Since I have so many houseplants, I resisted getting any new ones for a while even though I've always admired Oxalis triangularis, or the Purple Shamrock Plant. One day I was shopping for my summer annual plants at a nursery, and they had a display of these plants and I told myself that I would just grow them as annuals.
Who am I kidding? These plants flourished in a pot outdoors, but then I firmly decided to bring it back indoors to enjoy as a houseplant! Do you want to know how to grow Oxalis triangularis indoors, or even outdoors? Keep reading and I will fill you in on all the details!
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Table of Contents
Oxalis Triangularis Care
Before I get into the care of potted Oxalis triangularis, here is some interesting information that would be good to know. (If you don't care you can move onto the next section but I promise this is interesting information!)
You'll sometimes see this plant called False Shamrock Plant. Why is it a "false" shamrock? If you are familiar with clover, you'll know that the leaves strongly resemble clover which is in the Trifolium genus. "False Shamrock" plant actually belongs to the Oxalis genus.
Oxalis triangularis belongs to the Oxalidaceae family, or the wood sorrel family.
This plant's foliage consists of trifoliate leaves (compound leaf with 3 leaflets). Depending on the variety you have, the triangular leaves can be the plain green type, or they also come with dark purple leaves like my own plant.
Depending on the type you have, the small trumpet shaped five-petaled flowers come in different colors. My own plant has lavender or purple flowers, but there are other types that have white flowers and even yellow flowers.
These plants are native to a few countries in South America, including Brazil, but did you know that Oxalis triangularis is actually hardy in zones 6-11?
If you live in these zones, Oxalis triangularis makes for a lovely perennial plant that will keep spreading and add plenty of interest to your garden.
I've never tried growing these as a perennial, but know that it can be possible depending on where you live! If you live in a marginally hardy zone for this plant, be sure not to miss my Pushing Your Hardiness Zone blog post to ensure your chances of success!
One intriguing part of this plant is its ability to close its leaves (and flowers) at night and open them back up during the day, making it the subject of some wonderful time-lapse videos.
This phenomenon is called photonasty behavior. Funny word right? Check out the cool video on Wikipedia where you can see the Oxalis triangularis photonasty behavior. (I chuckle every time I see the word photonasty).
Oxalis triangularis actually grow from tubers and these plants do have a dormancy period, so if you think your plant is suddenly dying, you are probably OK and I describe what to do later in this post.
Lastly, the leaves are edible, so you can sprinkle some of the beautiful leaves as garnish if you'd like...but don't eat too much because they contain a lot of oxalic acid.
Oxalic means sour, and it is sour because of the high oxalic acid content. A little won't hurt you at all, but too much will deter your body from absorbing calcium.
Just don't go eating full salads of these plants. A little garnish will do no harm though 🙂
These plants are incredibly long lived and there have been reports of families having these plants for over 100 years. Talk about heirloom houseplants!
HOW DO YOU CARE FOR AN OXALIS PLANT INDOORS?
Let me go through some basic care information and growing conditions, and I will later describe how to plant the corms if you chose to purchase corms instead.
LIGHT
Light levels for this plant is a very important topic to consider indoors.
Indoors, you'll want to give these plants some direct sunlight. Depending on where you live and how strong the sun and light is, you may want to give this plant at least half a day's sun.
Is your Oxalis triangularis leggy or sparse? If it is, chances are that it is not receiving enough light.
I find that only indirect light indoors is not sufficient in many cases. Your plant will still grow, but not as full.
Move your plant to a sunnier location, with at least partial sun if you can, and it will respond by producing lusher growth and turn into a fuller plant. You should have this plant right in front of a window for best results.
These plants can even take full sun indoors, as long as you can keep up with watering because it will dry out much more quickly with bright light.
A few words about taking your plant outdoors. Although these plant do like some direct sunlight, please be careful when you place any of your houseplant outdoors. You can NOT move a plant that has been indoors immediately outdoors into direct sun.
If you do this, your plants will burn. Even the ones that like a lot of sun. To make the transition from indoors to outdoors safely, you'll need to make sure to harden your plants off.
This means that you will gradually acclimate your plants to brighter outdoor conditions so that the leaves don't burn. If you'd like to know more information on how to do this, please read my blog post on how to harden off indoor plants and place them outdoors safely.
You will be glad you read this. I'd had so many people tell me that taking plants outdoors is really bad because they burn and die. This is because those plants were not hardened off.
So be sure to not skip this step and read that blog post I referenced above!
