Photo by William Fountain/University of Kentucky/Bugwood.org An example of Mealybugs on a leaf

A houseplant’s demise can sometimes be mistaken for owner neglect, but lack of care may be a misdiagnosis. Infestations from the most common houseplant pests, such as spider mites, scale, mealybugs and fungus gnats, can sometimes be the culprits. Fortunately, there are many ways to prevent and treat an infestation. With patience and persistence, most houseplants can be fully rehabilitated.

Photos by William Fountain/University of Kentucky; Joseph LaForest/University of Georgia/Bugwood.org
Mealybugs produce like rabbits in the insect world

What to look for 

The first step is to know what you are looking for. Before bringing out your magnifying glass, some easy-to-identify signs that you might have a pest problem include small silky webs, little round white crust-looking spots on the underside of a leaf, gnats flying close to the soil or tiny specs that look like cotton fibers. If you know you are properly caring for your plants, but leaves turn yellow or plant edges crinkle and fall off, you may have a pest problem. Identifying and treating the four most common pests that plague houseplants will save them from becoming compost.

According to Clemson’s College of Agriculture, spider mites are actually related to spiders, not insects. Their eggs are translucent to light yellow in color and can usually be spotted nestled in a silky web. More mature mites appear as brown dots on leaves. Discolored areas on leaves could be spots where a mite has sucked out sap. 

Scale is an insect that lives most of its life on the woody stems and undersides of leaves. They live up to their namesake by looking like a brown-ish raised scale. Their armor-like exterior protects them from predators as they use their spiky mouth to remove nutrients from plants. 

Mealybugs are insects that appear to be surrounded by cotton fuzz. They move slowly often hiding in hard-to-see places. Most plant parents dread mealybugs — because they are difficult to control. According to Homestead Brooklyn, mealybugs reproduce like rabbits in the insect world. Females can lay about 600 eggs at one time, and in seven to 10 days, you can have an infestation. Another month or two later, those babies turn into full-grown adults and the cycle restarts. Despite being voracious reproducers, their mobility easily allows them to move from plant to plant. 

If you see tiny flies zipping above the surface of the soil of your houseplant, you likely have fungus gnats. They aren’t sucking the sap out of the leaves like spider mites, mealybugs or scale; instead, they’re either eating tiny root hairs or soil nutrients, killing your plant from the bottom up.

Chazz Hesselein/Alabama Cooperative Extension System/Bugwood.org
Yellowing leaves or crinkling plant edges might signify a pest problem.

Locals recommend treatment options

There are chemical and non-chemical options for treating these common pests. B.J. Stadleman, owner of Haegur plant shop on King Street, creates his own non toxic concoction made of Dr. Bronner’s castile soap and water. Preferring peppermint scent because it has the added benefit of repelling most pests, he uses ½ teaspoon of the soap to 16 ounces of warm water in an amber-colored spray bottle. Stadleman recommends taking the plant outside and giving it a good spray to ensure the mixture reaches all of the insects. Once it dries, carefully hose down the plant. Repeat, if necessary. 

For fungus gnats, Kendal Leonard of Meeting Green garden center, also in Charleston, has a three-pronged approach. Treatment includes spraying neem oil once a week at the soil level then letting the soil dry out. Gnats need water to reproduce, so letting the soil dry out interrupts their life cycle. If that doesn’t do the trick, she recommends sealing the pot using plastic bags to suffocate the gnats. 

Even when purchasing a new plant for herself, Jesse Nersesian, owner of Plant Babe located nearby, is not scared off by a little insect infestation. But she likes to know what she’s dealing with, adding “having plants and coming across bugs go hand in hand.” Her go-to fix is Bonide’s Systemic Houseplant Insect control for prevention or wiping diluted rubbing alcohol all over the plant and putting it in the shade. 

Amy Gangi of Leaf Me Alone Plant Club in Park Circle prefers a mix of neem oil and water. The mixture is a “safe, organic insecticide that you can use around kids and pets; perfect for indoor plants,” she said. 

At Roadside Blooms, we like to use a cotton swab with either neem oil or a soap mixture to physically remove pests after they’ve been sprayed or hosed down. Some of these pests are pretty tenacious, especially scale, and ensuring the treatment gets under their armor sometimes requires a little elbow grease.

Prevention is key 

Before purchasing a new plant, it is imperative that you carefully inspect the plant for pests. Plant shops inspect frequently as no one wants an infestation in their inventory, but sometimes the insects can evade even the most careful observer, especially when plants are immature. Before placing your new plant into your home collection, quarantine it for a few weeks just in case anything hatches. This simply means placing it away from your other plants but still in a spot suitable to meet the plant’s needs. If possible, when styling your plants, be sure to place your plants so that leaves don’t touch. This will help prevent things like spider mites or mealybugs making their way to your neighboring plant friends. 

Houseplants under stress from lack of proper care are more vulnerable to infestations. Taking good care of your plants so that they are healthy will help them to survive should pests take over. 

If you do spot an infestation in one of your houseplants, be sure to quarantine this plant immediately, then inspect your other plants right away. Treat the infected plant. Return it to its former spot only after it appears the infestation is gone, which may take a few weeks.

Don’t be so hard on yourself 

Getting an infestation can be devastating to any plant parent’s morale. So realize that no one is immune. Pesky pests come with the territory of plant parenthood. The best thing you can do is to be observant so you can spot any early issues and treat them right away. 

Toni Reale is the owner of Roadside Blooms, a unique flower and plant shop in Park Circle in North Charleston. It specializes in weddings, events and everyday deliveries using nearly 100% American and locally grown blooms. Online at www.roadsideblooms.com. 4610 Spruill Ave., Suite 102, North Charleston.