Like any Calathea owner, you love your houseplant’s bold patterns. So you want it to grow lots of big, healthy leaves to show those vivid markings off as much as possible. Let’s talk about what you can do to get your Calathea to grow.
Encouraging growth in Calatheas mostly comes down to balance. These famously picky plants thrive in a fairly narrow range of environmental conditions, particularly when it comes to moisture and sunlight. The key factors are bright, indirect light, high humidity, and potting soil that stays damp but not wet.
You’ll probably have to experiment at least a little to nail down the right location and care regimen for your Calathea. That said, there are a number of common issues that get in the way of producing big and healthy foliage. This article will explain how you can correct these issues and kick your Calathea’s growth into high gear.
How Big and Fast Do Calatheas Grow?
Many people think of these plants as slow growers since they’re so temperamental about their growing conditions. But most Calathea species can actually shoot up rather quickly when their needs are met, reaching their mature height of roughly 2 feet within a year or two.
After that, they’ll get bushier but not taller. A happy Calathea will usually produce at least a few new leaves per month during the spring and summer. If you live somewhere with real winters, your plant probably won’t grow at all during the colder part of the year. It shouldn’t go fully dormant, though – if your Calathea drops all its leaves in the winter, it’s likely suffering from cold shock. You should move it to a less drafty spot.
Now we’ll go over some useful tips for getting the most growth out of your Calathea.
1: Provide Lots of Filtered Light
You might find this advice confusing if you settled on a Calathea after finding it on a list of low-light home or office plants. The problem here is that “low-light” is a relative term. Compared to sun-hungry plants like Aloe Vera or Hibiscus, Calatheas are indeed fairly shade-tolerant.
But that’s only because they don’t like sunbeams blazing right onto their leaves. In the equatorial jungles where they evolved, Calatheas receive plenty of illumination from the tropical sun, but it’s filtered by the canopy to reduce its intensity before it reaches them.
Your Peacock Plant is sensitive to sunburn, but it doesn’t want to sit in a dark room. If it seems to be struggling to grow, you may not be giving it enough light. This is especially likely if your Calathea’s formerly vivid patterns appear to be fading and growing pale. Give it a bit more solar power, and it should perk up quickly.
Try setting the Calathea near an east-facing window. That will offer it a few hours of bright light in the morning when cooler temperatures will reduce the risk of sun scorch. A room with lots of southern or western exposure can also work well, as long as you shield your plant with some sheer curtains or place it a few feet back from the nearest window.
2: Don’t Let the Soil Dry Out
Watering correctly is probably the most common challenge for Calathea owners. These plants don’t like the soil around their roots to dry out completely, but they also can’t have it too soggy, or they’ll start to suffocate.
Poor growth in Calatheas is often caused by underwatering. It may be accompanied by shriveled, dried-out leaves, as well as browning and yellowing at the tips and edges of the foliage. Overwatering also prevents growth, and over the long run, it could cause root rot – a potentially fatal condition.
Many houseplant owners like to water on a fixed schedule, but this is often counterproductive since the potting mix won’t always dry out at the same rate. Instead, you should check the soil regularly so that you know when the plant needs water.
The quick-and-dirty method is to poke a finger an inch or two into the mix and see if it still feels damp. If so, it’s not yet time to water. Once that top layer dries out, you can give your Calathea another drink. To get a little more precise, try sticking a chopstick or a moisture probe down near the pot’s base to see what the conditions near the roots are like.
When your Calathea does need water, give it enough that you see some trickling out the drainage holes at the bottom of the container. It’s essential to be thorough!
3: Avoid Using Tap Water
Along with watering too much or too little, you can hamper your Calathea’s growth by giving it the wrong kind of water. These plants are very picky about the mineral content of their soil, and tap water in many areas contains high concentrations of calcium and magnesium. Even the chlorine or fluoride in municipal water may stress out these high-maintenance beauties.
As with dehydration, this problem typically results in browning or curling leaf edges in addition to reduced growth. Try switching to distilled or bottled water when you hydrate your Calathea, and see if its health and growth improve. If you can collect enough rainwater to give the plant a thorough watering, that’s an even better option!
If you must water from the tap, it’s a good idea to fill up the watering can and set it aside overnight before using it. That will allow time for the chlorine to evaporate, making the water a little less harsh on your Calathea.
