Oxalis triangularis
The striking purple leaves stand out amongst green indoor plants and it’s also photophilic, which mean that the leaves open and close in response to light in a process called nystinasty. At night the leaves fold down and during the day they will open up. Have a look at some of these time-lapse videos.
Some plants are hard to take care of (I’m thinking of a Fiddle leaf fig) but the Oxalis Triangularis is fairly low maintenance.
Oxalis is a genus of the wood sorrel family and is well known for being an invasive weed in most gardens. However, there are some varieties of Oxalis that are perfectly well behaved and don’t spread all over the places, such as the Oxalis Triangularis. Oxalis is often referred to as a purple shamrock or false shamrock. It’s history can be traced back to St Patrick in Ireland, even though the plant originated in Brazil.
How to care for it:
Light: Keep your Oxalis Triangularis in a filtered bright to medium light but away from direct light. It grows well in morning light (i.e. East window). It is fairly hard to burn since Oxalis grows outdoors, the glass in your windows will filter out a lot of the intensity of the light, however it will grow best when it’s away from direct sunlight. Take a look at some of the images at the bottom of this article for the lighting suggestions.
Water: Allow the soil to dry between watering, ensure the top 2cm of soil is dry before watering. The worst thing you can do with bulbs is overwater as it will rot the bulb. Expect to water about once every 2 weeks.
Soil: A well-drained potting mix works well. Use a standard Premium indoor potting mix. Oxalis will NOT grow well in overly wet soil but does like moist soil. Make sure your pot has a drainage hole.
Pot: Oxalis pots need to be deep, shallow pots will not work well. Avoid growing them in a pot with other plants as they can go dormant and their growth requirements are different. As the Oxalis tends to grow and bend towards the light, you should also rotate your pot every 2 weeks to ensure the foliage grows evenly.
Temperature: Standard indoor temperatures are fine. The ideal temperature is around 60-70°F(15-21°C). Temperatures above 75°F/24°C become problematic. At high temperature, the Oxalis will start to look ‘tired’ and may go into dormancy and drop all it’s leaves.
Fertiliser: I don’t find fertiliser necessary in new plants, but you could add every 2 months if the soil is older than a year. Premium potting mixes usually contain slow release fertiliser for at least 4 months worth.
Some interesting facts
Pests and disease
Rust: One of the most common diseases is rust, which appears in the lower half of the leaves. I encountered this on one of my plants. You can use some rust sulfur copper powder to stop the spores from multiplying but there is no way to reverse the damage. Best is to cut off the affected leaves and wait for regrowth.
Ringspot: This is caused by the ringspot virus which is due to the presence of aphids, also known as plant lice.
Burnt leaves: Too much direct sun can burn your Oxalis, especially if you have moved it from a medium light location to a high light location too quickly. You will know if your leaves are burnt if they look dry and crispy on the edges. This is different to Rust which looks more like mold all over the leaves.
Characteristics: Oxalis came to the United States in the 1980s and it’s popularity continues to grow. Indoors. When the weather is warm and there is adequate moisture, the Oxalis blooms with small, pale bell like flowers. There are about 300 species of Oxalis, the green leaf variety that makes great indoor plants is the Oxalis Regnellii. Oxalis gets it’s name from the fact that it’s high in Oxalic acid due to it’s tangy taste.
Dormancy: Oxalis occasionally go dormant and this happens suddenly in summer (which is quite strange for plants as it’s the growing season), this usually happens every 2-7 years, it may look like your Oxalis has died. Don’t panic! Simply stop watering and let the soil dry and put it in a dark corner. In about 2-4 weeks you will see a new leaf emerge and then you can start to water again and move it back into a sunny spot. They can also go dormant when temperatures exceed 80°F/27°C
Toxicity: Oxalis is classified as an edible plant, however it’s very bitter for humans. Oxalis is poisonous to pets if eaten. Watch out for kitties that chew on the leaves.
Examples of Oxalis in good lighting positions
You should have everything that you need to grow your Oxalis. If you have any questions feel free to ask a question below.
Check out Oxalis Triangularis part 2 >>
Happy Growing.
So much info I didn’t know my late father had oxalis in the kitchen and I have a cutting from that plant to remember my Dad so it’s great to know more about caring for it
Yes, Oxalis are known to live for a long time and passed down from generations to generation and are referred to as ‘heirloom plants’. They are fun to grown because how often do you see purple leaves!
Thank you so much for adding in the rust spots! Any other site I’ve looked at has NOT mentioned that. I appreciate it!
Yea I had rust on my oxalis which is how I know about it. Cutting off the leaves wasn’t as bad as I thought, they grow back pretty quickly.
do you cut just the leaves or the stems too?
