Thrips and Monstera are best friends, and it’s a toxic relationship we need to eradicate asap.
There are dozens of methods of getting thrips off Monstera, and I’ve tried all the ones available to me.
By far the best for many reasons is predatory mites. I will explain why later, but in short, they’re super easy to implement, they’re not harmful to anything but thrips, and they WORK.
No thrips elimination method is cheap, easy, and effective.
You can only have two.
My vote will always go for easy and effective. Throw money at the problem.
Why are thrips so hard to get rid of Monstera?
- They become immune to most pesticides
- You can be dealing with several generations at once
- They’re incredibly adaptable and can survive in adverse conditions
Are Monstera deliciosa prone to thrips?
In my experience yes, BUT from what I’ve seen online, Monstera tend to be afflicted by either scale OR thrips.
I assume that the environment will determine which pest you get, but thrips seems to be the more numerous pest.
They’re harder to eradicate than scale but take longer to do significant damage, so I think I’m glad I got saddled with thrips.
Thrips don’t tend to kill Monstera. They can easy take over other plants and reduce them to nothing but a sad stem, but with Monstera, they take their time. They’re also happy living on them, and therefore difficult to shift.
I’ve actually found it easier to just…assume my Monstera has thrips. I check them often, and regularly hose them down with a bit of soap just in case. It’s not a bad habit to get into, but it’s also not enough to get rid of an infestation (though it can keep it mostly at bay).
Signs of thrips on Monstera
There are quite a few different signs that your Monstera may be hosting thrips:
Adult thrips on your Monstera
I mean, this is the most obvious BUT they’re sneaky little devils.
When you have a few trips, the adults are pretty easy to see – they like to hang out on the back of the leaves with their babies.
They look like long, skinny…bugs.
Thrips have wings but they’re not great fliers. They just do a fancy jump, aided by air movement.
They’re usually black, though my Monstera dubia was recently playing host to some yellowy/brown ones. Yay.
However, when you start treating your Monstera, they start to get sneaky. Thrips are NOT stupid, and they know how to hide.
They like to lay low in the petiolar sheaths of your Monstera. That’s the weird indent in the petiole that housed the next leaf.
They can also crawl right into the crevices between the stem and the petiole.
Thrips lay around 100 eggs in one go, and then tend to move on (one leaf isn’t going to feed thousands of thrips) so I’ve found that squishing the adults is the best way to get rid of them. Concentrate on using treatments for the larvae, but squish the adults when you see them.
Larvae presence
Thrips larvae look like little white/green/yellow worms. They do move, but not very quickly. They can be found on their own or in groups.
You can’t see thrips eggs – the adult thrips will bite a hole in the leaf and lay their egg in there. That’s one of the reasons thrips are so hard to eradicate – the eggs are actually inside the leaf.
Black spots on the leaves
Little sticky black spots on the backs of Monstera leave are often thrips poop. You can wipe it off, but it won’t harm your Monstera.
Yellowing leaves
Thrips damage can take a few different forms depending on the plant, but on Monstera it causes a yellowing of the leaf that looks a bit like someone attacked it with an eraser.
Bronze patches on the leaves
Thrips leave quite distinctive bronze patches on the leaves. If you look in the top right corner of the picture below you can see what I mean
Brown patches on the leaves
Over time thrips will suck all the juices and life out of your Monstera andl leave you with dead patches on the leaves. Whoop.
Do thrips live in Monstera’s soil
Technically, yes.
Thrips spend their pupal stage on the soil or lower leaves of the Monstera. They don’t eat in this stage, so they don’t do any damage.
In my experience, the majority of the pupa stay on the leaves, and only a couple drop into the soil.
I don’t think it’s worth doing a soil drench or changing the soil – I think that that can cause unnecessary stress to your plant that can benefit the thrips.
How to prevent thrips on Monstera
Keep the leaves clean
Monstera leaves are devils for collecting dust so it’s a good idea to keep them clean anyway. I’m a big fan of cleaning Monstera leaves with those microfibre makeup-removing cloths.
