The Calathea lancifolia, better known to most indoor gardeners as the rattlesnake plant, is an enchanting and beautiful plant to grow indoors. Follow the care instructions below and by the time you’re finished reading this article, you’ll know how to care for the rattlesnake plant so yours will grow into a healthy and thriving houseplant.
The rattlesnake plant requires consistently moist conditions, indirect light, well-draining soil, temps between 65-75°F, humidity at 50% and up, fertilizer during its growing season, and repotting about every two years on average.
This full guide to rattlesnake plant care will provide all the information required to grow a thriving Calathea lancifolia, so don’t miss it!
Rattlesnake Plant (Calathea Lancifolia) Care
Watering the Rattlesnake Plant
Let’s get one of the most difficult areas of care out of the way first, and that’s watering your rattlesnake plant.
Calathea lancifolia prefers consistently moist or damp soil.
I say this is a difficult care area because some indoor gardeners can leave moist territory and enter the waterlogged zone with surprising ease.
When providing your rattlesnake plant with the ideal amount of water you’re aiming for soil that’s consistently moist or damp.
Moist soil will feel damp when you touch it but not enough water to create puddles of standing water in the soil.
Indeed, I do recommend you get used to touching the soil, inserting a clean finger or two into the dirt to feel whether it’s moist, drying out, or approaching bone dryness.
In the spring and summer, when the days are hottest for many regions and water can absorb more readily, be prepared to water the rattlesnake plant fairly regularly.
By the autumn, you’ll scale back, and in the winter, you’ll water even more seldom. You can allow the topsoil to dry out and then replenish the plant with water.
This careful balancing act is required so that Calathea lancifolia isn’t at risk of root rot, a fungal disease caused chiefly by overwatering.
For more information on ways to prevent your Rattlesnake plant from succumbing to root rot, I recommend you also read my article How to Prevent Root Rot in Potted Plants.
The rattlesnake plant is especially susceptible to standing water, which seems cruel considering it needs moist conditions, but it is what it is.
That’s why the fingertip test is so valuable, as you’ll have an accurate gauge no matter the season about how moist the plant’s conditions are.
The Correct Lighting for the Rattlesnake Plant
Calathea lancifolia does best in medium, indirect light.
Another Calathea plant that also loves medium, indirect light is the Calathea Medallion Plant.
For plant care tips on the Calathea Medallion Plant, I suggest reading my related article titled Calathea Medallion Plant Care: An Essential Guide.
That’s different than bright, indirect light, by the way, which is a more common requirement for many indoor plant species.
You can position the rattlesnake plant in front of an easterly-facing window, but the plant must be between six and eight feet away to prevent it from getting too much light.
Avoid southerly-facing windows especially, which are way too harsh for this plant. These windows get the bulk of the midday sun, which is when the sunlight is strongest.
If your rattlesnake plant is receiving just enough light, it will maintain those bright green crimped leaves with the dark, oval-shaped areas of coloration.
Should the light be too harsh, you’ll notice side effects such as drooping leaves and discoloration that will begin as yellow spots and can quickly turn brown, dry, and crispy.
Here is a picture of my healthy Rattlesnake plant’s leaves up close. Proving the proper light to your plant will bring out saturated colors on its leaves. Too much light can wash out the deep rich colors.
Soil Requirements for the Rattlesnake Plant
To prevent waterlogged conditions that would be disastrous for it, the rattlesnake plant needs well-draining soil.
A standard potting mix suffices just fine. You could even use slightly sandy soil, although be aware that it will dry out faster than potting mix.
You’ll have to be diligent about how often you replenish the sandy soil with water yet avoid overdoing it on the watering.
A neutral pH for the soil is fine. It’s even better if the rattlesnake plant’s soil is moderately acidic. Do be sure the soil doesn’t lean alkaline or basic.
Keeping the soil well-draining is doable with the inclusion of soil amendments.
Perlite and peat moss are two recommended amendments for the Calathea lancifolia, so let’s talk about both now.
The high water content of perlite, a type of volcanic glass, makes it a frequently recommended soil amendment for indoor plants.
The rattlesnake plant’s soil will stay moister (but not soaking) for longer with perlite.