4: Provide the Right Potting Mix
This suggestion is actually a watering tip disguised as a soil tip. Giving your Calathea the ideal growing medium helps prevent both overwatering and underwatering. That makes it much easier to grow a big, beautiful plant.
Once again, you’re trying to strike a delicate balance. (Are you starting to see why Calatheas are considered so fussy?) The right soil drains quickly so that the roots don’t become waterlogged, but also contains absorbent materials that can stay damp for a while.
Unfortunately, the standard potting mixes in most garden stores tend to get too soggy for Calatheas. Perlite, a kind of porous volcanic glass, will help improve the drainage. Loose but spongy ingredients like peat moss or coconut coir retain some water to keep the mix from drying out completely, but they still drain better than standard soil.
Try a ratio of 40% coarse-grade perlite, 40% coir, and 20% ordinary potting soil. Not sure you’re up for making a custom blend? Look for a commercial mix designed for African Violets, which thrive in the same kind of soil as Calatheas.
5: Flush the Container
As we noted in Tip #3, accumulated minerals in the soil can stifle your Calathea’s growth. Tap water is one potential source of those elements; fertilizer is another. If your plant’s growing medium contains any store-bought potting mix, it almost certainly includes fertilizer, so salt compounds will leach into the soil over time.
Wash the minerals out of the pot every so often to keep them from building up. Once every 2-3 months, place your Calathea’s container in the sink or shower and run a steady stream of room-temperature water through it. Bottled or distilled water works best for this purpose. Keep going until 3 or 4 times the pot’s total volume has washed out the drainage holes in the base.
6: Keep the Humidity High
Calatheas are native to the steamy jungles of the tropics, and they like their air humid. If your plant is reluctant to grow, try boosting its humidity.
Clustering it with other Calatheas is one simple and effective approach. Plants in close proximity create a humid microclimate since they’re constantly releasing water vapor from their leaves. Group houseplants that have similar moisture requirements together.
Here are a few other humidity lovers that go well with Calatheas:
- Fiddle-leaf Figs
If your Calathea still seems to be struggling, it might be time to add a humidifier to your plant shelf. Here’s one that produces warm mist, which helps keep your rainforest plants comfortable in the wintertime.
You can also help by misting your plant frequently with a spray bottle (use a fine mist setting) or placing the pot on top of a shallow tray of pebbles and water. These methods aren’t as effective as a mechanical humidifier, though. You’d have to mist your Calathea several times a day to come anywhere near the output of a machine!
7: Move the Plant to a Larger Pot
Tight spaces don’t suit Calatheas well; when these plants outgrow their containers and become root bound, they’ll stop generating new foliage. It’s best to repot them into larger vessels once every 1-2 years. The best time of year is the early spring, when your plant is getting ready to put out new growth.
Don’t overdo it on the pot size. An extra 2 inches or so in diameter is probably enough. More than that will increase the risk of overwatering. It might also encourage your Calathea to spend all its energy expanding its root system instead of growing lovely new leaves. Give the plant a container with drainage holes in the bottom, and use a potting mix like the one described in tip #4.
Be prepared for your Calathea to show some signs of stress for a few weeks after repotting, but it should bounce back if you give it plenty of water and humidity.
We’ve saved this tip for last because it really is the last thing you should try. If you give your plant fertilizer when some other factor is preventing it from creating new growth, the chemicals you add will go unused and sit in the soil, potentially damaging your Calathea’s roots. Check the other growing conditions first!
Once you’re confident that your Calathea has enough light, water, humidity, and space to create new leaves, you can start a low-dose regimen of fertilizer. Once a month, dissolve a small amount of a balanced nutrient formula into the water you give the plant. Jack’s Classic All Purpose Fertilizer should work well; dilute it to a quarter of the strength listed on the tub.
Periodically flushing the soil as described in Tip #5 is even more important when you’re adding fertilizer. And don’t fertilize during the fall and winter, since your Calathea will almost certainly not be growing during the colder months.
Calatheas care is often tricky to get right, but when you strike the right balance, your plant will produce an abundance of lush, eye-catching leaves. A full-grown and healthy Calathea is a sight to behold – you won’t regret the effort you poured into keeping yours happy.