WATERING
This plant likes slightly moist conditions, but do allow the top inch of soil or two (2.5-5cm), depending on the size of your pot, to dry out before watering again.
When you do water, make sure you give your Oxalis triangularis plant a good soak and allow excess water to escape the drainage hole.
Good drainage is very important so always use pots with drainage holes! Having no drainage holes is an invitation for root rot and we don't want that.
Avoid letting these go totally dry especially for long period of time or you may induce a dormancy period. The dormancy period will occur anyway, but more about that later.
Avoid keeping these constantly wet indoors though may cause the corms to rot, and then you can say bye bye to your Oxalis.
FERTILIZING
During active growth, I like to fertilize dilutely with every watering. My favorite fertilize that I've switched to for pretty much all my houseplants is Dyna-Gro Grow (link to Amazon).
I add ¼ teaspoon of Dyna-Gro Grow per gallon of water and use it just about every time I water all my plants.
I love using it because it is urea-free and it contains ALL of the macro and micro nutrients that plants need. If you pick only one fertilizer to use for your indoor plants, you can use this one for all of them and with great results! I've been so happy with the results I've been able to achieve with this fertilizer.
TEMPERATURE
These plants do prefer temperatures on the cooler end. An ideal temperature range for oxalis plants is 60-75F (16-24C).
Consistent temperatures of over 80F (27C) can cause the plant to shut down and start to go dormant.
I like to bring my plant outdoors in the Spring once temperatures are warm enough. I keep my plant outside until about October or even November. At that point, I place it in a cool, dark place and stop watering. This will force it into dormancy.
Over the next few weeks, it will go into dormancy and all the leaves will dry up. Keep an eye on it because it may start to come into growth again after a few weeks. If you notice it start to grow again, immediately place it in front of a window so it can resume growing.
Here is my plant after it started growing back after dormancy:
If you don't notice any growth yet after about 4-6 weeks or so, don't worry. Clean up the dead leaves, place it in front of a bright window, and starting watering and watch for signs of new growth.
With good conditions indoors, new leaves will start growing remarkably fast.
SOIL
For this plant, I like to use 3 parts of an all-purpose potting mix and 1 part perlite. This is my standard mix that I like to use for many plants.
Why is My Oxalis Dying?
If your Oxalis triangularis starts to look a little rough, despite nothing changing in its care, it may simply be entering its dormancy period on its own.
It is not dying, so you should not worry! Think of it as a chance to rejuvenate your plant. The dormancy period is normal so you'll just have to get used to it.
Sometime after the main growing season each year, your Oxalis may start to look a little droopy. The leaves may stop opening up during the daytime.
At this point, it is time to give your triangularis a rest. I would recommend to stop watering at this point and let the leaves completely dry up. Then cut the leaves off and place it in a cool, dark location (above freezing) and let it rest for 3-4 weeks, or even up to 6 weeks. Do not water during this time period.
At the end of the dormancy period, bring your plant out of hibernation and back to a sunny indoor window, and start watering lightly. When you see signs of growth, you can water a bit more. Until you see new growth though, don't add too much water.
Keep it on the drier side until growth starts to pick up, but don't ignore watering.
Or if you'd like to make more plants, this is also a good time to divide the tubers and make as many new pots as you'd like. After the dormancy period, you can divide your tubers to your liking.
Or if you'd just like a specimen plant, keep things as is, or maybe pot it up to the next larger pot size.
PESTS & DISEASES
Pests and diseases are always a nuisance. The beautiful part about your Oxalis triangularis plant is that if your plant is infested with any bugs or diseases, if you don't want to treat your plant, you can always let it go dormant and start growing fresh foliage from scratch!
Otherwise, read below on some tips to treat your plant.
SPIDER MITES
Spider mites are a nuisance and like any pests, are best dealt with before the problem gets out of control.
Spider mites themselves are very small, but you'll be able to see very fine webbing on the foliage and they often hide underneath the foliage as well.
Mealybugs are another annoying pest. They will appear as white, cottony masses (and they contrast nicely against the rich purple leaves!)
I like to use an insecticidal soap to treat mealy bugs. Check out my post on treating mealybugs in order to have the best success at eradicating these annoying pests.
POWDERY MILDEW
Powdery mildew is a fungal disease that appears as hazy white areas on your leaves. It typically forms on dry foliage when your light conditions are low and it is very humid and temperatures are on the cool end.
Poor air circulation can also aggravate the issue.