At the same time, the presence of perlite in the soil allows for aeration since the volcanic glass creates air pockets for water to travel.
Peat moss will increase the acidity of the soil, which the rattlesnake plant will appreciate. This mossy soil amendment also holds moisture in drier soils such as sandy soils.
You can also count on peat moss to keep the structure of the soil nice and soft, which will in turn encourage better drainage.
Pot Requirements for the Rattlesnake Plant
The Calathea lancifolia needs at once moist but well-draining soil, which means not any type of pot will do.
I’d recommend a glazed clay or ceramic pot.
Without a layer of glaze, ceramic or clay would be too porous to be a viable option for the rattlesnake plant, but the glazing reduces the porosity of both materials.
If you still find that the water is draining or being absorbed too quickly, then add a plastic liner to the bottom of the pot. Plastic is nonporous and will retain moisture.
The rattlesnake plant’s pot should have drainage holes.
Temperature Requirements for the Rattlesnake Plant
The rattlesnake plant likes a room-temperature environment with temperatures anywhere from 65 to 75 degrees Fahrenheit.
There should be no need to bump your thermostat up or down whether at work or at home for the Calathea lancifolia, as its temp preferences are pretty comfy for the average person.
This plant prefers steady temperatures, so avoid fluctuations as best you can.
This is a good time then to remind you to watch your placement of the rattlesnake plant.
If the plant is positioned by a gusty door or window, a return vent, a radiator, or even your refrigerator, those air gusts will affect the temperature and make your plant unhappy.
Another way to avoid temperature stress is to prevent the rattlesnake plant from being exposed to its upper or lower temperature limits.
Anything lower than 60 degrees is officially too cold for the rattlesnake plant while temps that climb too much over 75 degrees will cause duress as well.
Temperature stress manifests differently in plants depending on whether the plant is freezing or burning.
You already know some of the symptoms of a burning rattlesnake plant, but what happens if the temps get too low?
The plant will droop, stop its active growth, and begin to turn yellow. That discoloration, if prolonged cold exposure occurs, could lead to blackening leaves from dead tissue.
Humidity Requirements for the Rattlesnake Plant
The rattlesnake plant isn’t too picky about its humidity just as it isn’t about its temperature, preferring humidity at around 50 percent.
That’s higher than some of the plants related to Calathea lancifolia, so if you’ve grown those before, be forewarned.
Humidity over 50 percent is just fine for this plant if you can swing it!
Most offices and buildings have an average relative humidity of between 30 and 50 percent. If you don’t already own a hygrometer, you can test the humidity where you live or work. It’s worth doing.
Low humidity will lead to a dry, brittle Calathea lancifolia, so be sure to amend the issue.
One option is to move the rattlesnake plant to the bathroom, but only if your bathroom a.) has a window that provides the right kind of lighting for the plant and b.) has the space.
If not, you can always buy a humidifier and use that instead.
Fertilizing the Rattlesnake Plant
When the spring begins, the rattlesnake plant starts to bloom, and that’s when this plant needs fertilizer for the first time all year.
A general houseplant fertilizer is fine, as is a balanced liquid fertilizer.
The fertilizer should include iron, which encourages the production of chlorophyll as well as photosynthesis.
You only need to fertilize once a month in the spring and then into the summer as well. When summer ends, stop fertilizing until next spring.
Pruning the Rattlesnake Plant
There’s no need to prune the Calathea lancifolia any more often than you would a standard indoor plant.
In other words, when the plant grows overly large or it has some dead or dying bits, it’s a good idea to start pruning.
You can use a standard pair of pruning shears or gardening scissors for the job. Whichever tool you choose should be adequately disinfected through either a rubbing alcohol or bleach bath.
When removing yellowing or browned leaves, don’t trim the leaves themselves. Rather, go down to the base of the leaf where it connects to the stalk and cut there.
If you must trim by a healthy leaf node where new growth will someday appear, leave at least a quarter-inch of space above the node so it can continue growing uninterrupted.
Make sure to follow the golden rule when pruning indoor plants, which is to never cut more than 1/3rd of your plant.
If your rattlesnake plant has so much dead and decaying foliage that you need to cut more, then it’s time to reevaluate its care routine.
