Calathea are known for being somewhat, er, picky, when it comes to care, but unlike the similarly (and rightfully) maligned peace lily, they get their fair share of pests.
This article will go through the pests they get, and how to get rid of them, and then I’ll do a section at the end all about how to reduce the chance of them getting the pests in the first place.
Full disclosure: all my Calathea now live in the terrarium (though there’s a corner of my bedroom that would be a PERFECT Calathea corner) because my care regime and their care requirements just don’t really fit (though I have been a LOT better this year).
One thing that really puts me off is their propensity to get pests, and their reticence to let me get rid of them.
I still have a funny feeling that next time I walk out of a garden centre it’ll be with an armful of Calathea though.
Are Calathea prone to pests?
Kind of, but also they’re not as bad as they could be.
Calathea are pretty attractive to pests, especially the velvet leaves ones, and the ones with white stripes (I have no idea why, but pinstripe Calathea are THE WORST for getting pests).
Weirdly, when I had a room full of Calathea, they were the only ones that ever got pests (spider mites or thrips, and one exciting winter, both at once).
They have medium to thin leaves which pests love, but I think they reason they can be prone to pests is that they’re often in the process of dying. When plants are stressed, they send out signals (which seems like a bad move tbh) and pests are like ‘what an easy meal’ and move in.
So I don’t think Calathea are naturally prone to pests, I think they end up getting pests because they’re always stressed.
Identifying Calathea pests
Thrips
Thrips looks like little black rice grains that move quickly (and they hop like fleas) and they larvae are little and green. They tend to hang out on new growth and on the underside of leaves.
I’m going to go right now and try to find one of my Ctenanthe lubbersiana to how you. That thing freaking loves thrips.
WHADDYA KNOW
I apologise for the blur, but was moving.
The larvae look like this:
Gross.
Spider mites
Spider mites are TINY and ideally you want them gone before they start making their creepy webs. Don’t confuse them for real spiders. Red spider mites are MUCH smaller (they just look like tiny, tiny dots). Once you can clearly see them, you have a full blown infestation on your hands. Instead, look for damage to the leaf.
The mottled appearance is pretty typical, as shown on the Alocasia above. On Calathea, you usually see that the purple underside of the leaf is no longer purple.
Mealybugs
Calathea aren’t typical mealybug prey, because they like something with a bit more of a succulent leaf BUT it definitely isn’t unheard of. They look like tiny creepy white monsters:
Aphids
Aphids are greenflies. I hate them. Best way to get rid of them is to kidnap a ladybird to eat them. They’re not that common on aphids, but they LOVE ferns and are a nightmare to get rid of.
How to get rid of pests on Calathea
There are loads of ways to get rid of pests, and it depends on what you can afford and is available to you BUT ALSO different things work for different people. There’s a whole subreddit dedicated to making fun of people that use neem oil, but it works for me!
The most important thing about getting rid of house plant pests is keeping consistent and not stopping until the pests are gone.
Pesticides
Loads of people search up house plant pesticide on Amazon and use that and it works. I’ve used them in the past (a baby bio one I think) but haven’t found them to be particularly effective, plus they’re not great to use indoors (because you’re releasing poison into the air) so I’m not a fan.
Neem oil
I spray (diluted) neem oil onto my plants before cleaning them, and I think it works ok. i have recently switched to castile soap, and I think it’s slightly more effective and smells like soap, unlike neem oil that smells like peas and gravy.
Castile soap
See above. It’s just pure soap with no additives. Add a drop to a spray bottle, fill with water and spray onto plants. I spray liberally and don’t wipe it off (because I’m lazy) and it doesn’t seem to damage the plant leaves at all.
Plain water
Spray your plants down with plain water every few days until the pests are gone. I’m not sure if it kills them or they just get sick of being waterboarded, but it definitely works, but you have to be VERy consistent and do it for weeks.
Predatory mites
This is a great option if you just want to throw money at the issue. They’re expensive but very effective and perfect if you prefer a more natural approach to your plant care. I have a full guide to predatory mites here.
Or, as I have in the pas, kidnap a ladybird.
Removing the leaves
If you really can’t be bothered to get rid of the pests, and you’d rather just chuck the plant, consider cutting the leaves back to the soil first.
Most houseplant pests live on the plant, not the soil (apart from fungus gnats, but they’re not actually house plant predators – they’re just annoying) so cutting all the leaves off forces them to look elsewhere (which is why we isolate plants when they have pests).
Is it drastic? Yes. But it does work, and is super low effort.
How to reduce the chance of your Calathea getting pests
Clean the leaves
Spider mites are probably the pest most common to Calathea and they LOVE dust. Since Calathea are typically kept in low-light areas and have big, round leaves, they tend to attract more dust than other plants (which is possibly why they always seem to have spider mites)
You don’t need to spray the leaves with anything (though neem oil is a good shout) – just use a microfibre cloth to dust them every week or so.
I dust more in winter, because that tends to be when the pests move in, but try to keep them clean in summer too (genuinely cannot remember the last time I dusted my plants, other than a quick wipe with my sleeve when I’m taking photos).
Keep them healthy
This is the main one, and it’s not that difficult once you know what they’re after.
- Keep them warm – don’t put them in rooms that regularly get down to 15˚C/60˚F
- Keep humidity up – 60% or higher
- If they have crispy tips (which thrips LOVE – young/dead leave are great, they’re less bothered about anything in between) try filtered water
- Don’t let them get too dry or too wet – water when they hit a 3 on the moisture meter.
Final thoughts
It seems like Calathea are pretty predisposed to get pests, but I think it’s more that they’re tricky to take care of. Unlike, say, my Croton or Ctenathe that are both perfectly healthy and growing well but are still covered in spider mites and thrips respectively. The croton has been relegated outside because I’m just not feeling a spider mite infestation right now .