Purple shamrock is a perfect choice to accent an all-green indoor landscape. Its botanical name Oxalis triangularis would remind us of the triangle-shaped leaves that are trifoliate. Apart from its colorful foliage, this plant also produces small, white flowers making it more attractive.
One good thing about the purple shamrock plant is that it is very tough, one you couldn’t kill easily. So, there’s no need to be anxious about the care and maintenance because it will pretty survive on its own. Oxalis triangularis is very easy to tend whether in an indoor or outdoor setting.
- Scientific Name: Oxalis triangularis (formerly Oxalis regnellii)
- AKA: Purple shamrock, Shamrock Plant, False Shamrock
- Similar to: Clover or trefoil Plant
- Native to: Africa and South America
- Shape: Clover-shaped (trifloliate)
- Maximum Size: 50 cm (20 in) tall and broad
- Watering Requirements: Once every 2 weeks
- Light Requirements: Full to partial shade
- Preferred Humidity: Moderate
- Preferred Temperature: 15 to 27oC (59 to 81oF)
- Soil or Potting Medium: Well-drained, rich in humus
- Fertilizer: Fertilize every 2 to 3 weeks with 1/2 strength fertilizer (growing stage)
- Propagation Method: Division of tubers
- Toxicity: Non-toxic to pets and humans
- Vulnerable to: Mealybugs, Spidermites, rust and ring spot
Although it’s common name is purple shamrock, this plant is not a real shamrock. Thus, don’t be surprised if you ever hear other people call it a false shamrock. In all fairness, those clover-shaped leaves make it look like a real shamrock.
But technically speaking, Oxalis triangularis belongs to the wood sorrel family also known as Oxalidaceae. It contains oxalic acid which gives it a sour taste when ingested. The plant can grow to about 50 cm (20 in) tall and broad.
It is native to Africa and South America. The leaves of this plant exhibit nyctinastic movement wherein they tend to close during the night like a folded umbrella and opens during the morning when the sun is out.
This false shamrock can tolerate full sun to partial shade light conditions. In an indoor setting, Oxalis triangularis prefers to have bright, indirect light. An east-facing window is an ideal location as it provides the morning light that’s best for this plant.
Extreme low light conditions will lead the plant to grow thin and weak so it’s okay to bring your plant outside to give it a boost. While bright light keeps the purple leaves vibrant, direct exposure to intense sunlight can lead to leaf scorch. It’s important to keep the balance to avoid potential damages.
Plants have the tendency to lean towards the direction of light. To prevent uneven growth, turn your purple shamrock plant around from time to time. This will help even out the plant’s exposure to light.
Allow the soil of your false shamrock to dry in between waterings. To avoid overwatering, always check the moisture content of the soil by inserting your finger at least 2 inches below the surface. If it still feels moist, you may skip watering.
Once the soil is partly dry, water the soil thoroughly to prevent the plant from wilting. Make sure to drain any excess water from the pot. Good drainage is important to prevent the plant from acquiring root rot.
Oxalis triangularis will normally enter a period of dormancy. At this point, you have to stop watering the plant. Allow your purple shamrock to have that period of rest. Once new plants start growing, you may resume watering again but you have to do it lightly.
Humidity & Temperature Preferences
Your oxalis plant will need moderate humidity to thrive. When the environment indoor gets too dry, a little misting will help to keep your plant happy. It prefers to be in places where the temperature is cool, around 15 to 27oC (59 to 81oF).
A prolonged condition of high temperature (exceeds 27oC (81oF)) will cause stress to the Oxalis triangularis. You’ll observe that the leaves will droop making the plant look tired. The stressful environment will signal your purple shamrocks to go dormant prematurely.
Plant Food and Potting Media
For Oxalis triangularis, the soil must be well-draining and rich in humus. A mixture of one part potting soil, one part potting mix, one part peat is a good combination. Adding amendments such as perlite will help improve the drainage.
To sustain the plant with the nutrients that it needs, apply fertilizer during its growing season (Summer to Spring). Every 2 to 3 weeks, apply balanced houseplant fertilizer that is diluted to half of the original recommendation. The steady supply of nutrients will help the oxalis produce more flowers.
Make sure to refrain from fertilizing once the Oxalis triangularis enters the dormancy period.
Regularly prune the dead and aged leaves to keep the purple shamrock healthy. Carefully pinch down the brown leaves. Purple shamrocks that go dormant will naturally shed off their leaves. Wait until the whole plant turns brown, then cut the stems back down to its base.
Leave the pot in a cool and dark place for around 3 to 4 weeks to give it time to rest. After that, new growth will show and it’s time to resume watering and fertilizing the purple shamrock.
