Shamrock is one of those plants that’s only popular during the St. Patty’s Day for a large portion of the population.
The rest of the year? Not so much. It’s kind of like winterberry holly or mistletoe.
But didn’t you know that you can grow it in your house and enjoy it all year long (other than the summertime?).
This guy will even bloom for you. And produce a variety of leaves that you can enjoy even during winter.
Plus, it’s a super low maintenance houseplant that not a lot of people considering growing. So if you want something unique, this is it.
Let’s talk about how to grow and care for shamrock!
Last update: 2/16/23.
Quick care guide: Shamrock (Oxalis spp.)
|Plant type||Perennial flowering|
|Scientific name||Oxalis triangularis
|Other names||Trifolium repens
|Soil type||Organic, rich, loose, loamy, sandy|
|Soil pH||4.5-6.5 (acidic)|
|Sunlight requirement||Partial sun in warmer zones, full sun in cooler zones (8-11)|
|Bloom season||Fall to Spring|
|Colors||Green, lime, white, purple, pink, lavender, white|
|Max height||12 inches|
|Max width||8 inches|
|Low temperature tolerance||50F|
|High temperature tolerance||80F|
|Ideal temperature range||60-70F|
|Humidity||Low to moderate humidity only (spray with water to raise humidity)|
|Watering requirements||Water when the top inch of soil is dry, more often for younger shamrock|
|Fertilizer requirements||Liquid, general purpose houseplant fertilizer biweekly during Fall to Spring|
|Plant food NPK||10-10-10|
|Days until germination||Usually not started by seed, but if so, takes up to 8 weeks to germinate.|
|Days until harvest||Non harvestable|
|Bloom time||Spring to Summer; foliage arrives 4 weeks after planting, flowers arrive 10 weeks after planting.|
|Speed of growth||Moderate|
|Hardiness zones||USDA hardiness zones 8-11|
|Plant depth||From seeds: 1.0 inches
From transplants: Same depth as original plant
|Plant spacing||2 inches between each Oxalis plant|
|Plant with||Japanese Painted Fern
|Don't plant with||Taller houseplants that block light or compete for nutrients|
|Propagation method||Transplants, plant division|
|Common pests||Thrips, whiteflies, vine weevils, blackflies, root bugs, mealybugs, spider mites, and worms|
|Common diseases||Ring spot, fungal rust, root rot|
|Grown in container||Yes|
|Care level||Minimal to none (easy)|
|Best uses||Indoor decoration, St. Patrick's Day, crafts, gifts.|
Oxalis spp., commonly known as shamrock, is natively from Africa and South America.
You may be accustomed to thinking it’s from kiss me Ireland, but it’s just a misconception. Shamrock is more than shamrock shakes or clovers in the field.
Now there ARE Ireland native varieties, but here in the US, we grow different Oxalis species.
You already know about it from decorating for St. Patty’s day. But they’re more than just a once-a-year plant.
These guys can be planted year-round for attractive, easy-to-care-for indoor pleasure. There are several varieties and they can be grown with just bright light.
This plant is a tiny house plant. Some species grow no more than 6-7 inches at most while others can topple 20 inches.
They can have a variety of delicate leaves that range in colors and shapes from lavender to white to green.
They also produce pretty blooms during the fall, winter, and spring. But not in the summer. They don’t like heat.
Shamrock will fold up their leaves at night and then open them again in the day when they sense light, so it’s one of those plants that “talk” to you.
Other names for shamrock include:
- Trifolium repens
- Dutch clover
- Summer plant
- Wood sprig
Where does shamrock come from?
The original Irish shamrock does come from Ireland. It’s a common lawn weed native to the country with its rhizomatous perennial leaves.
However, it’s been brought into other countries in different varieties.
In the US, you’ll commonly come across 3 different types that are differentiated mainly by their colors: purple, white, or green.
Shamrock is more than just that tiny green plant you pick from the field. The houseplant can be anything from variegated to striped. The leaves can be purple, green, or pink.
