The Ultimate Stromanthe Triostar Care Guide
The Stromanthe Triostar is pink, variegated and less of a drama queen compared to others in the Prayer Plant family (called Marantaceae). What's not to love?! Not exactly easy care, but not (too) difficult either, once you know what they love. Prone to brown tips and crispy edges like the rest of her family, which you can fix. Find out below what they love, and how to fix common Stromanthe issues...
Can the real Stromanthe please stand up?
This gorgeous girl has some identity issues. She should be ' Stromanthe Triostar' but 'Tricolour' is often incorrectly used in NZ. Her full name is Stromanthe sanguinea 'Triostar'. However this is NOT the same plant as the Ctenanthe oppenheimiana 'Tricolour'. Once you know what to look for it becomes obvious which one you have. If you're unsure, you can see the differences between Stromanthe Triostar and Ctenanthe Tricolour here >
Although Calathea and Stromanthe are relations from the same Maranta family, she's not a Calathea (and Calathea Tricolour or Calathea Triostar don't exist).
Ctenanthe (left) and Stromanthe (right) showing one of the most obvious differences. On the Ctenanthe Tricolour (left), the line down the middle of the leaf (the midrib), is a clean 'pin-stripe' - and on the Stromanthe Triostar (right) you can see a blurred 'glow' either side of the midrib.
What temperature does Stromanthe Triostar prefer?
Like me, these girls are not a huge fan of the cold, but Stromanthe tend to be more cold tolerant than other prayer plants. Stick to above 15 degrees if you can overnight. Although they can put up with down to 5 degrees provided all other conditions are great, I wouldn't risk it myself.
Best kept warm, between 18 to 27 degrees during the day is ideal for the Stromanthe Triostar. You'll very likely need artificial heating to keep the house warm enough for your Stromanthe in winter, and although she'll dry out faster, it's best to shift her to the warmest room in house over winter. The general rule is if you're comfortable, they will be too.
What lighting do Stromanthe Triostar need?
Bright indirect light is the way to go - and the more light you give her the more variegation your plant can support - but no direct light as their thin, variegated leaves are more prone to scorching. In my experience more light doesn't mean more pink, but less light does mean more green.
Like other prayer plants, they move their leaves a lot! I love this about them. Towards then away from the light during the day, and sometimes folded up at night, exposing those hot pink undersides. Leaves can also move in response to water and temperature, such as curling up to preserve water when dry. I find the less compact your Stromanthe is, the more dramatic the movement is.
What potting mix is best for Stromanthe Triostar?
Don't get too caught up on this. You want an airy, free-draining mix, ideally one with no soil. A mix with a combination of air space for healthy roots that's not too dense, that's free-draining to avoid root rot, and provides slow-release water retention (but no slow-release fertiliser - more about that coming up).
You can DIY or use a plant-specific pre-mix. I used to DIY my own mix, but since discovering the Bioleaf custom blend potting mix I've found my Stromanthe do much better in that, so I don't mess around with trying to create my own these days.
Take your own habits into account also. If you're an under-waterer, add more to your mix that increases water-retention. If you're an over-waterer, add more free-draining, airy ingredients.
That Bioleaf blend I use combines fern fibre, orchid bark, pumice, horticultural charcoal, worm castings and more. If you do want to make your own, aim for roughly 1/2 free-draining and airy, 1/2 water retention.
When should Stromanthe Triostar be repotted?
When you bring a new Stromanthe home, it's best not to repot for at least 4 weeks unless the substrate is really bad. Even if rootbound I would not repot for a while. Stromanthe tend to need extra TLC when you change their conditions, and adding the stress of repotting on top of coping with a change in conditions could be too much.
They are shockers for throwing a wobbly when conditions change, so just baby them a bit at first and they should come right within a week or two. Best to start with a nice warm spot with bright, indirect light, and let them settle in there for a few weeks first, before changing anything.
They may sulk at first with either closed up or drooping leaves but warmth and light should see her come right quickly. Stromanthe tend to be more prone to transplant stress after repotting too, so I use this method when repotting mine: What to do (and what not to do) when repotting >
What are the watering needs for the Stromanthe Triostar?
Lightly, evenly moist is preferred. Definitely avoid wet feet or soggy soil or you'll risk the dreaded root rot. Don't leave her sitting in water, especially not drained water (as drained water has a higher concentration of mineral salts from water and fertiliser, which can also cause scorched leaves).
A good full drench and drain about once weekly in summer, and every couple of weeks or so in winter is about right, but it very much depends on your conditions and potting mix. There's no set schedule you can follow. Always judge it based on your plant, in your conditions.
If you don't have a clear pot and aren't confident when to water, grab a digital water meter which changes colour depending on the water level below the surface. I like the Crew Soil Sensor for small to medium pots.
Stromanthe often get under-watered for fear of root rot, however this instead causes dry, crispy leaf tips and edges. Another sign you've left it too long between watering is leaves that curl inwards to try to conserve water. They really don't like to fully dry out (although if humidity is high they handle drying out much better).
I water again when the potting mix is about 3/4 dry. I shifted mine to clear pots to make it really easy to see the water level, as water droplets condense on the inside, showing you where the water level is down to.
Water more often when growing, at warmer times of year, when the air is dry, and in brighter conditions. If you pick a good, free-draining potting mix it makes it difficult to over-water and reduces the risk of root rot, so if you're finding the substrate is staying wet on top longer than 24 to 48 hours after watering, consider repotting as that's a sign your mix's water retention is too high.
Should you top water or bottom water Stromanthe?
Top watering is better than bottom watering for Stromanthe, and I wouldn't recommend misting those delicate leaves. Stromanthe tend to be more salt-sensitive, making them more prone to fertiliser burn and reacting to excess minerals from tap water. Top watering helps flush out excess salts that build-up over time from water and fertiliser.