You can cut the stems all the way back to the bulb. If you cut the leaves the stems will die anyway and will fall off in a few days.
Thanks for the info on the rust. I’ve had my oxalis for a year now. They were beautiful and 4 months ago it just completely died. And had rusts on them. I wasn’t sure what to do so repotted it to see if there was any bulbs. We are just in the first 2 weeks of spring here and it’s starting to grow beautiful again but noticed that the leaves have the signs of rusts. If I cut all the stem off nad only the bulb will it grow again?
Yes it should grow back, the bulb should be rooted and as long is it has water and light it should regerminate. I would try and locate why is getting rust again, make sure its not to crowded with the other plants, the rust spores are usually from another infected plant. You could also use a rust powder to stop the spread. The anti rust powder(sulpher) will kill the current rust spores (although the current oxalis leave will be permanently damaged by the rust and only new leave will grow nicely)
Hi! I’m new to the oxalis world and found your article very helpful.
I’d like your help with a few questions.
My plant is very recent, only three stems with leaves (for now) and a flower stem. One of the stems, the newest one, has one leave smaller and under developed. The two other ones are already big and have their full colour. Is this normal/ commun?Have I done something wrong?
I’ve also seen a few flying bugs, similar to fruit flies, coming out of the soil. What can I do about this?
Thank you
Hi usually the new stems will grow pretty quickly to the size of the existing ones (ie within a few weeks). The fact that you have fungal gnats (what look like fruit flies) is a problem. They come because the top of your soil has been too damp for too long and the gnat larvae have bred. The best things to do is get those Yellow sticky fly papers to catch the existing gnats. Ensure you don’t keep your soil too damp, only water when top of the soil has been dry for 2 days. The gnats are generally harmless… Read more »
Well mine is ok but is it normal that I need to pick at the plant every couple of days, because some stems become limp and sort of wet, soggy, I just pull it out but just wondering if anyone else has had that happen to their oxalis?
This happens with mine as well, its usually due to inconsistent watering or letting the oxalis dry out. If the Oxalis is correctly watered the stems won’t die and shrivel up ever few days. Just keep it watered and you will get more stems and thicker growth.
Great, thanks. I think I will get this one the plantmaid
I’ve accidentally left mine out in the pouring rain and I think I’ve drowned it. Leaves are wilting, and I can’t repot or anything until I get the chance to after midterm season. What should I do to revive it?
Oxalis is a bulb so they don’t like sitting in water, it will eventually rot the bulb. To dry out the soil, leaving it on the window shelf in full sun is probably the easiest option. Oxalis would rather be dry then flooded with water. If you don’t think the soil will dry out within 4 days then I would repot it. I’m assuming your pot has a drainage hole at the bottom, so it should dry out fairly quickly if you keep it away from the rain and water.
Is oxalis are behave same as through out all seasons..? What care should we take in summers
It’s very similar throughout Summer and Winter, they grow faster in spring and summer and enjoy full sun.
Do the leaves looked burnt when they’re in a space that is too hot but indoors? Mine was so beautiful when I bought it and now it doesn’t look well. I don’t want to give up!
They can get a shock if you suddenly move them from mild light to bright light, the old leaves might burn but new leaves should be ok. Oxalis is a bulb so if you haven’t over watered it (otherwise it can rot), it will usually recover. Let it dry out and water again when the top 2cm of the soil is dry. You might have to wait for new leave to grow in the bright light spot. If its to close to an East or West facing window, you might want to move it 1-2m away from the window.
How many bulbs should be planted in the same small indoor pot?
Hi Donna
I have only planted one bulb in my pot, but in theory you can have more than one bulb, the recommendation is to plan them 3 inches apart.
Regards
Hi Donna, I planted 5 in my 12cm pot and it looks great. The bulbs were very small though. They were half cm by 2cm.
I find that if I don’t water every other day, leaves start to wilt and die. I’ve never known a plant drink so much.. And if well watered it produces small pink flowers. Very odd! Maybe I have an exceptional plant??
The type of soil is a big component to determine how much you need to water, if you have a loose coarse potting mix that doesn’t retain water than you will need to water more often. Every other day seems like a lot for oxalis, you could get some new organic potting mix from the nursery and it will retain water for a lot longer. But hey if you are getting it to flower then it’s happy.
Can I mix the purple oxalis in the same pot with the standard green oxalis?
Hi Michele, yes you can plant regnellii and triangularis in the same pot. The question is How far apart should oxalis bulbs be planted? – you should space them about 10cm apart. Good luck.
will they bulb grow if I dipped the hole too deep?
Generally, a depth of 2-4cm will work best.
