Sometimes it feels like all of the plant bugs on the planet are trying to attack my houseplants! Until last winter, I’ve never had to deal with houseplant scale before. I have no idea where they came from, but one day I suddenly noticed that my goldfish plant was infested with scales. Gross! But don’t worry, scale is not a death sentence for your plants! I’ve successfully descaled my houseplants, and so can you!
Scale insects are very difficult to see on a plant. Even if you do notice them, scales 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!
What Is Houseplant Scale?
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, and leaf drop. The damage caused by scale insects is not as quick to occur or as devastating as it is with spider mites. If a houseplant scale infestation goes left untreated, the plant will eventually die; although it would take a long time for scale to kill a large houseplant.
Houseplant Scale
Identifying Houseplant Scale
You will usually find houseplant scales hanging out on the stems and leaf joint of an infested houseplant. Scale insects can be rounded, oval shaped or flat, and can range in size from barely visible to large bumps on a plant. They 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 the plant has become infested. Disgusting!
Related Post: How to Control Soil Gnats
Neem Oil To Control Houseplant Scale
How To Control Houseplant Scale
Houseplant scale control is similar to mealybugs. As with any plant pest, when you find scales on houseplants, isolate the infested houseplant and begin treatment immediately. I don’t recommend using pesticides, because houseplant scale are resistant to most pesticides. They also have the ability to develop a resistance to any pesticides they are exposed to on a regular basis. So keep your family and pets safe, and skip the toxic pesticides on your houseplants. Try these all natural pest control methods instead…
- Kill and remove as many of the houseplant scale insects from the plant as you can 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.
- Neem oil is very effective to control houseplant scale infestations, and it has a residual effect to help with future pest prevention. You can buy neem oil for pretty cheap, and a big bottle will last a long time. Trust me, it’s well worth the price! A pre-mixed horticultural oil or hot pepper wax spray also work very well when used directly on scale insects.
Rubbing Alcohol Kills Houseplant Scale
- As you treat a houseplant, make sure to inspect underneath all the leaves, around the leaf joints, in folds and at the base of the plant for houseplant scale. They like to hide so check the plant from several angles and under each leaf. Also brush away a little dirt and check the base of the stem at the point where it sticks out of the dirt, scale insects could also be found on the roots of the plant.
- Use an insecticidal soap or a solution of soapy water to spray directly on the scale and on the leaves of your infested plant (I use 1 tsp of Dr. Bronner’s Baby-mild Liquid Soap per 1 liter of water). If the plant is small enough, bring it to the sink or shower and wash the leaves with this soap and water solution, gently removing as many of the scales as you can as you wash the houseplant. Keep in mind that soap can damage the plant, so it’s best to test it on a few leaves before spraying the entire plant.
Soapy Water Kills Houseplant Scale
- Houseplant scale can live 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.
- 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 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). Don’t trim all the leaves from a houseplant though.
It’s hard to get rid of all of the scales 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. Fighting houseplant scale can be super frustrating, but it’s worth it to save your favorite houseplants.
More Information About Houseplant Pest Control
- Organic Plant Pest Control Supplies
- Neem Oil as Organic Pest Control
- How To Control Houseplant Pests
- Where Do Houseplant Pests Come From?
- Debugging and Cleaning Potted Plants
Organic Pest Control Products I Recommend
For more houseplant pest control tips and information, click here… Houseplant Pests
Have you ever had to fight houseplant scale? Share your tips in the comments section below.
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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.
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
what amount of houseplant insect control to use for a 19′ pot dont see any description
I’m not sure how much that would take for a large pot. One spray bottle full lasts for several 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.
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.
Hi Mary,
So sorry to hear about your fern! I hate when that happens! Those pesky 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 alway 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!
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
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! 🙁