Stromanthe

Stomanthe thalia 'Triostar'

Contents

1. Top Tips
2. Location, Water, Humidity & Fertilisation
3. The Reasoning Behind its Movement of Leaves
4. Common Issues
5. Origins, Temperature, Propagation, Repotting & Toxicity

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Top Tips & Info

• Care Difficulty - Moderate to Difficult
• Stromanthe are the most relaxed member of the 'Marantaceæ' family due to their resilience to short-lived droughts and slight neglect.
• Offer a bright location with the avoidance of direct sunlight or dry air; those that have red under-leaves can tolerate shadier situations due to the colour's functionality. Too dark areas will result in a lack of leaf-movements throughout the day and night.
• Allow a quarter of the soil to dry out in between waters, reducing this further in the winter.
• High humidity is a must, primarily while the radiators are operating, so introduce a pebble tray to provide a stable environment.
• Fertilise using a 'Houseplant' labelled feed every four waters in the spring and summer, reducing this to every six in the colder months.
• Keep an eye out for Spider Mites webs that'll develop under the leaves - click on the link for more information.
• Repot every two years using a 'Houseplant' labelled potting mix, and the next sized pot with adequate drainage. Water the soil 24hrs before tinkering with their roots to reduce the risk of transplant shock.
• Does your Stromanthe need a pick-me-up? Why not buy our top-selling Soil Mix to give your green friend a new lease of life? We have sold over 3,200 batches in the last year alone, so click here to find out more...

Location & Light - 🔸🔸

Stromanthe can thrive a whole range of indirect light levels. Avoid intense sunlight for more than an hour a day as it'll cause terminal damage to its leaves; sun-scorch symptoms include pale-yellow leaves, stunted growth and brown patches. If this has happened to your specimen, relocate it to a slightly darker location and remove severely affected areas. Although the already-damaged leaves will not return back to its former glory, new growth will be considerably greener if kept in good cultivation.

Water - 🔸🔸🔸

Avoid root rot by allowing at least a quarter of the soil to dry out in between irrigations, feeling the weight of the pot for confirmation. Reduce hydrations further in the autumn and winter months, allowing the top third to dry out before another irrigation. Under-watering symptoms include stunted growth, flower loss, wilting, crispy brown patches developing on its leaves, and gradual decline. These issues are usually down to too much sunlight or heat, a much needed repot or sheer forgetfulness. Over-watering symptoms include lower yellowing leaves, stunted growth, browned foliage, wilting or development of brown spots on its leaves. These issues are usually familiar with either too little light or heat, or overly soggy soil. If you feel that root rot is the case, be sure to click on this link for more info.

Humidity - 🔸🔸🔸

Create a humidity tray to provide a moist and stable environment for a long-lasting specimen. If the surrounding saturation is too low or the heat too high, its leaves may start to brown over and curl, especially in direct sunlight. Hose the foliage down from time to time to hydrate the leaves and keep the dust levels down.

Fertilisation - 🔸

Fertilise every four waters during the growing period before reducing this to every six in the autumn & winter. Although an 'All-Purpose' fertiliser will still do the job, we'd recommend using a specific 'Houseplant' labelled fertiliser as it'll support the vital thirteen nutrients that this species will need to grow.

This image shows a new rhizomatous shoot appearing above the soil line that'll develop into its own specimen.

What's the reasoning behind it's movement of leaves?

Not only will they provide a 'jungle-vibe' via their foliage patterns, but they also have a fascinating talent - nyctinastic responses. 'Nyct' refers to the nighttime (think about the word for 'night' in German, Nacht), whereas the 'nastic' refers to plant movement. The motor organs, or pulvinus for botanists, swell and relax depending on the time of day, acting as a valve below the leaf's base.

There are many different types of nastic responses that plants can make; all of which are caused by external factors or stimuli. Mimosa pudica has thigmonastic characteristics where the plant folds its leaves one by one to make itself look dead and unattractive. This way, the predators would at least think twice about destroying a spindly weed, as it appears to be underdeveloped and therefore nutrient deficient. With Stromanthes, however, it's not entirely known why they do this; some believe its to protect the leaves and conserve water, whereas others lean towards the idea of disinteresting predators. Either way, you can certainly agree that it's super fascinating to see the contrast of its positions between both night and day.