Great article! I have recently purchase an Oxalis & I’ve noticed that some of the leaves are curling slightly at the edges. I’m still trying to find the best spot for it, but do you think it’s getting too much light? I have it couple of metres away from a South east window.
Thanks 🙂
Oxalis do well in bright to medium light, a south window (in the northern hemisphere) will get a lot of light the whole day and usually placing your plant withing 0-2 meters would work well but it might be too bright. As long as it isn’t getting to much direct sun as the leaves could burn.
Is it ok if my Oxalis is in a pot with no drainage?
Yes, the only reason people say you should have a pot with a drainage hole is that because people over water, and the water then builds up at the bottom of the pot and causes root rot. If you know what you are doing and don’t over water then you don’t need a drainage hole. 🙂
When I first bought my oxalis there were lots of aphids crawling around, which I have now managed to get rid of. The oxalis now looks healthy however I’ve noticed that new leaves that sprout are very pink (almost fuchsia) in tone and then wither within a day or two of sprouting. I’m making sure that I don’t over-water and rotating the pot regularly but I’m not sure what’s going wrong. Please could you give me some advice as to why this may be happening? Thanks in advance 🙂
Hi Kay, I have never seen my sprouts wither after a day or two, they usually shoot up a about 0.5cm a day (and I don’t water for a week once I see them growing because I know they have enough moisture for a while). I’ve had fungal nats on Oxalis but not aphids which I know eat young shoots, i’d make sure they are definitely all dead (use some of the home remedies out there, garlic/pepper mix, or Neem oil works for everything 🙂 Don’t worry about rotating the oxalis until the stems are longer than 5cm. Good luck.
Can the leaves last all year indoor? I live in Los Angeles. Thanks!
Yes oxalis leaves last all year round. The leaves are different from the flowers which only bloom occasionally.
What are the main signs that your oxalis is desperate for water or that it’s being watered too much?
Hi Carlos, with too little watering the stems will flop, shriven, and die – you will notice a bunch fof the stems starting to shrivel and easily detach directly from the bulb. Overwatering is a bit more serious as the bulb will rot, you usually see darker black and mushy stems – repot immediately and give adequate drainage…you might be able to save it.
Good luck
Do we need to lure oxalis iron cross bulbs before planting them ? I have planted some bulbs in different types of soils, almost a month but not sprout at all. The types of soils I use :
1. good mix soil and compost
2. I also try : mix of pumice, perlite, vermiculite, peat moss and soil
Oxalis ‘Iron Cross’ is just another member of the oxalis family. It should grow fine in a good potting mix and one good full watering, after planting the bulbs give it one full watering until the water drains through the pot, then leave it for a week or two in medium sun, if it’s not sprouting its probably not the soil that is the issue.
Hi my Oxalis is outdoors since May and has doubled in size mountains of leaves and lovely pink flowers, but within the last few days it has red powdery/dusty spots on the underside of the all the leaves and there is a red tinge on the soil underneath. what is it and can I treat it? many many thanks
Hello, I got a big oxalis as a present, but my house doesn’t have enough sunlight. It has a north window and I don’t think it’s enough light for it. I put it in the balcony but then all the flowers died and the stems wouldn’t stand straight. The leaves would still open and close but they weren’t straight. I stopped watering it, I thought maybe it’s because I over watered it but now the leaves are closed and the plant shows that it needs water. I don’t know if this is going through dormancy and I should leave it… Read more »
Hello fellow plant lovers, I was wondering if I can get some advice on my Oxalis Triangular (Green). I’ve had it for maybe like 2 years and it’s been through a bunch of stages. Sometimes it looks healthy and full and other times a lot of the leaves are turning yellow or losing their normal green color. They also more recent have a reddish/pinkish underside. More visible now that the green is fading. The last week I feel as though the leaves are opening during days as they normally do in the light. I know they would close in the… Read more »
Sounds like it could be multiple problems, if the stems are very long its usually because there is not enough light and the plant is trying to grow towards more light. If the stems are not straight I’ve found this is usually a problem with the soil quality, or you have some pests in the soil. Since you have a lot of concurrent issues I would repot in new soil, cut off the stems showing rust marks, try place the oxalis in an east-facing window so sort out the light issues. Hope it comes right.
Hi, I bought an oxalis for the first time. And I think I have a perfect spot at my place after this article. It’s in plastic pot and I want to put the plant in a ceramic pot and in a new soil mixture. How should I do it ?
Yea I think its fine, just make sure the ceramic pot has a drainage hole and saucer. Also use a good quality indoor potting mix for the soil. Happy growing!