Even the leaf shape can be different sizes with varying patterns. The blooms are white or pink with delicate petals that peek out from the clusters of leaves. The shamrock leaves are three sided and has a symmetric shape overall, but can vary depending on the plant.
Is shamrock poisonous?
Shamrock is indeed poisonous. Pets, people, and any other creatures should be kept away from Oxalis plants. Ingestion may cause acid poisoning or oxalic acid poisoning.
Types of shamrock
There are many different types of Oxalis species, each with its own variations in color, size, and more. In the US, you’ll find three that are most commonly grown.
Green Shamrock (O. regnellii)
Green shamrock is one with bright green foliage. They can be various shapes from triangular to spade-shaped.
This is the most popular cultivar here with its large white flowers that contrast perfectly with the lush green foliage.
There are other variations that include variegated leaves, such as Irish Mist, Hairy Woodsorrel, Wood Sorrel.
Purple Shamrock (O. triangularis)
False shamrock has those dark, purple-colored leaves with lavender/white flowers.
The blossoms are light in color while the foliage is dark, so it’s very striking to look at.
Some purple types include Love Plant or Mijke. The leaves are purple, pink, or lavender. They’re symmetric with three sides. They’re lighter in the center with a rosy color.
Why grow it?
That’s a good question. A lot of people grow this plant because it requires little maintenance, is drought tolerant, and can withstand desert temperatures down to 10F before it starts to wilt.
It can be purchased from the nursery and then replanted in the garden with ease when it’s still manageable. It also doesn’t need any work nearly all season other than occasional watering or pruning.
Plus, it looks awesome. This plant can attract beneficial pollinators to your yard, such as bees and hummingbirds.
Is it beginner friendly?
Yes, shamrock is very easy to grow and good for beginners. Once you get it set up and rooted, it takes care of itself.
You only need to water it and prune it. Plus give it some plant food once in a while. But that’s about it.
Can you eat shamrock root?
Shamrock root from SOME species is considered edible.
They’re large and have been cultivated as a crop in New Zealand, however, you should avoid eating the roots without consulting a professional.
If you don’t know how to identify the root properly, you can cause adverse effects from ingestion.
How to propagate shamrock
Shamrock actually can’t be harvested and then regrown from seed.
The plant can only be propagated by using existing shamrock tubers or buying a shamrock plant from the local garden center
This plant doesn’t produce viable seeds, so you won’t find them for sale. Either find a neighbor or friend that can give you some tubers or buy one from the nursery to get it going.
There are two main ways to propagate shamrock. Read them and see which one suits your style!
Propagating by transplanting
You can propagate by doing it the old-fashioned way. Buy a shamrock plant then grab a new pot to transplant it to.
You’ll want to use a planter that’s similar in size (diameter). Check the depth of the original shamrock roots. You’ll want to replant it into a similarly sized pot.
Fill the new pot ⅔ full with a well-draining, nutrient-dense potting mix. Don’t use garden soil. The pot should be well draining with multiple drain ports so it doesn’t get clogged. Shamrock can’t tolerate wet feet!
Gently uproot the original plant by tilting the container to its side. You can water it if the soil is tough or hard. If the roots are rootbound, use sterilized pruners to cut them from the pot.
This will loosen the shamrock plant so you can remove it from the original pot. Remove the soil from the shamrock roots. You won’t be able to get it all off, but you can get most of it off by using water to loosen it.
Replace the soil with a new potting mix. Don’t use the original soil because it’s likely depleted of nutrients. Be gentle when doing any sort of cutting. Trim only as much as you need to.
Recycling the soil may also introduce pests to your new pot. This is why you should remove as much as you can.
Place the shamrock into its new home. The plant should be placed about half an inch taller than the original container.
This allows it to sit in over time because it’ll seep into place. Fill around the shamrock with new soil. Pat it down. Then water it!
Keep the container within temperatures of 60-70F. It’s preferred to keep it cooler than warmer. Water it daily, but don’t overdo it. It should be moist but never wet.
Place the container next to a sunny spot, but not directly in the sun. use dappled filtered light only.
Propagating by dividing
You can also easily divide shamrock from a neighbor’s plant. You’ll need a virulent, established shamrock to extract plant sections from.