Use an organic fungicide to treat your plant. Some people also have success with mixing a tablespoon of baking soda and ½ teaspoon of dish soap to one gallon of water and spraying on the plant.
THRIPS
Thrips are an exceedingly irritating pest to deal with. Fortunately, it is easier to manage thrips with Oxalis triangularis compared to other plants.
Why? Because you can let it go dormant, like I outlined in the previous section. You're essentially able to set the reset button very easily.
One of my Oxalis triangularis that got thrips outdoors. Note the multiple injuries on the leaf.
You can attempt to spray with insecticidal soap, but it will be pretty difficult to completely cover the plant. My plants are a tangled mess of foliage.
And unless you're able to effectively spray the entire plant, it's almost not worth doing.
Instead, I recommend following this procedure to eradicate thrips in your Oxalis:
Isolate your plant and allow it to go dormant by withholding water and allowing all the foliage to die off, as previously described above.
Once the foliage has all dried up, discard the dead foliage.
If you don't obtain an actual plant, you can simply order corms and pot them up to grow your own plants. It is very simple, convenient, and easy to do!
I actually purchased my own plant in the annuals section of a nursery, so I started out with a plant in a 4 inch pot:
Simply pot up your tubers about 1 to 1 ½ inches (2.5 to 4cm) apart and also 1 to 1 ½ inches deep. Don't space your tubers too far apart otherwise you won't have a full plant.
Plant the tubers vertically with the narrower end at the bottom. They will still grow regardless, but this is what I prefer doing.
Water lightly and place in a sunny window. You should have new growth within about 2 weeks or so. These are great plants for the impatient gardener because they do grow pretty quickly and it is fun to watch the progress!
For a very detailed post on how to plant corms, and also how to divide an existing plant, step-by-step with photos, check out my blog post: How to Plant Oxalis Bulbs (Corms).
OXALIS TOXICITY
Oxalis is toxic to cats and dogs because of calcium oxalate according to the ASPCA.
That's about it folks! I hope you've enjoyed this blog post and that you've taken some useful tips. Do you have any Oxalis triangularis? Comment below! I love to hear from my readers.
Thanks for your help. I bought some oxalis corms and did not know which end was up. Now I know the small end goes down. I figured it would not make much difference. I left my first oxalis in the perennial garden to overwinter and they survived here in southern New York. Have a good year.
A very informative site, Thank you 🙂
I am super excited to get mine going!!
I am messaging actually to let you know that because the plant is high in Calcium Oxalates, people with Medullary Sponge Kidney Disease should not consume the leaves even though they are edible in small amounts. I have this disease and stay away from foods with Calcium Oxalates!
Thank you again for your Wonderful site, I have learned so much 🙂
Thanks for the information, I've been thinking of getting one of these plants for a while. With this advice i have now ordered a few small plants. No doubt I'll be reverting back to this blog at some points.
Wish me luck .Regards. Keith.
How do you grow from bulbs outdoors in sunny South Florida? When would they go dormant? Thanks. Also if you plant them in the ground do you have to do anything special or will they also go dormant?
My indoor oxalis has become ridiculously sparse with only 13 leaves currently! Has it gone into dormancy and what should I do to help it? Also, it was given to me in a small pot with no drainage, should I re-pot it?
@Raffaele,
Hi Raffaele! I didn’t think my message had got through! It’s on a NW facing windowsill which gets light but not really any sun. It was given to me last September. My friend grew it from one she already had. It actually recently has grown four tiny leaf shoots and two flower shoots which is promising!
Yes it went through. I just have to approve people's first comments :-). I just saw in your original note that it's in a pot with no drainage. You will want to plant it in a pot with drainage for sure. Good sign that it is growing now! If you have a location that has some direct sun, you can move it there as this will be beneficial. Good luck!
@Raffaele,
Thanks Raffaele! Any tips for repotting it? Will it cope ok? Don’t actually know how I’ll get it out!
Thank you for answering my questions! I just realized that I was ignoring some basics....
Amazing site!
Hiya, I re potted my oxalis recently and the stems have drooped. The leaves are fine and healthy. But they won't stand straight and sort of droop to the sides of the pot. I have them on the window with lots of sunlight and they were fine. Any advice? Reading your blog I didn't even know they had a dormancy period. New shoots are emerging and it's flowering a little. Thanks!
Hi Matilda! It's normal for some of them to lean over so I wouldn't worry much about that! As the plant grows and fills out, it will look better. Does this help?