Common Issues with Stromanthe

Curled leaves and brown leaf-edges are the result of too little water or over-exposure to the sun. This genus is best located in bright, indirect settings, and those that haven't acclimatised to the harsh rays will show signs of sun-scorch and environmental shock. A splash of winter sunlight is acceptable as long as the soil moisture is regularly observed, with complete avoidance once summer comes along.

If the stems and foliage become brown and crispy, you may have to prune it all to entice new rhizomatous growth from the soil line. Cut any dead or dying stems to allow the new addition to develop from the soil line. Reduce the stems back to around 3cm (1 inch) from the soil, keeping the stumps dry to prevent the development of diseases. As long as you provide moist soil and a well-lit location, new growth will appear within a few months. Do not repot or separate the rootstocks during this time, as it'll lead to transplant shock and inevitable death.

Spider Mites are small, near-transparent critters, that'll slowly suck out the chlorophyll out of the leaves. Have a check under the leaves, most notably along the midrib, for small webs and gritty yellow bumps. Click here to read our article about the eradicating Spider Mites, along with some extra tips that you may not find elsewhere!

Root rot is a common issue with specimens sat in too moist or waterlogged soil for long periods. Symptoms include rapidly yellowing leaves, stunted growth and a rotten brown base. Take the plant out of the pot and inspect health below the soil line. If the roots sport a yellow tinge, you're good to go, but if they're brown and mushy, action must be taken immediately. More information about addressing root rot can be found on this link.

Too low humidity can cause browning tips with yellow halos on juvenile leaves. Although this won't kill your specimen, you may want to increase the local moisture to prevent the new growth from adopting these symptoms. Mist or rinse the foliage from time to time and create a humidity tray while the heaters are active to create a stable environment. The browning of leaf-tips on older leaves is wholly natural and is the product of extensive photosynthesis during its life.

Mould developing on the soil means two things - too little light and over-watering. Despite the harmlessness of the mould, it'll prove unsightly to most gardeners and is therefore removed once known. To remove, replace the top two inches of the soil for a fresh batch of 'Houseplant' compost. Either increase the amount of light received (no direct sunlight for the first few weeks to prevent environmental shock) or decrease the frequency of waters slightly. If the mould is accompanied by yellowing lower leaves, you may also have a case of root rot.

Too little light could cause the nyctinastic moments (folding of leaves) to only respond for a fraction of the day, usually accompanied by little to no new growth and gradual decline. Remember to provide a location that is at least bright enough to read a newspaper, and always avoid prolonged exposure to direct light.

One of the most robust species of the Stromanthe genus, the S. thalia 'Triostar.

Origins

Stromanthe is a genus of rhizomatous flowering plants that form part of the Marantaceæ family. Its name originates from Greek, translating to 'high winds' and flowers 'anthe', which possibly refers to how the seeds are dispersed via strong winds. The genus was first described in 1849 by German botanist, Otto Wilhelm Sonder, during a visit to Brazil.

The Distribution of Stromanthe in Green  &  S. thalia 'Triostar' in Red.

Temperature

15° - 27°C   (59° - 80°F)
H1a (Hardiness Zone 13) - Must be grown indoors or under glass all year round. Never allow temperatures to dip below 15℃ or permanent damage may occur in the likes of flower loss, stunted growth and yellowed leaves.

Spread

Up to 1m in both height and 0.7m in width. Once they either flower or reach maturity, growth will be limited to almost none that can take up to 10 years.

Pruning & Maintenance

Remove yellow or dying leaves, and plant debris to encourage better-growing conditions. While pruning, always use clean scissors or shears to reduce the chance of bacterial and fungal diseases. Never cut through yellowed tissue as this may cause further damage in the likes of diseases or bacterial infections. Remember to make clean incisions as too-damaged wounds may shock the plant, causing weakened growth and a decline in health.

Cut any dying stems to around an inch from the soil line, allowing new growth to develop from its rhizomes. In some instances, you'll have to remove all of the stems, leaving just a bare pot of soil. As long as you provide moist soil and a well-lit location, new growth will appear within a few months. Do not repot or separate the rootstocks during this time, as it'll lead to transplant shock and inevitable death.

