When you find scale on plants, getting rid of them can take some time – but it’s not impossible! In this post, I will show you exactly how to get rid of scale on houseplants, FOR GOOD. Simply follow these organic houseplant scale treatment methods.
Sometimes it feels like all of the plant bugs on the planet are trying to attack my houseplants! Until a few years ago, I’ve never had to deal with houseplant scale before.
I have no idea where they came from, but one day I suddenly noticed a scale insect infestation on my goldfish plant. Gross!
But don’t worry, scale is not a death sentence for your plants! I’ve successfully descaled my houseplants, and so can you!
What Are Scale Insects?
Houseplant scale are gross looking things that suck the sap out of the leaves and stems of plants; resulting in stunted or deformed leaf growth, yellowing of the leaves, brown pock marks, and possibly leaf drop.
You will usually find houseplant scale hanging out on the stems and leaf joint of an infested houseplant, and along the veins of the leaves, but you could find them anywhere on a plant.
You may also notice sticky leaves on houseplants, on their pots, or around the area where the plant is sitting. Sometimes this is one way to help with plant scale identification if you’re unsure. As they feed, scale insects excrete a sticky residue which is a common sign of an infestation.
What Does Scale Look Like On Plants?
Scale insects are very difficult to see on a plant. Even if you do notice them, scale bugs on houseplants look more like a weird growth than a bug.
They look like small brown dots or bumps, and they don’t move. Eek! To me, they look like scabs on a plant (and that’s seriously what I thought they were the first time I saw them, haha!).
They can be rounded, oval shaped or flat, and can range in size from barely visible to large bumps on a plant. Their color can range anywhere from brown to tan to white. (If the bugs on your houseplants are white and fuzzy and look more like mildew, then those are mealybugs. Here’s how to get rid of mealybugs.)
Scale bugs on plants like to cluster, so they are very noticeable once the population gets large. Like I said before, they don’t look like bugs so you probably won’t even notice them until your plant has become infested.
Different stages of scale insect life cycle
Houseplant Scale Insect Life Cycle
There are several stages to the scale insect life cycle, and the entire cycle takes about 7-10 weeks. It takes a few weeks for the eggs to hatch into nymphs (aka scale crawlers), and then another 6-9 weeks for the crawlers to mature into adults.
A scale crawler can move around on a plant (or migrate to surrounding plants!) and, once they find a good place to start feeding and mature into adults, they never move again.
Scale insect eggs and nymphs are tiny, so it’s easy to understand why most people will never know their houseplant has scale until the population has exploded.
Scale Damage On Plants
Scale insect damage can look like pock marks on plants like succulents and cacti, or it can be something as subtle as brown or yellow leaves on a plant.
Thankfully, the damage caused by scale insects is not as quick to occur or as devastating as it is with spider mites, but it can still look pretty bad.
If a houseplant scale infestation goes left untreated, the plant will eventually die; although it would take a long time, and a very large scale population for them to kill a large houseplant.
Related Post: How to Get Rid of Fungus Gnats In Houseplants Soil
Scale insect damage on cactus plant
Where Do Scale Bugs Come From?
When you discover scale on plant leaves, the first question you’ll ask is where the heck did they come from? Scale insects are very sneaky, and many times you will never figure out where they came from.
Indoor plant bugs can come from anywhere, so don’t go crazy trying to figure it out what causes scale on plants. But, here are a few of the most common places where they may have come from…
- A brand new houseplant that you recently brought home from the store
- Contaminated potting soil
- Reusing a dirty plant pot
- Moving your houseplants outside during the summer
- Fresh produce or cut flowers from the garden (or even from the grocery store!)
- An open window – the crawlers are tiny, so you never know!
Read more about Where Do Houseplant Pests Come From?
Houseplant scale and damage on my cactus plant
How To Get Rid Of Scale Insects On Houseplants
As with any plant pest infestation, when you find scale insects on plants, you will want to isolate the infested plant and begin treatment immediately.
I don’t recommend using a chemical scale pesticide, because houseplant scale are resistant to most pesticides. They also have the ability to develop a resistance to any chemical pesticides they are exposed to on a regular basis. Plus, in most stages of their life cycle, pesticides won’t penetrate their hard outer shell anyway.