Repotting the Rattlesnake Plant
There’s no need to make upgrading the rattlesnake plant’s home a frequent occurrence. Due to the plant’s growing speed, you can wait as long as two years before you repot.
In some cases, three years is appropriate, but make sure you’re looking for signs that the Calathea lancifolia has outgrown its pot.
If you see emergent roots in the drainage holes or right underneath the soil, those are some pretty big signs that the rattlesnake plant needs a bigger home!
The best time of the year for repotting the rattlesnake plant is before its active growing season begins.
The new pot should be at least two inches bigger than the old one and up to four inches bigger depending on how much your plant grew since it last was repotted.
The pot needs to be plenty wide to encourage the rattlesnake plant’s roots to spread out and grow.
Rattlesnake Plant Pests and Diseases
Pests are unfortunately a frequent consequence of growing a plant in your home or office. The good news is that Calathea lancifolia does not attract many insect species.
The ones you’ll have to beware of are as follows.
- Spider mites: The microscopic spider mite is known for weaving thick white webs underneath the crinkled leaves of the rattlesnake plant. The insects sustain themselves on plant juices, so don’t hesitate to rub a combination of water and isopropyl alcohol (one part of each) on both sides of the leaves to treat the mites.
- Mealybugs: Another thirsty sap drinker is the mealybug, which prefers the same moist, warm environment that the rattlesnake plant does. Mealybugs also aren’t fond of rubbing alcohol, so putting some on a cotton swab (make sure the stuff contains at least 70 percent isopropyl alcohol) and then dabbing it on the bugs will kill them.
- Aphids: Aphids like to cluster in large numbers on indoor plants and then suck the plant’s juices dry. Before it gets to that point, stop aphids in their tracks by spraying them with soapy water.
So what about plant diseases? Well, Calathea lancifolia is susceptible to only one, and I talked about it a little earlier.
I’m referring to fungal root rot.
Root rot is a common plant disease that kills a plant from its roots upward. Waterlogged conditions cause root rot, whether that’s from improperly draining soil, overwatering, or a combination of the two.
If your plant has fungal root rot, you can treat the rattlesnake plant in its current state and amend its care.
To treat the plant, remove the Calathea lancifolia from its soil and assess the root ball. You will see a slew of dead, decaying roots if the case of root rot is particularly bad.
These roots will smell too, so be ready for that!
Using clean pruning shears, remove all dead roots but leave the white ones intact.
Next, remove the plant’s water-soaked soil and add fresh, well-draining potting soil.
Moisten the soil as the rattlesnake plant likes it and only water when the soil dries out.
Rattlesnake Plant (Calathea Lancifolia) FAQs
Do you still have some questions about the Calathea lancifolia or rattlesnake plant? That’s just fine, as I’ve got answers!
Where Is the Rattlesnake Plant Native?
The rattlesnake plant’s original home is Rio de Janeiro, Brazil.
There in warm, moist, forested conditions, which explains why the rattlesnake plant requires so much humidity but not too much sunlight.
How Large Does the Rattlesnake Plant Get?
The Calathea lancifolia can reach widths of three feet and heights of five feet, although indoors, your plant will likely end up smaller by the time it reaches maturity.
When the rattlesnake plant grows, its growth pattern has been likened to a fountain.
Is the Rattlesnake Plant a Fast Grower?
The rattlesnake plant does not grow quickly, which is why you can go so long without repotting it.
The brighter its conditions are, the more accelerated the growth, but the plant still only requires moderately bright light.
Is the Rattlesnake Plant Toxic to Pets?
If you choose your indoor plants solely by whether they’re toxic to your four-legged friends, stress not. Calathea lancifolia is nontoxic to cats and dogs!
Is It Normal for the Rattlesnake Plant to Have Purple or Red Foliage?
Yes, and besides its beautiful, natural leaf patterning, you might also see the odd purple or dark red leaf on the rattlesnake plant.
If so, this is a sign that your plant is healthy. These leaves need just the right amount of light to retain their color, so you’re caring for your plant well!
Does the Rattlesnake Plant Grow Flowers?
The Calathea lancifolia produces beautiful blooms in an appealing yellow shade late into the spring when growing in its native Brazil.
Grown indoors though, the rattlesnake plant is not likely to grow these flowers.
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