You can use something like neem oil or castile soap to further prevent thrips from sneaking in without you noticing.
Dust can weaken Monstera by preventing them from photosynthesising effectively. It not only reduces the amount of light that can get to the leaves but it can also block the stomata, preventing the las exchanges necessary for photosynthesis.
Keep the Monstera healthy
I know this sounds like it’s too general of a statement to be of any use but it’s also…true.
Thrips are attracted to the stress hormones that Monstera release when they’re stressed. Monstera aren’t particularly easy to stress, but make sure:
- Your Monstera is getting enough light
- Its roots are healthy
- It’s not too cold
Further reading:
- How to care for Monstera deliciosa
- Light requirements for Monstera deliciosa
- How to save an overwatered Monstera
Add silica when you water
Adding silica to your water can help your Monstera protect itself from thrips. Silica makes the cell walls thicker and therefore more difficult for thrips to eat.
The first things you should do when you see thrips on Monstera:
Wash the plant down
You can either hose it off outside or in the shower. Get rid of all of the adults and larvae that you can see.
It doesn’t matter if it’ll be a couple of weeks before you can get treatment. Keep the leaves clean with a damp cloth and the thrips won’t get any worse
Isolate the plant
Thrips spread quite rapidly but they do like Monstera so they might not have gone far. Keep it in a different room from your other plants, but be sure to keep a close eye on all of them.
I keep my thrips-infested plants in the bathroom so I can check them when I’m brushing my teeth.
Cut off any damaged leaves
Remove any particularly bad leaves. They will likely be full of eggs. You don’t want to remove too many, because leaves are needed for photosythesis, but get rid of any that are more than 50% browned.
How to get rid of thrips on Monstera
As I’ve already mentioned, I’m a predatory mites girl. I love that you just dump them on the leaves and your work is done.
Predatory mites
I use amblyseius cucumeris, but amblyseius swirskii are another option. They eat the eggs and larva of the thrips, so you’ll have to squish the adults yourself.
Pros of predatory mites:
- So little effort on your part. You can even set up a subscription so you get the mites delivered every six weeks
- You can feed them pollen so you can establish a breeding colony so you never have to worry about thrips again
- They won’t harm anything other than thrips
- You can barely see them – they look like tiny dots whizzing about on your Monstera’s leaves
- 10,000 mites (for £9.99) got rid of my thrips infestation on 20 or so plants in about two weeks
Cons of predatory mites
- The idea of releasing bugs into your home is weird but I swear, you won’t notice them unless you really look
- They’re a pricier option, but not prohibitively so unless you live somewhere where they’re not readily available
- You need to wait a couple of weeks after using pesticides because…otherwise they’ll die
- They don’t like cold temperatures (it’s species dependent, but swirskii don’t like to go below 12˚C)
There’s some more information on using different predatory mites on different pests here:
Systemic pesticides
Systemic pesticides are an incredibly popular option, but they’re not available in the UK (well, they are, but they were banned, so aren’t easily available).
You add granules to your soil which your Monstera will absorb. When a thrips takes a bite, it’ll be poisoned.
Pros of systemic pesticides
- Easy to implement – just water them into the soil
- Easily available, reasonably priced
- Lasts about three months
Cons of systemic pesticides
- Banned in a lot of countries due to their impact on wildlife
- Potentially harmful to pets if they bite a leaf. There isn’t enough research done on systemic pesticides and aroids for me to trust having them around pets
- They’ll kill all the life in your soil, like springtails
- Thrips become immune to them. They won’t work forever
As you can tell, I’m not really a fan. I prefer a more holistic approach to pest eradication.
There’s more information on systemic pesticides here:
Insecticidal soap
I’m a big fan of insecticidal soap. It’s a nice compromise between treating your Monstera for thrips naturally, and just nuking it with whatever you can find.