Using a low-salt fertiliser is recommended for the same reason (more coming up about fertiliser). Their root system sends out fine, delicate roots everywhere, so make sure to water so the entire potting mix is evenly saturated so all roots get both the water and minerals they need. This will not increase the risk of root rot. Also water heavily enough so water pours out the bottom of the pot, to flush out any excess salts.
Let your Stromanthe fully drain before returning to the saucer or cover pot. Drained water is higher in salts and you don't want your Stromanthe absorbing those back up again. If you do water into a saucer or cover pot, remove any drained water after about 15 minutes. The potting mix should be still be saturated enough not to re-absorb the salts.
Is tap water okay for Stromanthe?
Water quality can also contribute to leaf damage. Stromanthe can be sensitive to the mineral salts and chemicals in tap water. If you can, use rainwater or fish tank water instead. You can also treat tap water with AquaPlus to remove the chlorine instantly, or just leave water to sit uncovered for 24 hours so excess chlorine can gas off.
However if none of this is realistic for you, do use tap water (I often do for mine), and just top water heavily enough to flush out excess minerals left from the last time you watered.
Does water temperature matter?
Yes, like the rest of your indoor jungle, you should avoid cold water for Stromanthe. It can 'shock' and damage roots. The ideal temperature is around 20 degrees. At this temperature the water still contains a lot of oxygen, and it is the ideal temperature for roots to get to work pumping that fresh water and essential minerals around the plant. Cold water reduces water flow and hot water reduces oxygen.
Are Stromanthe Triostar pet safe?
Yes! It feels so nice to say yes for once to this question since so many indoor plants are not pet safe but yes, Stromanthe are pet safe and non toxic to animals and humans.
Stromanthe Triostar pro tips & problem solving
Keeping a Stromanthe alive isn't difficult, but keeping her looking good can be. If the conditions aren't great, those lovely variegated areas can quickly turn yellow or brown, and leaf tips and edges can go crispy or curl up. Here are the most common Stromanthe Triostar issues and how to solve them.
Why does my Stromanthe Triostar have brown crispy leaf edges and dry leaf tips?
Humidity is your friend! You want to maintain humidity at least above 60% for these girls to be their happiest, best looking selves. Provided you're not underwatering, or letting them go completely dry between watering, brown or crispy tips or edges is a very common sign your Stromanthe needs more humidity. If you have been under-watering and letting your Stromanthe go fully dry, that will also happen due to under-watering, so fix that first before you get a humidifier.
Low humidity is rarely an issue in a typical humid NZ summer, but a humidifier in Winter is almost essential in most regions, especially if you have a fire, heat pump, or DVS / HRV that can all dry out the air. Before you splurge on a humidifier - I use the cordless H2O plant humidifiers for my jungle - just grab yourself a hygrometer first. They are cheap and let you monitor both temperature and humidity to check if you actually need a humidifier.
Why does my Stromanthe Triostar have yellow leaves?
Like most plant drama, yellow leaves could be due to a few factors, but with the Stromanthe I find it typically relates to water or fertiliser. Most often from over-watering or inconsistent watering (letting her go too dry too long between watering).
Wet feet is a no-no for Stromanthe, so let all that water drain out before returning her to her saucer or cover pot, and keep her evenly moist rather than too dry, or too soggy or wet. Root rot is a risk from over-watering these girls (meaning you've watered again too soon), and yellowing leaves is a common sign of root rot.
Another cause of yellowing leaves (and declining health in general) in Stromanthe is fertiliser, or rather, a lack of it. Indoor plants rely on fertiliser for the essential minerals they need to live their best life. More about fertiliser coming up.
Use this guide for help fixing yellowing leaves: Help! Why are my plant's leaves turning yellow?
What is the best fertiliser for Stromanthe Triostar?
Definitely DO fertilise your Stromanthe Triostar. They are light feeders, but that doesn't mean no food at all! Look for a complete and balanced NPK fertiliser that provides all 12 essential minerals, that's formulated for indoor plants, and ideally one that's free of urea and chlorides, two common higher-salt ingredients.
The Weakly Weekly method is superb for Stromanthe no matter what fertiliser you use, where you feed lightly, every time you water, which both reduces the risk of deficiencies while also protecting from fertiliser-burn.
Two fertilisers I recommend for Stromanthe, and have used myself, are GT Foliage Focus and Dyna-Gro Foliage Pro. I also give my girls a once-a-month seaweed feed with BioPower Seaweed. A third very popular food is Plant Runner Indoor Plant Food which combines both an NPK fertiliser with seaweed so you can skip the seaweed step. All 3 are readily available in NZ.
Why do my Stromanthe Triostar leaves have 'wet patches'?
This freaked me out the first time it happened to mine. See that darker pink patch below? at the bottom of the front leaf? That's the Stromanthe version of Oedema. Normally caused by the roots trying to get rid of excess water, causing leaf cells to burst or flood with water and change colour due to becoming transparent. A sign of over-watering, misting, or a substrate that retains too much water.
The reason misting is an issue, is when conditions means leaves can't fully dry. I do not recommend misting Stromanthe. It doesn't increase humidity, is likely to cause water spotting on the leaves from the minerals in the water, and can lead to oedema.
Photo from Behnke Nurseries.
Care rating for the Stromanthe Triostar
I rate the Stromanthe Triostar a 2.5 out of 5. 5 being the most difficult. 1 being super hardy. I give her a 2.5 mainly because of her higher humidity requirements and tendency to go crispy with no humidity or under-watering. However once you get a humidifier (or if you have naturally high humidity), and once you get watering right, she'll come right and become much easier care. Also keep in mind when you first bring them home, it's normal for them to sulk.