So keep your family and pets safe, and skip the toxic chemical pesticides on your houseplants. Use these all natural pest control methods instead…
How To Treat Scale On Plants
One way to kill and remove as many of the houseplant scale insects from the plant as you can is by using a cotton swab dipped in rubbing alcohol (you may need to pry some of them off using your fingernail). In order for rubbing alcohol to be effective, it must come in direct contact with the scale insects.
This scale bug treatment method works very well for small infestations, and to get rid of as many of the large scale insects that you can so you can gain the upper hand.
As you work on removing scale from plants, be sure that you check every crevice of the plant, around the leaf and stem joints, and underneath all of the leaves. They like to hide, so be sure to check the plant from a bunch of different angles too.
Also brush away a little dirt around the base of the stem to see if any are hiding there, scale insects could also be found on the roots of the plant.
Use rubbing alcohol to kill scale on houseplant
Make Your Own Homemade Scale Insecticide Soap
You could buy organic insecticidal soap, or you can make your own homemade insecticide for houseplants. The plant scale spray recipe I use 1 tsp of organic mild liquid soap per 1 liter of water. Then spray it directly on the scale and on the leaves of your infested plant.
If your plant is small, you can bring it to the sink or shower and wash the leaves with this soap and water solution, gently removing as many of the scale as you can as you wash the plant.
Keep in mind that some types of soap can damage plants, so it’s best to test any type of spray on a couple leaves before you spray the entire plant.
Homemade scale insect killer insecticide soap
Using Neem Oil For Scale On Plants
Neem oil for houseplants is a natural insecticide for indoor plants, and it’s very effective for treating scale on houseplants. An added bonus is that neem oil has a residual effect to help with future pest prevention too.
You can buy neem oil concentrate for pretty cheap, and a bottle will last you a long time. If you do end up getting the neem oil concentrate, then you’ll need to mix it with a little bit of mild liquid soap to help the oil mix with water. Don’t worry, it’s easy, just follow the instructions on the label.
You can use a pre-mixed horticultural oil or hot pepper wax spray instead of neem oil as a plant scale treatment, and these also work very well to help get rid of scale insects.
Learn more about neem oil insecticide
Using neem oil insecticide for scale insects
More Tips For Getting Rid Of Scale On Plants
You can’t treat a plant once and expect to get rid of scale insects for good, you need to be persistent. Keep checking your plants a few times a week, and remove any new bugs that you see. Here are a few additional tips…
- Scale can hide in the soil of a houseplant, so if a plant is plagued by recurring infestations, you could try removing the top inch of dirt from the pot and replacing it with fresh potting soil.
- Crawlers can leave the plant, and then come back to infest it again. So remove the plant from the area and clean any crevices where plant pests could be hiding. Be sure check around the outside lip and inside edges of the pot and plant tray, and also the bottom of the pot for hiding scale insects.
- Trim any heavily infested leaves from the plant and toss them into the trash (outside of your home). Never trim all the leaves from a houseplant though.
- If you decide to repot a plant after treating it for scale, then be sure to sterilize the pot before reusing. Houseplant scale insects can hide on the edges or the rim on a plant pot, and can easily infest any plant that’s potted in there. Scrub the pot with soapy water, or better yet, put it in the dishwasher to sterilize it.
- Use a neem based leaf shine, a natural insecticide for houseplants, regularly until you are sure you plant is scale-free.
It’s hard to get rid of scale on houseplants the first few times you try, it will take several treatments. Even if you are able to kill all of the adults, the eggs and babies are tiny and easily overlooked.
There’s no doubt that fighting scale on indoor plants can be super frustrating, but it’s worth it to save your favorite houseplants.
If you’re struggling to get rid of bugs on indoor plants, my Houseplant Pest Control eBook is for you! It will show you exactly how to get rid of bugs on houseplants naturally, including houseplant pests identification, home remedies for plant insects, how to keep houseplant pests from EVER coming back, and much more! Download your copy today!
Organic Pest Control Products I Recommend
Recommended Reading:
More Information About Houseplant Pest Control
- Organic Plant Pest Control Supplies
- How To Debug Plants Before Bringing Them Indoors
- How To Get Rid Of Spider Mites On Houseplants, For Good!
- How To Get Rid Of Whiteflies On Indoor Plants, For Good!
How do you get rid of scale on houseplants? Share your scale insects treatment tips in the comments below.
