Most people know every houseplant needs a certain amount of sun, water, and fertilizer to thrive. However, do you know what to do if you spot aphids on your leaves? Or why they show up there in the first place?
The number one reason you may have aphids on your houseplants is that they were looking for young plants to eat. They can get transported into your home on another plant, your clothing, or through your open window. You also may have already had an out-of-control infestation.
These aren’t the only reasons, however, and they don’t tell you much about how to prevent aphid infestations in the future. If you’d like to know more about why it’s important to treat your aphid problems (and how to do it), read on!
What Causes Aphids on My Houseplants?
We commonly think of aphids as an outdoor garden issue. Although, it’s not unusual to see these tiny green bugs crawling on tomato or cucumber leaves, leaving damaged, curled foliage behind and killing off your young seedlings.
How do aphids get inside your home to infest your precious houseplants in the first place? Here are seven reasons you might find them lingering on your monstera or crawling along your favorite ficus.
They’re Catching a Ride on Your Other Plants
Although it may be exciting to pick out a new plant from the nursery to bring home, it’s important to examine it before bringing it inside the house.
Look at the underside of leaves for any aphids clinging on and survey the plant for signs of the sticky sap aphids produce when they feast.
If you notice any signs of aphids, keep the plant somewhere they won’t be able to spread to your other houseplants or even to your outside gardens. If you spot an aphid, don’t worry! We’ve got all the tips on how to remove them in our guide below.
They’ve Already Infested Your Houseplants
Although you may think an infestation has just started, it may have been growing for quite a while, and you simply didn’t notice it!
Most people will only spot aphids when the infestation has gotten severe enough to cause visible cues like curling leaves or plants unable to grow and thrive.
That’s why it’s so important to spot-check your plants regularly, to stop aphids in their tracks before they can cause any damage to your beloved houseplants.
You’ve Used Too Much Nitrogen
Aphids love fertilizers with high levels of nitrogen and will reproduce quickly in the presence of one.
Although almost all fertilizers contain some nitrogen, varieties meant for producing large or copious amounts of fruits and veggies will contain high amounts of this substance.
For most houseplants, you can get by choosing a fertilizer meant for blooms and flowers, or even one meant for indoor plants specifically, like Miracle-Gro Indoor Plant Food
If it’s not the nitrogen, you may just be using certain flowers that aphids are attracted to.
They’re Eating Your Veggies
Although aphids don’t have any interest in mature vegetables, they are very interested in the seedlings you’ve started before the last frost. Aphids may have found their way inside your home, basement, garage, or wherever else you keep your new plants, to make a feast of them.
Once they’ve moved in, the aphids will reproduce and continue to feed, spreading to any other available houseplants nearby.
If you’d like to know which veggies are most prone to aphids, take a look at our guide on the 14 vegetables that aphids love!
They’ve Attached Themselves to Your Clothing
Aphids are industrious critters; not only will they grab onto any plants you may bring inside, but they’ll also cling to your clothing!
So, if you’ve been working outside in your garden (or even just come from an outside nursery or greenhouse), consider a change of clothes before touching any of your own houseplants.
This also means it’s possible to carry aphids on your clothing from friends’ homes or your neighbors’ yards if they have a severe enough infestation themselves.
They Came in Through an Open Window
Although a summer breeze feels great and is a nice way to air out a house after a long and stuffy winter, be warned aphids are light enough to be transported with the wind, right through your window and onto your favorite plants.
In fact, you might find one side of your outdoor garden is more infested than the other, as aphids land on the upwind side.
Once inside, any sort of airflow or breeze through your home can carry aphids from one end to another. This means it’s not enough to keep an infested plant in a separate room, as aphids can easily spread throughout your home through any open doors or sizeable gaps.
It’s Their Favorite Time of Year
According to the University of California Agriculture and Natural Resources Division, aphids cause the most damage in late spring (early summer) when temperatures are quite warm but not scolding (specifically, 65°-80°F.)
This means you may find more aphids during the spring, but it also means that once they’re inside your nicely temperature-controlled home, aphids may continue to wreak havoc until properly dealt with.
