Cut all the leaves off the plant.
This is very much a drastic way to get rid of pests, but it does work.
Not, I should note, with all plants. It won’t do anything for fungus gnats, but it should remove, if not all, then a good 95% of spider mites, thrips, and mealybugs.
This is one of my preferred ways of dealing with pests in winter, because the plant isn’t really growing anyway, and new growth is often stunted or just a bit gnarly. By cutting the plant back it removes the pests quickly, without need for chemicals, and in the spring, the plant will be ready to bounce back.
If this is a bit drastic for you, I have an article about more traditional methods of dealing with house plant pests, and a more holistic method, which is what I tend to do in summer.
I have some plants that just have their leaves removed in November as part of their care. They’re gonna get pests (some plants are magnets) so there’s no point delaying the inevitable and also risking the bugs spreading to my other plants (ones that won’t bounce back as quickly).
I am, of course, talking about my Philodendron selloum. Those things bloody LOVE a thrips infestation. The thrips don’t really bother the plant itself (they have thick leaves, and I assume have evolved to support a small population of pests) but they do spread to my other plants.
Every Spring my Selloum goes outside where he grows bigger and beautiful than he did the year before. Aaaand then I cut him back again.
Cutting plants right back in winter
This isn’t something I do to many of my plants, but it is a great way to manage plant numbers in winter.
In summer, there are more places to put plants, so I always end up buying more. I put all my succulents outside in spring, then fill their spots inside with other plants.
When winter comes round again I’m all *surprised Pikachu face* that I have nowhere to put my succulents.
So some plants have their leaves removed, and are all put together somewhere (usually the bottom shelf of my plant shelves which is dark as heck) to chill until summer.
Putting them all together is helpful because keeping them in similar conditions means they’re more likely to all need watering at the same time, which makes life easier.
Since they have no leaves, they don’t need light BUT if any of them try to grow over winter (there’s always one renegade) you’ll need to move it to a brighter spot.
If you cut all the leaves of a plant will it grow back?
No. Not all plants can be counted on to grow back from nothing.
Don’t cut all the fronds off palms, for example, and expect it to regrow from the same spot, because it won’t. You might get some pups, but you won’t get the original plant to regrow.
Most Philodendron/Monstera/Pothos have no issue with being cut right back to the base.
In fact, having a big root system and nothing to sustain can result in multiple growth points. If the plant thinks it can sustain growing four leaves at once, it’ll give it a go. It’s not exactly a speedy way to grow a bushier plant, but it works if time isn’t an issue.
Ferns will need nurturing, and will benefit from higher light than normal, but you can get to grow from stump to full, decent-sized plant in a year.
I’ve been painstaking caring for my maidenhair fern, nurturing a pot of soil and roots up to a few dozen fronds, only to accidentally let it dry out so we’re back to square one.
How many times can you cut a plant right back?
As far as I’m aware, there isn’t a limit as long as you keep the plant well cared for, and you keep up the nutrient levels in the soil (I have a post here about re-energising older soil).
I had major issues with my Calathea in the form of thrips and spider mites. My Orbifolia got to such a bad state that I put her in leca (which is my equivalent of sink or swim). She started thriving, but then got thrips again. I’ve cut all her leaves off about four times now and she keeps coming back, a bit bigger each time.
You’re only really limited by how well you’re willing to care for what is essentially a pot of soil. you need to keep the soil moist like you would a regular plant, but without any signs from the plant to indicate its thirst level.
I use the light/heavy method to determine when to water, which is a fancy way of saying that I water it when it feels light. It’s not very scientific, and it’s one of those annoying things that you just have to figure out for yourself (because there’s no standard plant/pot/soil weight).
Don’t feel bad about chucking plants
Please remember that I look after plants as part of my job. I nurture pots of soil over winter so I can tell you whether or not it’s worth doing. BUT I 100% understand why people don’t want to do it. If you have plants because you love that lush green look, or they really help your mental health, then I totally understand why you’d want to just yeet a plant that has pests.
One last drastic step you can take
This one is truly drastic and only works about 10% of the time.
Cutting all the leaves off plants SEEMS drastic because it’s not something that we talk about much. In reality, this kind of thing happens to plants all the time – they get eaten, trodden on, and picked up and dumped by the wind all the time. They’re designed to survive, despite what Calatheas would have you believe.
But if you have a plant that you’re about to throw out, keep it outside for a bit until it’s 100% dead.
As I said, it doesn’t usually work, but it CAN.
I had a watchchain succulent that had mealybugs BAD. The plant has thousands of crevices and I just couldn’t shake them. It went outside last winter (around February) and will remain outside forever. You see, the plant in the pot survived, and is growing:
Yes, there’s a lot of gnarly old growth but that’s definitely new growth. There are also a few weeds that have grown in the pot too (you can see how much care I’ve been taking of it – literally none).
In January. In the freaking SNOW. But not only that, it freaking PROPAGATED ITSELF.
That’s just…growing on my flagstones. Again, in the UK, in WINTER.
I freaking nurtured this thing. Dabbing at mealybugs with surgical spirit for HOURS and all I had to do was abandon it to the elements.
It only really got going in the last couple of months, so I’m hoping this summer to have a lawn of watchchain succulents.
Honestly, the effort-free approach is definitely worth a go before you chuck it. And yes, succulents are pretty hardy, BUT you never know how hardy a plant is until you test it. Maybe you’ve got an evolved super-strong plant. I’m not saying that this is a good way to save a plant (it isn’t), just that you should try it until it’s DEFINITELY dead.