You can repot your Oxalis triangularis year by year every late Spring. But keep in mind that it would still depend on the growth habit of your purple shamrock. Some plants would need frequent repotting while others won’t.
Purple shamrock prefers to be a little pot bound. Here are the step by step procedures to properly repot the Oxalis triangularis:
- To ease repotting, water the pot ahead of time to loosen the soil. Let it sit for about hours or until the soil is partly moist.
- Carefully remove the purple shamrock from its container by tilting it sideways and tapping the pot. Once the root ball is out, remove the surrounding soil to expose the tubers.
- Remove any dead or unhealthy tubers.
- You have the option to divide the tubers for propagation. Or, you may pot the whole plant in a container that is one or two sizes larger than the previous one.
- Use a fresh potting mix to fill the gaps inside the pot.
- Water the pot until the soil is fully saturated. Drain the excess water so the plant won’t develop root rot.
- Place the oxalis in a partly shaded location.
Purple shamrock has a tuberous root system. Tubers are enlarged portions of the roots that serve as storage of nutrients for plants. Through these organs, the plant will be able to sustain perennial growth.
Propagating Oxalis triangularis is made easy with the presence of these tubers. All you need is to divide the tubers and plant them separately in pots. However, do the division only when the roots of the mother plant are already bound to avoid premature propagation.
Plant the tubers in well-draining potting soil and water it thoroughly. Place in a bright location and water only when the soil is getting dry. The tubers shall start showing new growth after 2 to 3 weeks. The best time to do repotting is during the Spring season.
Pests and Diseases
The common pests you’ll encounter with Oxalis triangularis are mealybugs and spider mites. Mealybugs will appear like a white cotton coating on the surface of the leaves. Spider mites create that weblike appearance on the underside of the colored foliage.
You can easily get rid of these pests by spraying them off with water or diluted horticultural oils and dishwashing liquid. You may also pinch off the damaged leaves if necessary.
Oxalis triangularis may also develop diseases such as rust and ring spots. Rust is caused by fungi while ring spot is due to a virus. To avoid the spread of disease, see to it that you remove the infected parts of the plant. For rust, you may apply sulfur copper powder.
It’s also possible to prevent the occurrence of diseases by maintaining the ideal growing condition for your plant. Stop watering the foliage of the plant to avoid inviting the growth of pathogens.
All members of the wood sorrel contain oxalic acid that gives them the sour taste characteristic. When ingested in very large quantities, it will become toxic to pets and humans. According to APSCA, the soluble oxalates present in the plant can lead to kidney failure, tremors, and salivation.
However, you need not overly worry because the toxicity will only manifest if your pets have eaten very large amounts of Oxalis triangularis. A one time experience of ingestion will not create such harm.
There’s no doubt that Oxalis triangularis successfully captured the hearts of many. Not only has it been a good outdoor ground cover, but it’s also perfect when placed in an indoor location. Growing this plant will surely be a rewarding journey.
The purple leaves will surely add color to a green landscape. The white flowers will even add more attraction to your home year-round.
Why is my Oxalis triangularis drooping?
A drooping behavior in Oxalis triangularis is often a sign of heat stress. If your oxalis is subjected to direct exposure to the sun, the strong intensities will induce stress in the plant. In the same manner, when the temperature rises for a prolonged period, the oxalis will suffer the same fate.
High levels of temperature will cause the transpiration rate to hasten thus, the purple shamrock will easily lose the moisture that it contains. Water plays a very important role in keeping the cells of the plant turgid. So, the lack of water leads the plant to lose its turgidity.
See to it that you immediately water the drooping oxalis. The plant will easily recover when it gets hydrated. It’s also best to keep the plant away from heat drafts and direct light sources.
Is Oxalis triangularis poisonous to humans?
Even though the leaves, flowers, and roots of Oxalis triangularis contain oxalic acid, those parts are surprisingly edible. Yup, you heard it right. They can be eaten either raw or cooked.
However, you should consume them in moderation and with great caution. Large amounts of oxalic acid can limit the supply of calcium in the human body. Make sure to properly wash the edible parts before you eat them.
Does Oxalis triangularis die in the winter?
No. Oxalis triangularis enter a period of dormancy during the winter. The foliage withers and die and you have to cut back the plant down to its base. However, the tubers below the soil surface remain potent so never throw them away.
After 4 to 6 weeks of dormancy or when the growing conditions get ideal, you will see new stems and leaves growing from the soil. Oxalis triangularis is a pretty hardy plant species so you need not worry over it when the winter comes.