The ideal time to divide is in the fall, usually from October onwards.
This is because the plant will produce so you can extract! Autumn is when new shoots appear and are good for dividing the tubers in the plant. You can get more shamrocks to give away or expand your collection.
Get high-quality, nutrient-dense, well-draining soil. I know. Everyone says that. But it’s because it’s THAT important.
Next, grab a potter that’s well draining and has at least a 5” diameter. The material of the pot matters.
Choose one that’s terracotta or ceramic. Pretty much anything that’s porous. This material helps minimize temperature swings, which can be harmful to younger shamrock seedlings.
Don’t use plastic. It quickly heats up and doesn’t retain heat overnight. The pot should have at least 3 holes to drain. Double-check that it doesn’t require you to drill them yourself!
Fill the pot with potting soil one inch from the rim of the container. Let the soil sit by shaking it so it evens out.
Water it so it’ll settle down even more. You can give it a generous watering for the first time so it can build water pathways.
Gently tilt the pot so you can unearth the plant. You only need to take out the top few inches of soil to see the shamrock roots. Find a tuber that’s at least 1” in diameter with complete roots on it.
If it has stems, that’s preferred so you know you’re pulling a tuber that’s ready to root. The tuber can be removed by gently pulling it away from the others. But if it’s too tangled, ignore it.
Wipe off any debris or soil stuck on it. Then place it into the new pot at 1” deep. Cover it with a potting mix, but don’t pat it.
You want it near the surface of the soil line because if it’s too deep, it’ll likely rot or grow fungus. Plus, shamrock doesn’t like to be wet. Moist is the name of the game.
Put the pot in temperate conditions near a sunny window. The light should be bright, but filtered sunlight that’s NOT direct.
How to grow shamrock
You’ll find that shamrock is a beginner-friendly houseplant that requires very little work. Here are some suggestions to maximize your shamrock’s size.
Got questions? Post your questions in the comments.
Shamrock grows well in USDA hardiness zones 8-11. If you’re planning on growing it outside in your yard, be sure that you’re within these zones.
Temperatures that are too hot or cold will make it enter premature dormancy, which can limit those pretty blooms.
Otherwise, if you’re growing it inside your house, then you’ve got nothing to worry about. The zone doesn’t matter for indoor houseplants. So plant on!
Use well-draining, moisture-retaining soil with plenty of organic nutrients.
You can find a potting mix in nurseries that can be combined with plant supplements in order to get it saturated with nutrients. In other words, if you can’t find the soil you need for your shamrock, make your own!
Use organic soil if possible. Shamrock can be sensitive to harmful compounds in the soil column. Get loamy, sandy, well-draining acidic soil.
The soil pH should be on the acidic side, with a pH range of 4.5-6.5 for shamrock plants.
You can raise the pH of your soil naturally using soil amendments. Potting mix for indoor plants usually fulfills this requirement.
While the pH won’t make or break your shamrock’s production, it can help spruce up the colors and overall happiness of your plant.
The seeds should be planted 1” from the soil line and lightly covered. If transplanting, it should be planted at the same root depth as the original plant. If growing from cuttings, plant at least 5 inches deep.
If you’re planting multiple shamrock tubers in the same pot, give them 3 inches between each to help encourage water evaporation and minimize competition for nutrients.
If you’re just planting one per pot, then space it at least 2 inches more than the longest root. It likes to be snug, but not too tight.
However, shamrock generally fares well when the root are confined so it can focus its energy on the production of blooms.
Keep shamrock between 70-80 F during the daytime. During the night, it can tolerate temperatures as low as 50F.
This plant is both sensitive to temps that are too hot and too cold, so keep it in the ideal range. Dormancy is a common sign of temperatures that are way too hot for shamrock to tolerate.
If this is the case, move it away from the windows so it doesn’t face overheating. Premature dormancy is common for shamrocks that are kept directly in the sun.
Shamrock prefers average, moderate humidity. Maintain levels between 40-50%. If the air is dry, you can use a humidifier or try placing it near wetter areas like the bathroom or kitchen.
