How to identify and treat an aphid infestation on your houseplants, plus tips for bringing a plant back to health

• Aphids are tiny insects that suck the sap from a houseplant's leaves.
• Neem oil and diatomaceous earth are the best organic solutions to use to rid plants of aphids.

As warmer weather and fertilizer season approaches, keeping houseplants pest-free may feel like an overwhelming or unpreventable task. And aphids, known as the vampires of the pest world, are no exception. They have sap-sucking abilities that ultimately weaken an otherwise healthy houseplant.

Author and plant expert Linda Ly of Garden Betty shares her best tips on how to get rid of aphids and keep them from invading your houseplants any time of the year.

How to identify aphids

Aphids are soft-bodied, sap-sucking insects of the family Aphididae which feed on a plant's nutrient-rich sap. They are pear-shaped with long antennae and are usually bright lime green in color, but can sometimes come in black, brown, pink, or yellow.

A single aphid can be difficult to identify with the naked eye because of their tiny size, but they become more visible on a houseplant when they are clustered together.

To know if your houseplant has aphids, Ly explains that certain ailments and methods of overcaring can be good indicators of pests.

"Aphids are attracted to new, lush green growth, so overfertilized houseplants are their favorite host plants," she says. "They also tend to attack plants whose defenses are down, which means underwatered, overwatered, or otherwise stressed plants due to light, temperature, and/or transplant shock can also become targets."

Once aphids have weakened a houseplant, the plant will usually show signs of curling, yellowing, or misshapen leaves. Other symptoms include deformed flowers or fruits if your plant produces them.

"Aphids often go unnoticed since they like to hide and lay eggs on the undersides of leaves, but the first signs of an aphid infestation are curled leaves that eventually wither up and die," says Ly.

Ly explains that aphids leave behind a sticky substance called "honeydew" as they feed on plant sap, which attracts ants. If you see a trail of ants suddenly invading your houseplants, this may be a sign that aphids are nearby.

How to get rid of aphids on houseplants

Once aphids' reproduction rate and multiplication begin, it can be difficult to get an infestation under control. The good news, however, is that their growth rate can be slow, so with early detection and proper care, your plant can keep thriving.

With each method, it is important to monitor your plant daily to see if the infestation has been reduced or fully controlled. Keeping infected plants away from healthy plants is also imperative to avoiding a spread. If your plant ceases to drop leaves and/or if you no longer see any aphids, individuals or clusters, then your aphid removal method has worked.

Remove leaves

Ly explains that if aphids are caught early, meaning only a few are visible and have not clustered, an infestation can be managed by removing the infected leaves. While this can also mean cutting off some stems, this step may be necessary if the aphids have started to cluster or if organic methods of removal, such as neem oil, do not work.

Homemade neem oil spray

Neem oil is one of the best organic methods of getting rid of pests. To create your own neem oil spray, mix 1 to 2 tablespoons of neem oil with 1 to 2 tablespoons of mild dish soap and a gallon of warm water, then transfer to a spray bottle. Shake the bottle thoroughly and lightly spray on plants once a week during the early mornings or evenings to avoid direct sunlight. Using protective gloves, gently rub the mixture on the leaves and stems.

Diatomaceous earth

Another organic method to get rid of aphids is food-grade diatomaceous earth. This white powder is made from the fossilized remains of small aquatic plants and organisms. Ly prefers this method for its easy application and effectiveness.

Before application, thoroughly water the leaves of your plant, gently hosing them in the shower, kitchen sink, or backyard to avoid damage to delicate plants. This is to wash away some aphids and allow for the diatomaceous earth to stick. Try watering the plant turned on its side to avoid overwatering the soil.

Next, sprinkle the substance on the leaves and dirt, attempting to cover as much of the plant as possible. Use a clean makeup brush to apply the powder on the smaller or harder-to-reach areas of the plant. Repeat this process every two to three days for about a week. If the infestation has been controlled, your plant can return to its normal care and maintenance.

Chemical insecticide

When it comes to getting rid of pests from houseplants, organic methods are the best way to avoid damaging a plant, especially weak ones, and harming protecting pollinators. With particularly severe infestations, however, chemical insecticides might be the last or only resort to get rid of pests.

Ly recommends insecticidal soap since it is fast-acting, effective, and can kill almost any plant pest. Follow the instructions on the bottle, or spray the entire plant including the undersides of leaves a couple times per week in the early mornings or evenings to avoid direct sunlight.

Quick tip: Both neem oil and food-grade diatomaceous earth are organic and non-toxic to both cats and dogs. Chemical insecticides, however, can be dangerous for pets if ingested.

How to save a plant with aphid damage

Unlike other severe diseases or ailments such as root rot, a houseplant can easily be saved from aphids with just some extra attention and an effective removal method.

If aphids have already affected your plant enough to turn leaves yellow and curled, it's best to cut off these sections, along with any other infected leaves or stems, with disinfected pruning shears. Supplementing this removal with neem oil or diatomaceous earth can give your plant the best chance at returning to its original state.

How to prevent aphids from coming back

Aphids are attracted to overfertilized, overwatered, and underwatered plants, so maintaining proper and consistent houseplant care is key in preventing aphids. Soft, limp leaves and soggy soil usually signify overwatering, while dry, crispy leaves and more than an inch of dry soil signify underwatering. Avoiding stress on houseplants — whether it's from moving them around too much, leaving them in drafty areas, or over-fertilization — is the best rule of thumb to go by.

"Aphids are attracted to weakened plants, so keeping yours healthy and thriving is key to keeping aphids in check," says Ly.

Insider's takeaway

By making sure your houseplant stays healthy through proper watering and the right level of fertilization, future aphid infestations can be easily avoided. With natural insecticides such as neem oil or diatomaceous earth, removing infected leaves, or a thorough yet gentle leaf watering, getting rid of aphids can be a simple process to restore your houseplant's lushness and health.