Tom says
Scale is a huge problem for our plants. My wife sometimes just wants to chuck them because we have 2 small kids, 2 dachshunds and a cat. And we don’t want to use any pesicides because obviously that’s bad for all of us. Did not know that Bronners baby soap could be used. Will try.
Amy Andrychowicz says
Yes, you definitely don’t want to be using toxic pesticides! Along with the Bronners soap, Neem oil works great on houseplant scale too. Good luck!
Amy
Barbara Shellko says
what amount of houseplant insect control to use for a 19′ pot dont see any description
Amy Andrychowicz says
I’m not sure how much that would take for to treat scale on a large pot. One spray bottle full lasts for several scale treatments. You don’t need to spray the plant until the leaves are dripping wet, but make sure you get an even spray on all the leaves.
Mary says
HI Amy,
I have a large, VERY handsome kangaroo paw fern (which I dearly love) that I recently noticed a few scales on. It’s a dense and complex plant. (I have to use a small tube to get water thru to the soil!) My plant shop recommended a mineral oil based organic spray treatment (Summit), which I’ve applied once now. It’s a big operation getting all his leaves all over! I’ve been reading about neem oil treatment, and wondering if that would be better. ???
ALSO, since it’s so hard to get thru to the soil, could I actually WATER the plant with the neem oil solution to get to the soil and upper stems/roots?
And one more: Is the neem oil sol’n safe to spray on the little delicate new fronds?
Many thanks! I’m heartbroken over this, and have no idea how it happened.
Amy Andrychowicz says
Hi Mary,
So sorry to hear you found scale on your fern! I hate when that happens! Those pesky scale bugs can come from anywhere, you’ll probably never know for sure. I have never used a mineral based organic spray before, so I can’t speak to that. Neem oil has worked for me against scale, so I know that would work – just not sure if it would be better than what you’re already using. I always recommend that people test any type of spray on a leaf or two before spraying the whole plant. Let it sit for a few days, and if there’s no signs of damage, then it should be safe to treat the whole plant. Good luck to you, hope you get rid of those suckers!
Judy Prokosch says
I had 2 Swedish Ivy magnificent plants for years. Early spring and into summer I noticed they began to throw what I thought was plant sap. It was sticky all over the leaves and on the window ledge. It wiped up easily. I phoned a local greenhouse and explained it seemed to start after I had spilled some Coca Cola on the leaves. The staff thought the sugar might have started an organism in the soil to become active. When I insisted my son the green thumb take a look he was startled and found quite an infestation of scale under the leaves. Is this stickiness a common manifestation of scale?
Our house plants have always been so healthy but now I know what to look for. And I say had above because the largest plant was pretty well covered. We decided to discard both plants. I look forward to your response about the stickiness. Thank you. Judy
Amy Andrychowicz says
Yes, the stickiness is indeed caused by the scale insects feeding on your houseplants. As scale feed on plants, they secrete a sticky honeydew residue. I don’t think that spilling cola on your plant had anything to do with the scale infestation. I suspect the plants were infested with scale long before the soda incident, and spilling the soda on your plant just made you more aware of what was happening with your plants. Houseplant scale isn’t easy to see from far away, and many times will go completely unnoticed until the plant is completely infested (as yours were). Sorry for your loss of two beautiful plants! 🙁
Barbara says
! discovered that the coffee table was sticky, sure enough, scale all over my gorgeous goldfish plant. I removed quite a bit of scale with my fingernails, but the plant is dense with leaves, so I resorted to sudsing it with Dawn soapsuds, gently rubbing both sides off the leaves.
Now, two days later, leave are falling off by the handful!! I took it outside and showered it off, then left it out to dry (away from other plants.) Leaves continue to fall, leaving many bare stems. So sad! Is there hope? Anything else I can do? I did find it to be very dry. (It has recently been quite sunny, but nothing this plant isn’t use to (morning sun). I watered it good today.
Amy Andrychowicz says
Oh no, I’m so sorry to hear that your goldfish plant is infested with scale! That is so frustrating. Unfortunately, soaps like Dawn have chemicals and degreasers in them that can be very damaging to plants. If you’re ok with leaving your plant outside all summer, I would find a part shade spot for it, (keep it out of the full sun though), and leave it there to recover. Just keep it watered like you normally do, and hope for the best. Once it starts to grow healthy new leaves, then I would spot-treat any scale insects you see. Once your plant has recovered, try the neem oil treatment before bringing it back inside. As long as that doesn’t damage your plant, I would treat the plant with neem oil until you no longer see signs of scale. Then keep a close eye on it after that for signs of re-infestation. Be sure to clean the coffee table and surrounding area really good before putting your plant back in it’s spot. In the future, it’s best to test any sprays you use (on any of your plants) on a few leaves before spraying the whole plant. Even commercial plant sprays can damage sensitive plants. Good luck!
