How to get rid of house plant pests
Fuckin’ house plant bugs.
Out there shamelessly eating my plants.
Pests are a pain, especially to me, a vegan. I don’t WANT to kill them, but they insist on eating my plants. So I have to take a lot of preventative measures, which is far more time consuming than just nuking a plant with bug spray, but needs must.
This is not important to you. The rest of the post will be. Supposing you have a passing interest in keeping your house plants free of pests.
Where do house plant pests come from?
Realistically we can assume they come either on plants we’ve bought or in the soil of new plants.
However, if you create the right condition, they’ll just…show up. Especially fungus gnats, but that’s ok because apart from being annoying af, fungus gnats in normal quantities won’t really damage your plants.
In general, most plants prefer a moist environment and don’t like dry environments at all. So all of you overwaterers need to watch out – you’re actively encouraging pests to your plants.
Do check your plants when you buy them – especially if you buy plants from the reduced section. Often the rather sad, yellowing reduced plants have simply been overwatered, but always check.
Check orchids especially carefully. Orchids tend to be potted in bark, so the water can drain away pretty efficiently even if they’re watered every day.
Sad looking orchids may be infested (they could just be at the end of their flowering cycle but CHECK.
Check behind the flowers for mealybugs. I mention mealybugs specifically because they’re the pest I see most often in garden centres.
Types of house plant pests and how to identify them
Yeah, you’d think I was joking but I’m not. This is more specifically aimed at those of you that keep plants in terrariums. It’s not at all uncommon for slug eggs to wind up in the substrate or potting mix.
I know, because we have a fish tank that’s half water and half, er, empty, with a pile of mossy rocks that stick out of the water.
We added the moss and a watermelon peperomia that I’d been propagating. I was interested to see if it’d grow (it did).
A sunflower seed also ended up germinating in there (we assume it came from the birdseed we keep in a bin next to the tank). After the tiny baby slug ate the sunflower (which had grown beautifully – at time of death it had four leaves) an then moved onto the peperomia, whose since been moved to a safe house (a jar of water) and is going into witness protection.
The annoying thing is not only had I seen the slug, I’d taken a photo of it eating the sunflower and snet it to my boyfriend. By the time Dave messaged me back saying ‘GET IT OUT’ the little bastard had gone, NEVER TO BE SEEN AGAIN. We just noticed the plants decreasing in size and a lot of slime.
At the time of writing, he’s still at large in the fish tank.
How to identify slugs:
- they look like fuckin slugs
- Slimy af
How to get rid of slugs:
- Find it (harder than you’d think
- Chuck it outside (we’re not monsters)
- If you are a monster and want to kill it, take it to the nearest duck pond or similar and feed it to a duck. They love ’em. Slugs are toxic to most other animals, even hedgehogs that are falsely rumoured to eat loads of them, but ducks are hard and can handle them
I have a couple of plants with mealybugs. It was actually mealybugs that finally saw off my ill-fated Dieffenbacchia, but I can’t blame them – you wouldn’t blame a lion for putting a wounded gazelle out of its misery would you?
There was a severe case of mealybugs on the mahoosive cactus we’ve had for the past decade. The cactus doesn’t care. It’s currently massive and growing. It’s in a pot with no drainage holes and gets watered never. There’s gravel on top of the soil and the moisture probe proclaims the soil to be moist, despite me not having watered it all year.
Yes, I should repot it, but how?
It has spines an inch long! When we moved housed we had to wrap it in cardboard and use oven gloves, and the oven gloves made no difference. We were both severely spiked. It’s in an awkward corner of the kitchen an is just awkward in general.
It’s actually going to live at Dave’s work because it’s a fucking liability here. It’s sad because it’s old, but it’s basically the plant equivalent of a human with no brain function but being kept alive on life support – it’s basic functions are good but it has no quality of life.
I got rid of the mealybugs by using neem oil, but I think the infestation had actually gone before I got to it – there was just the gross white stuff left. I saw no actual bugs. Weird. Anyway.
How to identify mealybugs:
- They leave a white, cotton wool-like substance behind. I daren’t look up what that stuff actually is, because it’s probably something gross.
- The actual bugs look like little grey woodlice.
How to get rid of mealybugs:
- Dab the adults with surgical spirit. Although I don’t have any surgical spirit – mealybugs have barely any molecular integrity, so a gentle poke with a cotton bud kills ’em. It doesn’t make me feel like a very good vegan though. What am I meant to do though? Put up a sign warning all ye that enter here will get poked to death with a cotton bud? MEALYBUGS CAN’T READ.
- If the plant has a few big leaves, wipe them with neem oil (just dab a bit on an old rag or some kitchen roll. This disrupts their breeding cycle and does all kinds of things to their hormones that I don’t like.
- If the plant has lots of little finicky leaves, spray it with bug killer. I make up a mixture of 1tsp washing up liquid, a tbsp of white vingar and add it to a spray bottle of water.
The life cycle of a mealybug lasts a couple of weeks, so spray every four days or so for a fortnight to get rid of the bugs entirely. Although mealybugs are expert hiders, so keep an eye out for stragglers.
Never had ’em, never want ’em. Not to be confused with regular spiders, whom I encourage to make webs on my plants to reduce fungus gnats.
They tend to turn up when your soil is dry – they don’t like moisture at soil, so my damp house is probably the reason I’ve managed to avoid them so far.
If you exclusively bottom water your plants, it might be worth misting the top of your soil every so often, just to ensure spidermites don’t taken an interest
How to identify spider mites:
- They’re tiny red, er, mites.