Thank you for sharing so much information!! I have an oxalis that I had on a table about 2 meters away from a window facing east. I noticed that any new leaves would die and not get to full size. I have moved them closer to the window (about 30cm away from the window) and I noticed that some of the big ones are not fully green and it looks almost dead and a new leaf also dead. What could be causing this? (I know my place is a bit hot, around 25 degrees inside) Also, my mom has the… Read more »
Hi Lorena, It sounds like you have got the Oxalis in a good position and facing East works well. Oxalis will do ok in 25 degrees. My guess is that the soil or watering is the problem, new leaves turning dead is often a sign of damaged roots or soil (or pests in the soil). I would re-pot your oxalis in some high quality indoor potting mix (clean off all of the old soil of the bulb under a running tap). Water only when the top 2cm of the soil is dry. As for the food, a new potting mix… Read more »
Hi! I just found this little guy in one of my fern pots. Yesterday, I decided to transfer him into his own pot. What are the chances of this growing and multiplying?
Hi Rica, I think there is a good chance you could get some more sprouts from the main bulb, just keep it watered and in a good light position and you should see some growth within 2 weeks. Good luck.
Great! Something to look forward to! ☺️ Thanks!
I have Purple Shamrock and I noticed that the bottom of it’s stem is getting rotten by a white colored fungi, and I don’t have any idea how to treat it. I removed the affected stalks but I think all other stems were already infected. That certain pot actually died.
Hiya. I recently bought the purple version and planted three sets together in a pot. It stays indoors in a corner of a SE facing window. They initially grew quite rapidly in 2.5 weeks and were bushy as well. I’d turn the pot often as I noticed they were directing towards the light. But now they’ve all grown over the sides of the pot 🙁 and some stems are curled. Is this normal behaviour? Do I trim them all back near to soil line and place in an area of better light? Thanks. P.s. your post and ensuing commentary has… Read more »
Hi Ana, yes looks like your Oxalis has taken a turn for the worst. The curled stems are usually a sign of root/soil issues rather than light. Hopefully, that pot has a drainage hole otherwise the roots might be getting root rot. The SE window should be ok as the leaves don’t look burnt.
I have north facing balcony with open space ..can I plant them?
Hi Sahifa, it depends on which hemisphere you are in. If you are in the northern hemisphere then north facing will be fine. But in the Southern hemisphere, the north window is too bright for Oxalis.
Hi! I’ve had a oxalis for about 18 months now. It has a lot of the purple leaves, but is rather “leggy.” I’ve never been able to get it to flower. Is this because It isn’t getting enough light? Or, what do you think I should try?
Hi Jenna, Yes leggy stems is due to the wrong light position, the leaves are trying to reach for a better sun position. I’ve found this occurring when I’ve had my oxalis next to a window that very strong sun but for a few hours a day. As for the blooming, it will only bloom in spring and summer. I noticed my oxalis started blooming when I repotted it into fresh soil, maybe it was the extra nutrients.
I have north facing balcony but I receive indirect sunlight .. can I grow these?
My oxalic has yellow spotsnunder their leaves.
How can I get rid of them?
Hi Augie, This is rust disease, there is no way to reverse it. You can stop the spores from multiplying by using a copper dust treatment. However, the best way is to cut off the affected leaves before it infects the other leaves. Also check what other plants your oxalis is around, rust often is spread from other plants.
The corms of my shamrock are above ground, is this a problem?
Hi Keith,
No this is fine, I’ve tried to grow oxalis with corms exposed to the surface and with them buried, both grew fine. Ideally, they should be about 1 inch deep to get a good root system. However, even when they are growing the corms have been known to grow up and be partially exposed to the surface.
Hi Augie
This is definately Rust, check out the following page: https://www.rhs.org.uk/advice/profile?pid=756
The only thing you can do is remove those leaves before is spreads to the other leaves.
Happy growing
I’ve had one of these plants for a few years now, and it’s always done incredibly well. It’s never entered a dormant period, and it’s rarely not flowering. I moved house 8months ago, and settled it into its new home getting direct afternoon sun and the leaves no longer open and close and have turned green. I assume it’s not happy with the light levels, but the article says it’s happy in direct sun, and I’ve seen it thriving in hot countries :/ I ran a google search for leaves turning green, and could only find reference to yellow leaves… Read more »
Hi! How do you know when your oxalis needs watering does it give you any signs like other plants? Thanks- newbie oxalis parent
Hi, Oxalis will start to droop when it doesn’t have enough water, however I’ve found by that time the damage is done, a lot of the stems won’t recover if you re-water. The best is it just give oxalis consistent watering, check the top 1cm of soil and only water if it’s dry (roughly every 3 days in my experience…but it depends on season and how hot it is).