You can also use a pebble tray with water or near a room humidifier.
For south facing windows, place them 2-3 feet away from the window on bright sunny days. It needs dappled light, never direct light. If it’s too sunny, it’ll get dehydrated and may even enter dormancy.
Yellowing or browning leaves, dry leaves, or stunted growth are signs that your shamrock is getting scorched.
Full or partial sunlight is OK, but it depends on your location. Hotter zones should use filtered sunlight only.
Water shamrock when the top inch of soil feels dry. Don’t let shamrock dry out between watering sessions.
While it has some degree of drought tolerance, it’s not excellent by any means. Soil should remain slightly moist during all periods. Water 2-3 times per month. The soil should nearly dry out between watering, but not completely if you have a well-draining pot.
If the soil is draining poorly, switch containers or let it dry out between waterings as a temporary solution.
Shamrock will benefit from nutrition in the soil but takes plant fertilizer as well. Feed your shamrock once every other week in the fall through spring.
When it produces its gorgeous blooms, feed more often using a liquid houseplant fertilizer.
You can dilute it with water to help reduce its strength of it so you can feed it more often. Most shamrocks will do OK without fertilizer, but if you want to produce the maximum of flowers, consider adding some plant food.
Use well-balanced houseplant food. Oxalis varieties will produce the most flowers when grown indoors.
Mulching isn’t necessary for shamrock. If temperatures dip below 40F, you can put a half-inch layer of mulch on the soil to help insulate it. Remove during the growing season. Only use sparingly for cold snaps.
Pruning should be done with a pair of sterilized scissors or pruners. Remove dead leaves or ugly ones.
Prune to keep it tidy and neat. Cutting back the leaves and spent blossoms are necessary for the summertime when it enters dormancy. Feel free to tidy it up by neatly trimming off yellowing or browning leaves.
Spent flowers should be removed so they can focus their energy on producing other flowers. Cutting it back will help encourage more flowering.
Shamrock requires very little maintenance once established. Just water it 2-3 times per month and give it some high-quality plant food during the growing season.
Cut off spent leaves or flowers during dormancy transition. That’s it.
If you want to keep it in good shape, there are some things you can do to help improve your shamrock!
Your plant will outgrow its first home (the 5-inch pot) and will need to be repotted into a bigger pot.
Oxalis doesn’t like too much space between the roots but doesn’t like crowded roots either.
Being rootbound is a good thing, but upgrade as needed. Snug, tight-fitting pots will limit the roots from growing, which then forces the shamrock to produce flowers and leaves instead.
So limiting the pot size is a good thing. When you start seeing the roots come out of the drain holes or compact on the edges, then it’s time to repot. Gently remove it by tilting the pot.
Dig out the soil being careful not to harm the roots. Then place the plant into its new home by sticking it into the center of a prefilled pot with the same or different soil. Fill the new pot 2⁄3 of the way up with soil. It’s also a good time to assess how the soil contents are.
If you want to experiment with other substrates, consider using a soil test kit to see what it’s missing/what it ate. Larger oxalis species can grow upwards of 24 inches wide and 18 inches tall. The smaller ones will max out at 6-8 inches.
When the foliage or stems have grown so dense that it becomes hard to water, it’s time to repot.
Visible roots that come out of the bottom are also another sign that it needs a bigger house. Increase the container size by 2 inches each time to ensure a snug fit. Keep the depth of the original container, but expand its diameter of it.
The roots will be shallow when you uproot them, so be very careful not to damage them.
Remove as much of the old soil stuck on the roots as you can. Settle the crown an inch higher.
The part where the shoots come out from the tubers should be about half an inch taller than the previous pot.
Try to keep the tubers together so it’s uniform. Fill it with soil to hold it in place. Water it well.
Shamrock can be stored between temperatures of 40-50F during the winter.
When the col has passed, the plant will resume blooming. Some cultivars will bloom throughout the winter time, so it’s a good choice for a plant that produces flowers even in the winter.