So grateful for you post! My plant went Forman and is now coming back after about 2 months. The stems and heads look good for a few weeks then just slump and die. Even the flower buds come up for a few days then shrivel and gone in a day. I did change the pot a few days ago, it was too moist in a closed up plastic small pot. Any other problems I could try to remedy. Thank you
You're welcome! Not knowing your growing conditions, I would just be sure to follow what I describe in the post and make sure it has good light, a freely draining potting mix, etc. Are you doing anything differently than what I placed in the post?
Hello! I have a a 6" pot from last year, I believe needs better soil, the soil I bought it in is rather hard, dry and compact. I would like to repot the corms into something new and fresh, what soil type do they like, and should I wait until Spring perhaps? Thanks! Todd from Memphis tn.
Hi Todd! You can use any good potting mix and add some perlite. For most of my plants, I like to use 3-4 parts of miracle gro potting mix, or Espoma potting mix, and 1 part perlite. These plants are easiest to divide when they are dormant. I would give it a good watering and wait until the next day to divide the corms. This will make the job a lot easier. Hope this helps!
I’ve got a plain purple shamrock that’s looking nice and healthy. It’s only got 8 stems, so I believe there’s only one corn in the soil. I’m hoping to be able to propagate it and make it bushier next year 🙂
I have a few questions pls:
1) Even though my plant looks healthy, it has not flowered. What could be the reasons?
2) How do you go about splitting the corms? Do you just snap it into several pieces with your fingers or do you do it quite precisely with a clean, sharp knife? How do you know where to separate it?
As far as the flowering goes, it may not have enough light. That's usually the reason in general for why plants don't flower. As far as splitting the corms, you can just separate them with your hands, or whatever you find easiest!
Thank you for the tips on this plant! I’ve really grown to love it and now have several different varieties. I didn’t realize these should be put away to rest. Mine each looked like they were going into dormancy about a month ago. I chopped off the dying leaves then new healthy looking leaves popped out immediately so I never ended up giving any of them time to rest. Is it too late? Should I chop off the new good leaves to force the dormancy. Thank you!! ??
Hi Meagan! If it's looking good now, I would leave it. Keep it in mind for next year though, especially if you've noticed that it was starting to decline and look a little ratty. I induce dormancy in the Fall every year and let it rest for a few weeks, and then bring it back into the light and it flushes out in beautiful new growth!
Hello! Do you know if its possible to force this plant to go into dormancy? I'm moving soon and I figure it'll be an easier transition to make if the plant is dormant!
Hey, I enjoyed reading the beginner's guide of growing oxalis ???? its' really helpful indeed! And i wanted to know more about this plant...Recently my oxalis got some yellowish kind of powder and it isn't looking healthy... Is it some kind of disease? If so, how can I get rid of it?
Thank You~
Thanks for your help. I bought some oxalis corms and did not know which end was up. Now I know the small end goes down. I figured it would not make much difference. I left my first oxalis in the perennial garden to overwinter and they survived here in southern New York. Have a good year.
Glad you found it helpful! You can also lay them on the side if you're not sure. They will grow 🙂
Hi thank you, the info is very helpful. My purple Shamrock is going to be very happy from here on out.
I'm glad you enjoyed the post 🙂
A very informative site, Thank you 🙂
I am super excited to get mine going!!
I am messaging actually to let you know that because the plant is high in Calcium Oxalates, people with Medullary Sponge Kidney Disease should not consume the leaves even though they are edible in small amounts. I have this disease and stay away from foods with Calcium Oxalates!
Thank you again for your Wonderful site, I have learned so much 🙂
Hi Faye! I'm so happy that you enjoy my site! Thank you for the tip, and I'm sure it will be helpful for others too 🙂
Thanks for the information, I've been thinking of getting one of these plants for a while. With this advice i have now ordered a few small plants. No doubt I'll be reverting back to this blog at some points.
Wish me luck .Regards. Keith.
You're very welcome Keith! Good luck with your plants!
How do you grow from bulbs outdoors in sunny South Florida? When would they go dormant? Thanks. Also if you plant them in the ground do you have to do anything special or will they also go dormant?
My indoor oxalis has become ridiculously sparse with only 13 leaves currently! Has it gone into dormancy and what should I do to help it? Also, it was given to me in a small pot with no drainage, should I re-pot it?
Hi Jill! What kind of light are you giving it? What exposure is your window and how far away from the window is it? How long have you owned it?