Ashley says
Hi there! Fellow Minnesotan and I loved the article. I have a nasty infestation I’ve been working at for 2 years on 2 Philodendrons. Do you have any recommendation of how much pure neem liquid concentrate to use? I’ve picked some up at a coop and would like to mix it in a spray bottle but don’t know ratios. Thanks!
Amy Andrychowicz says
Hello from MN! 🙂 Sorry to hear about the scale insects on your philodendrons, that’s a bummer! If there aren’t any instructions on the label of the neem oil concentrate that you bought, you can find my neem oil spray recipe and detailed instructions on how to use it here… How to use neem oil insecticide
Sharon peterson says
Greetings from Arizona. A few weeks ago I noticed my rose Bush was looking shabby. Some kind of incect had been eating the leaves. Further investigating, I found hairy creatures on my plant. Got my sheers to cut off some leaves that were infested. When my arm touched the leaves I received a very nasty burning sensation to my skin. Did some research on google and found out they were from the cotton scale family. Was told to use dawn dish detergent on my plant. Curious if they can cause a skin reaction which feels like your skin is burning. Went to the doctors and was told to take allergy meds and hydrocortisone cream. My first time dealing with this issue. Any professional advice would be appreciated. Thanks…..
Amy Andrychowicz says
I’v never heard of scale insects causing any kind of skin irritation. You describe the pests on your plant as hairy, which doesn’t sound like the houseplant scale that I describe in this post. Were they mealybugs (those don’t sting, bite or cause any type of skin irritation either though)? I know there are certain types of hairy caterpillars that eat plants and can sting, did the bugs on your plant look like caterpillars?
Sarah says
Hi Amy. Thank you for the informative article. I’m about to get your book.
I got scale on some of my houseplants (cacti and succulents). Unfortunately one of my cactuses got it. After I had removed all the scale, cut off infested parts, and isolated the plant to monitor it, I realized that, somehow, my other plants got scale too.
I am going to cut off all the heavily infested parts of my plants. Quite frankly, I am having a difficult time identifying whether what I’m seeing on my plants is scale or normal. So I am hesitant to go about the scrubbing scale off method.
I’m wondering, if I go through the following process, will it be successful in killing the scale *IF* I don’t elect to remove the adults? AKA will using rubbing alcohol, horticultural oil, and Azamax — with their advised dosage of course — be able to kill the adult scale and prevent the nymph scale from setting up shop? I just don’t want to spend the time removing all the scale from my plants. It is too time-consuming for me unfortunately, as I have too many plants!
Process: (a) spraying my plants down with rubbing alcohol (b) spraying them down with horticultural oil and Azamax (c) throwing out all the soil in my plants and washing as much soil as I can from their roots (d) sterilizing all my plants’ pots (e) repotting with new soil (f) drenching the newly-potted plant with Azamax (g) repeating a, b, and f at least two more times if new scale are noticed.
Amy Andrychowicz says
My guess is that, since those bumps were never on the plants before, and suddenly several of your plants have it, then indeed it is a houseplant scale infestation rather than normal growth on the plant. I have never used Azamax before, so I can’t vouch for that. But it looks like it contains neem oil, so it should work. I would not repot the plants. Such a severe pest infestation puts a lot of stress on plants. The shock of repotting them might be too much for them, and you may lose a few plants. You could remove the top inch of soil, and clean the rim and edges of the pot really good and check the base of the stems rather than repotting them. Be sure to also disinfect the entire outside of the pots, including the bottoms and any plant trays. Also clean the entire area where the plants are sitting.
I would recommend doing the neem oil treatment for much longer than just two or three times. With an infestation that large, it will probably take a few months for the neem oil to work to get rid of all of the bugs. I also recommend testing the rubbing alcohol and any sprays on a few leaves of your plants first before treating the entire plant. Some plants are very sensitive to sprays and can be damaged or killed.