If you’re planting outside, store the bulbs indoors for the summer. Then in the spring, you can plant them outside with 1” of soil. Water well and expect foliage in a few weeks.
These plants will produce the most blooms indoors rather than outside. Note that if you take a native shamrock and try to plant it indoors, it usually won’t take it well.
Shamrock seeds aren’t viable for saving, so this isn’t an option. This is why you can only buy it from a nursery or use bulbs/tubers from an existing one.
Shamrock pairs well with other colorful houseplants. Although you should grow it in its own container, you can put it next to other houseplants like the Japanese Painted Fern, which makes a good companion to Oxalis triangularis in a perennial setup.
They both have purple, which can create a nice matching color. Amaryllis is another good plant because of its complementary colors. Taller houseplants can match with the shorter shamrock 6 inches.
Don’t plant with
Avoid planting with other houseplants that crowd or shadow the light it needs to thrive.
This includes taller houseplants with large leaves that just block out light. If you plan to put shamrock next to other plants, make sure it gets its sunlight.
Shamrock enters dormancy during the beginning of summer. This plant doesn’t like the heat, so whenever the temps pick up, it’ll go into sleeping mode.
It can also happen if there’s a heat wave going on or if you don’t water it enough. Sometimes wide temperature swings can also make it go into early dormancy.
The stems will drop and the flowers will sag. If you find that your shamrock randomly entered dormancy, you can stop watering and fertilizing. The leaves will turn yellow or brown over time.
Then they’ll drop off. Prune the foliage that’s dead. Relocate the pot to a cooler spot in your place. Then leave it there for the next month or so.
For natural dormancy, you’ll want to give a rest period.
Green leaf shamrock will usually stay dormant for up to 90 days. Purple leaves will sleep for 30 days.
When the new offshoots start to show up, it’s good to go again. Dormancy is over. Your shamrock is awake. Congrats. You can put it back to its original location, begin feeding and resume watering.
For dormancy stemming from stress or heat, follow the same steps. You can’t snap it out of dormancy. It needs to rest before it’ll produce. So let it be. Fix whatever the issue was that caused the dormancy in the first place.
The dormant period will vary depending on the cultivar and local growing conditions. As soon as you see the new shoots, then dormancy is broken. Resume care to get rewarded with those pretty leaves and plentiful blooms.
Choose a container that’s porous like terra cotta, clay, or stone. These materials help absorb and evaporate water so it doesn’t pool in the pot. Avoid plastics or pots that are nonporous.
Be sure it doesn’t have some special coating, such as glaze. This defeats the purpose. The container should be at least 5 inches wide with multiple holes to drain.
Shamrock can be grown outside similarly to how you’d grow it indoors, but time and time again, it produces more flowers and nicer foliage when grown out of direct sunlight in a cooler environment.
If you’re looking to grow it in your garden, you can do so if you’re in zones 8-11. In cooler climates, you can grow it inside and then bring it out in the summer for more sunlight.
Plant it in part sun and well-draining soil. You can even put shamrock outside for a few hours during the summertime for more sun.
The tiny bulbs can be planted in the fall or spring depending on your zone. It’s usually an indoor plant, but you can plant it outside if you’re in the right zone. Not too hot. Not too cold. It’s goldilocks.
Oxalis doesn’t have any pest issues for the most part. There are a handful of bugs that are commonly found munching on those precious shamrock leaves.
They’re usually thrips, whiteflies, vine weevils, blackflies, root bugs, mealybugs, spider mites, and worms. The majority of these bugs can be controlled by insecticidal sprays.
Keeping your plant inside your house will keep the bugs out. If you see aphids on it, remove them by spraying down your plant.
Shamrock is pretty hardy to most pathogens, but there are a few that you need to watch out for. First is ring spot. The yellow rings on the leaves is the common sign of it. It can be controlled by removed the plant from its container and removing the affected leaves/shoots with sterilized pruners.
Fungal rust is another issue. This looks like orange or brown spots on the leaves. Remove the plant an then wash it completely, then replace it. Fungicidal soap may work well.
The last issue is root rot. This is what happens when you water too much without having enough drainage. Water less and ensure that the soil isn’t compacted.