@Raffaele,
Hi Raffaele! I didn’t think my message had got through! It’s on a NW facing windowsill which gets light but not really any sun. It was given to me last September. My friend grew it from one she already had. It actually recently has grown four tiny leaf shoots and two flower shoots which is promising!
Yes it went through. I just have to approve people's first comments :-). I just saw in your original note that it's in a pot with no drainage. You will want to plant it in a pot with drainage for sure. Good sign that it is growing now! If you have a location that has some direct sun, you can move it there as this will be beneficial. Good luck!
@Raffaele,
Thanks Raffaele! Any tips for repotting it? Will it cope ok? Don’t actually know how I’ll get it out!
Thank you for answering my questions! I just realized that I was ignoring some basics....
Amazing site!
You're very welcome Vania! I'm glad you are enjoying my site! 🙂
Hiya, I re potted my oxalis recently and the stems have drooped. The leaves are fine and healthy. But they won't stand straight and sort of droop to the sides of the pot. I have them on the window with lots of sunlight and they were fine. Any advice? Reading your blog I didn't even know they had a dormancy period. New shoots are emerging and it's flowering a little. Thanks!
Hi Matilda! It's normal for some of them to lean over so I wouldn't worry much about that! As the plant grows and fills out, it will look better. Does this help?
So grateful for you post! My plant went Forman and is now coming back after about 2 months. The stems and heads look good for a few weeks then just slump and die. Even the flower buds come up for a few days then shrivel and gone in a day. I did change the pot a few days ago, it was too moist in a closed up plastic small pot. Any other problems I could try to remedy. Thank you
You're welcome! Not knowing your growing conditions, I would just be sure to follow what I describe in the post and make sure it has good light, a freely draining potting mix, etc. Are you doing anything differently than what I placed in the post?
Hello! I have a a 6" pot from last year, I believe needs better soil, the soil I bought it in is rather hard, dry and compact. I would like to repot the corms into something new and fresh, what soil type do they like, and should I wait until Spring perhaps? Thanks! Todd from Memphis tn.
Hi Todd! You can use any good potting mix and add some perlite. For most of my plants, I like to use 3-4 parts of miracle gro potting mix, or Espoma potting mix, and 1 part perlite. These plants are easiest to divide when they are dormant. I would give it a good watering and wait until the next day to divide the corms. This will make the job a lot easier. Hope this helps!
Hi there,
I’ve got a plain purple shamrock that’s looking nice and healthy. It’s only got 8 stems, so I believe there’s only one corn in the soil. I’m hoping to be able to propagate it and make it bushier next year 🙂
I have a few questions pls:
1) Even though my plant looks healthy, it has not flowered. What could be the reasons?
2) How do you go about splitting the corms? Do you just snap it into several pieces with your fingers or do you do it quite precisely with a clean, sharp knife? How do you know where to separate it?
Thank you 🙂
As far as the flowering goes, it may not have enough light. That's usually the reason in general for why plants don't flower. As far as splitting the corms, you can just separate them with your hands, or whatever you find easiest!
Thank you for the tips on this plant! I’ve really grown to love it and now have several different varieties. I didn’t realize these should be put away to rest. Mine each looked like they were going into dormancy about a month ago. I chopped off the dying leaves then new healthy looking leaves popped out immediately so I never ended up giving any of them time to rest. Is it too late? Should I chop off the new good leaves to force the dormancy. Thank you!! ??
Hi Meagan! If it's looking good now, I would leave it. Keep it in mind for next year though, especially if you've noticed that it was starting to decline and look a little ratty. I induce dormancy in the Fall every year and let it rest for a few weeks, and then bring it back into the light and it flushes out in beautiful new growth!
How big a pot should I use and how many corns for each pot
You can do a variety of size pots. Just space the corms out 1-2" or so until the pot is full.
What pot size should I grow these in?
It all depends on what you're starting out with. Do you have tubers or you already have a plant in a pot?
Hello! Do you know if its possible to force this plant to go into dormancy? I'm moving soon and I figure it'll be an easier transition to make if the plant is dormant!
Hey, I enjoyed reading the beginner's guide of growing oxalis ???? its' really helpful indeed! And i wanted to know more about this plant...Recently my oxalis got some yellowish kind of powder and it isn't looking healthy... Is it some kind of disease? If so, how can I get rid of it?
Thank You~
Hi Lemti. It's hard to say without seeing a photo. Can you please send the photos to my email and I can maybe help you out? theohiotropics@gmail.com