Here is a rhizomatous growth that'll develop into its own stem in due course.

Propagation

Via Seed, Rhizome (Offset) Division or Stem Cuttings.

Rhizome or Offset Division (Moderate) - Separating the basal offsets into their own pot will not only expand your plant collection, but it'll also slow the process of becoming pot bound. The best time to divide is during the spring, with the pup's height surpassing 20cm (7.8 inches). Gently brush away some of the soil to gain better access to the pup's base (lower stem) where the roots will be housed. While using a clean pair of secateurs or scissors, cut the stem with at least two root strands attached to its base. Set the pup in an appropriate-sized pot with adequate drainage and a 'Houseplant' labelled compost. The ideal location would provide bright, indirect light and temperatures above 15℃ (59℉). Maintain evenly moist soil, allowing the top third to dry out in between hydrations. After a month or two, treat it like a matured specimen by using the care tips mentioned above!

Stem Cuttings via Water - (Moderate)

1. Choose the healthiest, most established sections that have no visible signs of pests or diseases. This propagation method can be taken from spring to summer, with the stem being at least 20cm (7.8 inches) in length with two or three leaves.
2. Cut directly below a node (leaf) using a clean knife to reduce bacteria count. Remove the lower half of the leaves and place the vines into a container of lukewarm water. Be sure to submerge at least one node into the water, or else the root development will be hindered.
3. The leaves must stay above the water line to prevent disease.
4. Replace the water weekly, using lukewarm water to avert shocking the cutting with cold temperatures. 
5. Once the roots surpass 3cm (1.1 inches) in length, it's time to pot the specimen.
6. Choose a potting mix - as long as it has a well-draining nature, most soils are fine. 'Houseplant' compost is best, but a multi-purpose compost with a splash of grit or perlite is also acceptable.
7. Use a 10cm pot that has good drainage holes - plastic or terracotta are both acceptable in this instance. Try not to over-pot the cuttings; blackleg occurs when the bottom wound becomes infected, typically caused by water-logging or a too-damaged wound.
8. Set the cutting into the compost, keeping the foliage above the soil line.
9. Avoid direct sunlight and offer good humidity by placing the potted plants into a transparent plastic bag with holes for the first couple of weeks. 
10. Open the bag every two days for half an hour for the prevention of disease. After a month of being placed in soil, remove it from the bag and follow the care tips provided above.

Flowers

Most Stromanthe may never flower indoors, due to the insufficient growing conditions. A large shaft will develop through the middle of each stem, where a flower will develop at the top. As soon as the individual stem blooms, it'll holt growth, allowing new rhizomatous growth to form beneath the soil line.

Repotting

Repot every two years in the spring, using a 'Houseplant' labelled compost and the next sized pot with adequate drainage. Hydrate the plant 24hrs before tinkering with the roots to prevent the risk of transplant shock. For those that are situated in a darker location, add a thin layer of small grit in the pot's base to improve drainage and downplay over-watering. Click here for a detailed step-by-step guide on transplantation, or via this link to learn about repotting with root rot.

Small swollen nodules will develop along the Stromanthe's roots which can store both water and nutrients (nitrogen mainly) for potential droughts. Do not remove them as it may lead to stress on the specimen. Spider Plants also have the same root mechanism, however, with the latter they'll develop into cylindrical growths, instead of near-perfect balls.

Book a 1-to-1 video call with THE HOUSEPLANT DOCTOR™ if you'd like a personal guide to repotting your houseplant. This will include recommending the right branded-compost and pot size, followed by a live video call whilst you transplant the specimen for step-by-step guidance and answer any further questions!

Pests & Diseases

Keep an eye out for mealybugs, spider mites, scale, thrips & whitefly that'll locate themselves in the cubbyholes and undersides of the leaves. Common diseases associated with Stromanthes are root rot, leaf-spot disease, botrytis, rust, powdery mildew & southern blight - click here to learn more about these issues.

Toxicity

Not considered to be poisonous by consumption of pets and humans; if high quantities are eaten, it may result in vomiting, nausea and a loss of appetite.

Retail Locations

Dobbies,  IKEA,  Blue Diamond,  Online Stores.

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