So what you should you do? Well, check your plants frequently during this time of year!
Paying particular attention to the underside of leaves, where aphids like to hide out the most. You may also want to keep an eye out for a sudden appearance of ants, which may indicate you have an aphid problem as well since ants feed on aphid byproducts.
Yes, Aphids Are Harmful To Houseplants
In a short answer, yes! Aphids can be very harmful to houseplants.
You don’t want even a few of these little creatures to make themselves at home, as they’ll quickly reproduce and spread among all your beloved plants.
Here are a few reasons in particular why it is best to prevent an infestation.
Aphids Can Cause Physical Damage to Plants
Aphids feed on plants (especially young, immature ones).
Unfortunately, this feeding process can really affect how well the plants grow.
t’s not unusual to see plants with curled, yellowed leaves, stunted growth, or even physical twisting or deformation of the entire plant itself after an aphid infestation.
They Leave Behind Sticky Honeydew
More specifically, aphids literally cause a sticky residue called honeydew to appear on your plants.
When aphids bite a plant, they inject saliva into it which in turn, helps digest the sweet sap from the plant.
So where does the honeydew come in? Well, it’s their byproduct.
This honeydew can coat plants, affecting their ability to take in sunlight, and giving them an overall sickly appearance.
Even worse, there are a few other pests that love to eat this honeydew, including ants and yellow jackets. It’s not unusual to find that with your aphid problem, comes an ant or other insect infestation not far behind.
Aphids absolutely love fruit trees due to their sweeter than normal sap. You can take a look at which fruits are prone to aphids here.
They Cause Sooty Mold Growth
Once you’ve got mold growth set in, you’ve got two problems on your hands: Taking care of the original aphid infestation, and stopping and treating mold growth, which can negatively affect and end your plants.
Unfortunately, these two problems combined may be a little more than your houseplant can handle.
The good news is the British Columbia Home and Garden Pest Management Guide reports you can remove most sooty mold by gently wiping with a little soap and water, restoring your plant’s ability to utilize sunlight.
The bad news? Unless you take care of your aphid issues, the mold will come right back again.
How To Get Rid Of Aphids On Indoor Plants
The good news is that even if you are dealing with an aphid infestation, you can quickly take care of them with only a few simple steps!
Here’s exactly how to stop your aphid infestation in its tracks.
Remove Aphids from Leaves
The first step is to remove any and all aphids you can see. The best method to do this is to pick each one off by hand, but if this feels a little too “ick” to you, you can also use a damp washcloth or paper towel to wipe them off.
You also may spray them with water from a hose or faucet sprayer.
Just be careful not to use too much water pressure, which may tear delicate leaves and stems.
Treat Houseplants with Extracts or Chemicals
Using organic or one of several chemical options, spray the underside of leaves thoroughly with a product meant for eliminating aphids.
If you have the space and means to do it safely, you can also dip the entire plant in solution to ensure you fully coat them in whatever substance you’re using to treat the problem.
Since some houseplants may be sensitive to certain types and concentrations of sprays, you should test the specific product on a few leaves of the plant, before using it on the whole of the plant.
If, after a day or so, the leaves do not show damage or any signs of wilting, you can use the spray with the confidence that it won’t harm your houseplant.
If you’d like to use a pre-made aphid control product, you can take a look at our guide on the best aphids repellents here!
Trap Wandering Aphids With Sticky Traps
Since aphids have several ways to move about and travel, it’s not enough just to deal with the infestation on the plant itself.
You’ll also want to trap any wayward aphids moving from one plant to another. Using traps such as these Gideal Yellow Sticky Traps can help you prevent reinfestation of plants you’ve already treated or an invasion of a new plant.
Mainly, sticky traps are for detection and early control to give you a bit of time to solve the problem permanently.
How To Prevent Aphids On Houseplants In The First Place
Successfully preventing an aphid infestation requires keeping a keen eye out for the longevity of your plants, as well as taking a few key steps to stop aphids from making their way inside your home.
Here are our top methods for preventing future invasions:
If you have aphids continually coming back, I highly recommend checking out our guide on the most common reasons WHY they keep coming back.