- They spin webs, which is easier to see than the mites themselves
- You may see spots on the leaves, or even get a lot of leaf drop.
How to get rid of spider mites:
- Use other insects to eat them, ladybirds for example. Just go into the garden and get a couple. Be sure you have the correct insect – we don’t want a Simpsons-style scenario where you have to keep bringing in bigger and bigger predators until you’re overrun with gorillas. Apparently some people actually breed ladybirds, which sounds amazing. Definitely might try that next year.
- Spray neem oil on the plants – like with mealybugs, it disrupts the mite’s hormones and stops them from eating and reproducing.
- Insecticidal soap – the DIY bug spray I mentioned above will work too.
I currently have an aphid infestation on, embarrassingly enough, one of my carnivorous plants, but I keep tweezing off a load, and he seems to be dealing with the rest.
How to identify aphids:
- They’re small and green – the big ones are flies. And I’ve just read that the adult flies can be any colour. Well. Oh, and they don’t all have wings. We’re all learning today aren’t we?
- Apparently it’s common for ANTS to BRING aphids inside. WHY???
How to get rid of aphids:
- BUG SPRAY
- Not chemical ones though, because apparently aphids become immune super quickly.
- Wash your plants with soapy water – Dr. Bronner’s is a good one that won’t kill your plants.
- Neem oil. Obvs. I think a big takeaway from this post is that we all need some neem oil. It smells like peas and gravy.
Every palm I’ve ever had (admittedly only 2) have been killed by scale insects. I’m currently nursing another one, but I think winter will kill it off because it’s still very much recovering. Scale insects are awful, though kinda fun to pick off.
How to identify scale insects:
- Black dots on the base of the stem
- The adults literally look like scales on the plant.
How to get rid of scale insects:
- lf, like me, you’re a picker by nature, arm yourself with some tweezers and tweeze those suckers off.
- Surgical spirit/rubbing alcohol. I don’t think there’s much that wouldn’t work on, but try not to get it on your plant too much, because it can damage it.
- DIY bug spray.
- Neem oil
- Prune it. This can be the only option to dramatically reduce the number of bugs.
- Scrape the eggs of the stem
Ok, not a bug, and you can’t use insecticide on them (but you can spray them with water). If you’re seeing bite marks out of your plants, make sure it’s not your dog or cat before investing in bug killers. I’ve read that cats especially love African Violets, for reasons they’re yet to disclose.
I have a rabbit that is 100% likely to eat any of the house plants she can get her paws on, so we keep them apart. My mum’s dog likes to have a nibble on some of her plants, so they’re kept up a height. Don’t assume your pet will respect your plants.
Should you use chemical or homemade bug spray?
I do have a chemical bug killer, but I’m reticent to use it because all the research I’ve done would suggest that a) it can cause damage to your plants and b) bugs can become immune to it very quickly.
Also, for the price of a bit of vinegar and dish soap, isn’t it better to make your own? especially since you know it won’t damage your lungs or stain your carpet or whatever.
(I feel like I should tell you to be sure to spray your plants OUTSIDE because that’s what you should do, even though I don’t).
Tips for deterring and repelling pests
- Bottom water
Most pests like a damp environment in which to lay their eggs. Except for spider mites, which favour dry, hot conditions. Possibly why I’ve never had any problems with them.
Bottom watering allows you to control (kind of) how wet the surface of the soil becomes, by testing the moisture levels of the soil with a moisture probe. Once the water’s reached an inch below the surface of the soil, you can remove the water. Or the plant from the water. Whichever.
- Clean the leaves with neem oil
Not only does it give your plants a lovely shine, but it also stops insects from being able to breed on the plant. Neem oil doesn’t negatively affect most beneficial bugs except for bees. I’m assuming you don’t keep bees in your house so you’ll be fine, but be aware of this if you’re using neem oil outside.
- Diatomaceous earth
You can buy it on Amazon. Sprinkle a layer on top of your houseplants to stop the baby bugs from being able to get out of the soil.
Good grief, I went onto Pinterest to look up the uses of diatomaceous earth and people EAT IT. They EAT IT.
Ok, now I looked up what it actually is and it’s BABY PLANKTON.
Oh wait, they’re fossilised. I suppose that’s ok then.
It kills beneficial bugs too, so be aware of that if you’re going to use it – perhaps try grabbing a ladybird or two first.
- Beneficial nematodes
I know nothing about these, except that they’re basically good bugs that eat bad bugs. Betsy Begonia has a video that explains the process though – watch it here.
Keep a plant schedule
I don’t adhere to weekly watering schedule (and neither should you if you don’t want to kill your plants) but I like to check my plants over once a week to check for bugs, and what the new growth is like, and whether or not they look like they’re having a good time.
This is especially important at this time of the year and coming into winter, since pests can get a foot hold more easily. Winter growth is generally weaker and more susceptible to getting pests, and the plant can’t recover as quickly when it’s not growing.
If you do notice a couple of bugs, or even a full-scale infestation, the first thing to do is to move the plant into isolation.
(Unless, of course, you have a fiddle leaf fig, in which case you have to move all the other plants away to isolate it, for if you move a fiddle leaf fig it’ll have a massive hissy fit and drop down dead).
Physically remove as many of the bugs as you can using tweezers or a cotton bud. Mealybugs and scale especially love to get right into the crevice of the plants so be sure to check over thoroughly. If you’re unsure you can get them all, stick your plant into the shower and give it a gentle, tepid shower before spraying it with your bug spray.