Other common questions about shamrock care
This section contains questions from readers that are commonly asked about Shamrock.
You may find it useful. After all, this is a care sheet!
Please ask your questions using the form at the end of the page. We’ll be happy to get back to you.
How often should I water a shamrock plant?
Water when the top inch of soil is nearly dry. Use your finger to check. If you’re unsure, use a moisture meter instead. This can accurately gauge the water content in the soil so you never overwater.
Do shamrock plants need direct sunlight?
It depends on where you live and the ambient temperatures. If you’re in zones 8-11, you should be OK to put it near a south-facing window.
The sun should be filtered regardless. This will limit sun exposure and prevent scorching or burning of the tips.
Do shamrock plants like to be misted?
Yes, they do. You can mist it to keep the ambient humidity up if the air is dry in your house. A light misting will keep it moist, but don’t mist in place of watering.
Where should I place my shamrock plant?
Plae it 2-3 feet from a bright window. It shouldn’t be in direct sunlight. Use filtered light only.
What happens when a shamrock plant goes dormant?
It’ll turn yellow or brown with leaf drops. It’ll also stop producing blooms. Dormancy can be heat or stress-induced.
Both of which will require a rest period before they’ll resume growing those precious leaves again. So give it time and learn from environmental stressors.
Do shamrock plants like to be root bound?
Rootbound shamrock tends to produce more foliage and blooms compared to shamrock which has plenty of space for the roots.
This is because a smaller pot forces it to stop growing roots and refocus that energy on the flowers and foliage instead.
Can you overwater a shamrock plant?
Just like any other houseplant, overwatering is a primary killer of shammies. Never overwater your shamrock.
Only water it so it’s moist but never wet. The soil should be well draining so none of the water gets stuck in the pot. Let it go dry between waterings. If you overwater, it’ll introduce fungus or mold.
Root rot is also common with wet and poorly draining substrates.
How do you keep a shamrock plant from getting leggy?
If your shamrock gets thin or leggy, cut it back! Consider moving it to somewhere that gets more light. Leggy stems come from plants that are not reaching for light.
Why are the tips of my shamrock plant turning brown?
The tips turn brown because it’s either not getting enough nutrients or there’s too much light.
Move it to somewhere that doesn’t get as much light. Supplement with a plant fertilizer. Remove the browned tips using sterilized pruners
Are coffee grounds good for shamrock plants?
Shamrock can benefit from acidic soil which can be facilitated through the use of coffee because it’s naturally acidic.
You can lower the pH of your soil using sprinkled coffee right into the soil surface line, but don’t overdo it.
Remember that the potted container is a “closed” ecosystem, so if you put too much coffee in there, it can build up over time. Use only if your soil is too basic or neutral.
How do you make a shamrock bushy?
Keep the roots snug in the pot and trim it when it gets too tall. This will force it to grow sideways instead which may help encourage it to get bushier. Plant food will also aid denser foliage.
When should I repot my shamrock plant?
You should repot your shamrock when the roots are too snug and either coming out on the bottom of the pot.
If there’s not enough space, your plant will start to produce fewer blooms. Repot to a larger pot 2” bigger in diameter than the previous one.
Keep the same height between the old and new pots.
Check out these sources for more detailed info about shamrock plants:
- Shamrocks, Oxalis spp. – Wisconsin Horticulture
- Shamrocks as Houseplants – Penn State Extension
Grow shamrock at home
Shamrock is a one-of-a-kind plant that’s overshadowed by the holiday. Grow it anytime in your household and share it with friends when the holiday does come out.
Enjoy those purple or pink flowers the rest of the time.
Given that it’s a summer dormant houseplant, you can enjoy the flowers the rest of the season when your other houseplants sleep.
Shamrock will be perked up and shining.
I’ve always been interested in gardening, but I never took it seriously until I was forcefully gifted an orchid. This was what got me into the hobby and I’ve never looked back. I enjoy writing about it, but not nearly as much as getting into the dirt and sculpting the perfect decorative ornamental to enjoy for the times.