Check Your Houseplants Frequently
Particularly during your specific region’s growing season, you’ll want to check over all your houseplants every few days.
Aphids move quickly and waste no time in eating plants, spreading issues and damage to your precious green friends.
Left unchecked, they can quickly reproduce and spread from one houseplant to another, turning your minor problem into a big one fast.
If you check over your plants frequently, you’ll be able to spot the first few aphids before they cause damage or reproduce.
Isolate Any Houseplants with Infestations
If you spot an infested plant, quickly sequester it in a location far from your other plants, preferably with a closed door between the two.
Also, consider keeping any vegetable seedlings for your garden completely separate from any houseplants, as aphids will be particularly interested in feeding on these types of sprouts.
Set up some indoor grow lights in the garage, closet, or other areas that can be closed off from any of your mature indoor houseplants.
Use Sprays and Oils as a Preventative Measure
Any of the above-listed sprays are a safe and effective option for taking care of aphids.
If you do not have an active infestation, applying the sprays occasionally during the growing season or late spring (combined with the other listed techniques) can be enough to stop an aphid invasion before it starts.
If you’d like to use natural repellents to keep aphids away, take a look at our piece on the scents that aphids hate here!
Use Low Nitrogen Fertilizers for Your Plants
Avoid fertilizers meant for vegetable gardens in favor of mixtures designed for flowers like this Fox Farm Big Bloom Liquid Concentrate Fertilizer.
They contain lower amounts of nitrogen, which will help discourage aphids from reproducing quickly!
Place Screens Over Open Windows
Even if you use other methods to take care of aphids, you’ll still need to prevent them from sneaking into your house in the first place!
That’s why it’s best to make sure that all your windows are properly screened. This can also help ensure you safeguard your home against other creepy crawlies that may try to sneak inside.
Change Your Clothes After Working Outside
If you see evidence of aphids in your outside garden, it’s best to change your outer layer soon after coming inside, and avoid touching any houseplants before you do.
This is because aphids can hitch a ride on your jacket, pants, or shirt, and cause an infestation inside, even if you’ve been taking other preventative steps.
It’s much easier to prevent an aphid problem than it is to treat one!
Use Aphid Traps in Your Home
As a last line of defense, consider putting out sticky traps near open windows, doorways, and wherever you have a large concentration of house plants.
If aphids get inside your home, having these traps can mean the difference between containing the infestation to one plant, or having to treat a widespread invasion across all your plants.
The more measures you can take to prevent an infestation, the less work you’ll need to do daily to remove aphids and treat your plants.
That’s a Wrap!
Although an aphid infestation can be a pesky hassle to deal with, causing damage to both indoor and outdoor plants, you can successfully stop and prevent future aphid problems with a bit of knowledge and foresight.
First, you’ll want to look out for signs of aphids, like little green bugs clinging to the underside of leaves, yellowed and curled foliage, or plants that fail to thrive.
Second, know the steps to treat aphid infestations. Remove any bugs you find, use sprays designed to take care of aphids, and make sure you place screens on your windows and inspect any new plants to prevent future aphids from spreading throughout your home.
If you find you are still having issues or questions, don’t hesitate to contact a professional to take care of your issues. With our Pest Pro tool, you can quickly and easily find someone local to help you with any pest problem, big or small.
Ambid, Ma Caselyn, and Niña A. Bautista. “The Effectiveness of Garlic and Hot Chili Pepper in Getting Rid of Harmful insects.” Ascendens Asia Journal of Multidisciplinary Research Abstracts 3.2I (2019).
Darriet, Frédéric. “Laboratory study of an innovative concept to control aphid pests and mosquito vectors of pathogens to humans.” Pest Management Science 78.3 (2022): 1071-1080.
Iqbal, M. F., et al. “Effectiveness of some botanical extracts on wheat aphids.” The Journal of Animal & Plant Sciences 21.1 (2011): 114-115.
Laemmlen, Franklin F., and James Kenneth Liebherr. House Plants: Common Insects and Diseases. Cooperative Extension Service, Michigan State University, 1976.