the macro and micronutrients that plants require, this product is urea-free, which is another reason why I enjoy using it. Only one fertilizer is needed for indoor plants, and this one works wonderfully for all of them. When using this fertilizer, I have seen excellent outcomes.
The lower the temperature, the better these plants will grow. Oxalis plants thrive between 60 and 75 degrees Fahrenheit (16-24C).
If the temperature outside stays above 80 degrees Fahrenheit (27 degrees Celsius), the plant may shut down and enter a dormant state.
As soon as it’s warm enough in the spring, I move my plant outside. By leaving it outside, I extend the growing season until at least November. After that, I stop watering it and store it someplace cool and dark. Because of this, it will be put into a state of hibernation.
In the coming weeks, it will enter a state of dormancy and its leaves will dry up. Keeping an eye on it is a good idea because after a few weeks it may begin to show signs of development again. If you see it beginning to grow again, move it to a sunny window sill right away.
Once it emerged from its winter slumber, here is how my plant looked:
Don’t worry if you haven’t seen any progress after four to six weeks. Get rid of the wilted foliage, set the pot in a sunny window, and begin watering to encourage new growth.
When brought indoors, new leaves will start developing at a rapid rate because of the ideal environment.
This plant thrives in a mixture of three parts of all-purpose potting soil to one part perlite. To be honest, I use this mixture for most of my plants.
What reason is my Oxalis wilting?
If you notice that your Oxalis triangularis is starting to appear a bit worse for wear, but nothing else has changed in its care, it may be naturally entering its dormancy period.
It’s not going to die any time soon. Reframe this as a chance to revive your plant. You should get used to the dormant phase since it is typical.
Your Oxalis may begin to droop after the main growing season each year. The leaves may close up during the day.
The conclusion of the dormant phase signals the time to bring the plant back inside, back to a sunny window, and back to light watering. You can increase your watering frequency after you notice new growth. But wait to water heavily until you notice fresh growth.
Before new growth appears, keep it on the dry side but don’t forget to water it.
It’s also an excellent time to divide the tubers and start as many new plants as you’d like in brand-new containers. After the tubers have gone dormant, you can divide them into as many pieces as you like.
Insured Pests & Infections
It’s never convenient to deal with pests or diseases. The great thing about your Oxalis triangularis plant is that you can let it go dormant and start growing new leaves from scratch if it ever gets infested with any pests or diseases and you don’t want to cure it.
However, if you want to know how to care for your plant, continue reading.
Pests like spider mites should be eliminated as soon as possible to prevent the infestation from spreading. Although spider mites are minuscule in size, their delicate webs will be visible on the plant’s leaves and you’ll likely find them hiding in crevices beneath the plant’s surface.
Painful Feeding Crustaceans
A further annoyance is mealy bugs. They’ll look like clumps of white cotton (which will stand out beautifully against the deep purple leaves).
If you have mealy bugs, I recommend using insecticidal soap.
Leaves affected by powdery mildew, a fungal disease, will develop cloudy white spots. It grows on dry leaves in dim, humid, and chilly circumstances.
Having stale air around can also make things worse.
Take care of your plant by applying a natural fungicide. Another option is to add one tablespoon of baking soda and half a teaspoon of dish soap to one gallon of water and spray it on the plant.
Extremely frustrating annoyance is how thrips are best described. Unlike other plants, thrips are less of a problem on Oxalis triangularis.
Why? Because, as I explained before, you can put it to sleep. The reset button can be readily set to its original state.
Thrips infested one of my outdoor Oxalis triangularis plants. The leaf has many cuts.
Insecticidal soap can be sprayed on the plant, although it will be tough to get every part of the plant. The foliage in my plants is a tangled mess.
It’s nearly not worth it unless you can thoroughly spray the entire plant.
Here’s what you should do instead if you want to rid your Oxalis of thrips:
Put your plant in isolation, stop watering it, and let it go dormant so that it can die back to the ground.
Throw away the dried-out plants once they have lost all their moisture.
Saturate the ground with a systemic pesticide. Any thrips nymphs that have fallen to the ground will be eliminated in this way. The Bonide Systemic Insect Control for Houseplants is a product that I find to be effective.
Get back to your regular schedule of feeding, watering, etc.
Check out my post on my blog for additional information on thrips and how to handle them in your houseplants.
Instructions For Propagation Of Oxalis Triangularis Corms
Rather than purchasing a live plant, you may grow your own from corms by ordering them online and then planting them in containers. All you need is a few moments of your time, and it’s done!
A plant in a 4-inch container was my starting point; I bought it from the annual section of a nursery.
Plant your tubers in a deep, wide pot, giving them space to grow by a factor of 1 to 1 1/2 inches (2.5 to 4cm). If you want a complete plant, the tubers can’t be too far apart.
Vertically, with the narrower end at the bottom, plant the tubers. They’ll continue to expand whether I do this or not, but this is my preferred method.
Put it in a sunny window and give it gentle watering. In about two weeks, you should notice growth. They grow rather rapidly, making them ideal for the impatient gardener because you may enjoy watching them develop.
See my post, “How to Plant Oxalis Bulbs,” for a comprehensive discussion of where and when to plant oxalis bulbs, as well as a complete guide on planting corms and dividing established plants (Corms).
Insect Pests & Typical Plant Diseases
A few common pests and illnesses can harm purple shamrocks. Mealybugs, aphids, and spider mites are just a few examples of pests. Indoor plants have a greater risk of pest infestation because outdoor bugs are generally blown or washed away by weather conditions. Use insecticidal soap to get rid of the pests. Powdery mildew, a fungal disease that causes white patches on the leaf, is a common ailment of purple shamrocks. Humidity and lack of ventilation are common causes of this. Don’t water your plants from above, and give them plenty of room.
Growing a Shamrock in Your Purple Pot
Little flowers with five petals grow in bunches atop a purple shamrock plant’s foliage, and they bloom from autumn through spring. The flowers, like the leaves, close up at night and during overcast days. To encourage further flowering, deadheading (the removal of spent blooms) is not required, but it will make for a neater plant. If you want your plant to bloom, you need to give it enough water, sunlight, and fertilizer. Deficiency-stricken plants may not bloom at all or only sparsely. But a shamrock that has been properly cared for will bloom reliably year after year.
Problems Often Encountered while Using Purple Shamrock
If you provide the right circumstances, purple shamrock plants are low-maintenance. However, environmental factors contribute to the prevalence of some disorders.
If there is a lack of either water or sunlight, the leaves will droop (or both). Temperature increases, however, may simply be the plant’s natural dormant phase. Try increasing the plant’s exposure to light if you suspect it is entering a dormant period when it should not. Don’t forget to keep the soil moist.
The leaves of your purple shamrock may be becoming brown or not appearing as vivid as normal as an indication that it is entering hibernation. Give your plant some space during this transitional period and reduce its water and food intake. Once you notice new growth, you can go back to your regular watering and feeding schedule. Any decaying foliage can be removed after that.