I use castile soap (like dr Bronners) but dish soap/washing up liquid works as well. Add a small drop to a spray bottle and fill up with water. Spray your Monstera down thoroughly twice a week.
Monstera deliciosa are incredibly tolerant of this, and can take three sprays a week, but it can damage the leave, so err on the side of caution.
Pros of insecticidal soap
- Easy to get hold off, pretty cheap
- Kills on contact. Sometimes
- Fairly gentle on your plants
Cons of insecticidal soap
- You need to spray your Monstera down consistently twice a week for AT LEAST a couple of months, if not more
- Thrips can become, if not immune, definitely more tolerant of it, and you might find it gets less effective over time
Neem oil
Neem oil is better used as a preventative, so use it to clean your Monstera’s leaves. It can be an effective thrips treatement, but it can take a few weeks to work
Pros of neem oil
- Stops thrips from eating and reproducing (it interferes with their brain function)
- They don’t become immune
- It can kill larvae on contact, but not reliably
- Pretty natural – get the cold-pressed stuff
Cons of neem oil
- It smells weird
- It takes a while to work
- It can cause burning on the leaves
- It can affect pollinators, so don’t use it outside
Topical pesticides
These are products that contain spinosad or deltamthrin, so Captain Jack’s Dead Bug Brew and Provantos. The application methods vary, but it’s usually a spray.
Pros of topical pesticides
- They work (sometimes)
- Easy to get hold of, reasonably priced
- Easy to apply
Cons of topical pesticides
- Thrips can develop immunity
- Excessive usage can damage plants
- Can cause issues with mammals. Anything the size of an adult human is fine, be careful with anything smaller – i.e. don’t use it around kids and pets. And wear a mask
- It’ll take out the good guys too
Thrips-fighting add ons
These things won’t get rid of thrips for you, but they’re handy to have around to make other stuff more effective.
Blue sticky traps
I don’t consider blue sticky traps to be a thrips treatment – they’re more of an optional add on. They’re a great way to boost the effectiveness of other treatements and can help slow the spread of thrips to other plants.
I don’t use them, because I don’t want my predatory mites to accidentally get stuck to them
Hydrogen peroxide
I haven’t really had any success using hydrogen peroxide as a long term thrips treatment – I prefer it to treat root rot.
That being said, if you don’t have anything else, hydrogen peroxide can help slow down the infestation. You can also use it as a foliar spray or as a soil drench to get rid of thrips pupa in the soil.
I’ll link an article below with the dosages you’ll need.
Diatomaceous earth
Diatomaceous earth is very fine sand-like stuff that you can lay on top of the soil to stop the adults emerging from the soil where they’ve lived as pupa.
It’s incredibly sharp and will literally shred the thrips IF (big if) it’s bone dry. It’s doesn’t work when it’s wet.
Diatomaceous earth is incredibly effecitive but also…it’s hard to keep it dry enough to work.
On the plus side, if you do water it in, it’ll release silica into the soil, which your Monstera can take up and use to make super thick, thrips-proof cell walls. So whilst I wouldn’t rush out and buy it especially for thrips, it can be worth a try if you already have some.
It is good for fungus gnats though.
Can Monstera deliciosa survive with thrips?
Yes. I see a LOT of people advising to immediately throw out thrips-infested Monstera, but they can be treated. You may need to cut off a lot of the foliage, so often it’s easier to just buy a new plant But if your Monstera holds sentimental value then you can eradicate thrips.
I recommend you buy some predatory mites and pour them onto your Monstera’s leaves. Monst of the larvae will be gone in a couple of weeks. Replace the mites after six weeks, and keep repeating until the thrips are gone.
I hope you found this article helpful. If you have any thrips eradication tips, please leave them below.
Before you go, you might find these articles interesting:
- The Ultimate Guide to Monstera Deliciosa
- How to Care for Monstera Deliciosa
- Guide to Monstera Problems
