As any veteran houseplant owner knows, a pest infestation is an eventuality that everyone must deal with at some point in time. The severity and urgency will vary, depending on both the type of pest and variety of plant, which has prompted some to wonder which plants are most susceptible to these common houseplant invaders.
All houseplants attract pests to some degree. Because they are both a food source and are often grown under ideal environmental conditions, any houseplant is at risk of infestation from common pests. Ferns, Peace Lilies, Calatheas, and Hoyas are often reported as “attractive to pests”, but any plant may be susceptible under the right conditions.
As much as we wish we could guarantee your home would remain pest-free as long as you avoid certain varieties of plants, unfortunately, it just doesn’t work like that. The common houseplant pests that we often find in our homes are equal opportunity feeders, gladly taking up residence in any plant that can provide them sustenance and shelter.
Of course, there are plant varieties that are known for being more “pest-resistant,” which does have some truth to it. In fact, the plants with this reputation are often also touted as “low-maintenance” or “easy to care for,” which may be the key to understanding pest resistance.
In this article, we’ll go over why houseplants are attractive to the most common types of indoor pests, some plant varieties that have a reputation for being pest magnets, and the importance environmental factors and plant health have on pest susceptibility.
Why Do Houseplants Get Pests?
If you’ve ever had to deal with a pest infestation on one of your houseplants, you’ve probably uttered (or screamed) the question, “Whyyy?!?”
Why that particular pest? Why this particular plant? Why is this happening to me?
These are all valid questions, and the truth is fairly simple. To a bug, your houseplant is a combination of an all-you-can-eat buffet, protective shelter, and perfect breeding ground all rolled into one living structure, which is often kept at the ideal environmental conditions.
Many of the most common houseplant pests are sap-feeders, in constant search of plant tissue they can tap their mouthparts into to access the sugary, nutrient-dense liquid. Aphids, thrips, spider mites, mealybugs, scale, and whiteflies all fall into this category.
These pests are very common outdoors but are seasonally controlled by the weather and predators. They can get into our homes in a variety of mundane ways but are often carried in on our clothes or other plants that we bring indoors with us. Once inside, they find our houseplants just waiting for them in a climate-controlled, predator-free environment, allowing them to settle in and start growing their populations.
In general, our homes tend to be kept at relatively high humidity levels and consistently warm temperatures, which most pests find ideal. In addition, we tend to water our plants regularly, which provides damp conditions that create good environments for many of these soft-bodied insects to thrive.
Unfortunately, many of the pests we see on our plants prefer the environmental conditions we, as humans, enjoy in our homes. Because our houseplants are the only viable option these bugs have to survive, they become easy targets for any pests that make their way inside.
Are Certain Plants More Susceptible to Pests?
Of course, it makes sense that some plants might be more susceptible to pest infestations than others. A plant with more delicate foliage might not have the same defenses as a variety that has the physical barrier that a thick, waxy cuticle might provide. A plant with woodier stems is probably more protected than one with more supple branch structures.
Ferns
Many people tend to have difficulty with the ferns they bring into their homes. Aside from already having a reputation for being difficult plants to keep happy indoors, ferns are often infested with aphids and scale.
Peace Lilies
Spathiphyllum varieties also tend to be prone to pests. Peace Lilies have the reputation of being the divas of the houseplant world, needing specific light, water, and humidity requirements to thrive. They also seem to attract spider mites, mealybugs, and fungus gnats pretty regularly.
Hoyas
Some Hoya varieties are a bit of a mixed bag. Some folks find Hoyas to be generally pest-free, while others are convinced spider mites have decided they are their favorite meal.
Calatheas
Almost everyone seems to agree that Calatheas are not only difficult to keep happy, in general, but they tend to attract every bug under the sun, especially mealybugs and spider mites.
Now, before you strike off all of these varieties for good, consider this: Arguably, most of the plants we consider “houseplants” around the world are all tropical or sub-tropical varieties that have been bred for their unique, glossy, often turgid, sap-filled leaves.
Although there are several different varieties across many different genera, most houseplants all still resemble something a common pest would find and do find, attractive and delicious.
I just recently lost a several-weeks-long battle to thrips infesting one of my Monstera Deliciosas, one of the most popular houseplant varieties that has a “low-maintenance” reputation. After researching, I’ve found I’m not the only one that struggles with thrips on Monstera.
So, why are the varieties listed above considered more susceptible? Perhaps something else has a bigger impact on pest sensitivity than just variety?
How Environmental Factors Can Impact Pest Susceptibility
Ferns, Peace Lilies, and Calatheas all have a reputation for being hard to care for indoors. All of them require very specific environmental inputs and tend to stress when their needs aren’t being met.
Additionally, the types of pests that commonly attack them (aphids, scale, mealybugs, fungus gnats) mostly thrive in relatively high humidity levels, which these plants require to stay healthy and vibrant.
Humidity levels are difficult to consistently control and can fluctuate wildly. Levels that are too low can stress the plants out. Levels that are higher than necessary create environments where these pests can flourish.
So, rather than just variety alone, perhaps the bigger driver of pest susceptibility are environmental factors such as temperature and humidity, as well as the care practices that impact the overall health of a houseplant.
Overwatering
One of the biggest drivers in plant health and disease occurrence has to do with overwatering. When we water too frequently, keeping the soil too moist, we set our plants up for a myriad of health issues, including root rot, water and nutrient transport issues, and an overall decline in vigor.
We also create an environment that is attractive to pests. For example, aphids, scale, mealybugs, and whiteflies all prefer warm, humid places to feed and breed, and when a stressed, droopy plant is suffering from health issues, it makes it that much easier for them to establish a thriving population.
Additionally, perpetually damp soil is ideal for fungus gnats to develop a solid foothold within the plant, feeding on the decomposing organic matter within the soil.
Underwatering
Alternatively, very dry conditions create their own challenges. Again, the plant can be put under severe amounts of stress, fighting against dehydration while burning, wilting, or dropping leaves.
The dry conditions around the plant, along with the consistently warmer indoor temperatures, create ideal conditions for thrips and spider mites to infest.
In fact, the hotter temperatures we keep our homes at have been known to speed up the lifecycle of many common houseplant pests, meaning that their rate of population growth can speed up significantly.
Low Lighting
Another environmental condition that can impact a plant’s overall health, making it more susceptible to pest infestation, is low light conditions.
When a plant isn’t receiving enough light, photosynthesis within the plant declines, creating a nutrient deficiency over time. This deficiency directly impacts the overall health of the plant.
Often, as a last-ditch effort to secure a new source of sunlight, a plant will begin producing leggy growth to spread as far as it can. This growth is often weak and stringy and can be the perfect target for sap-sucking insects to attack.
Grouping Too Closely Together
A surefire way to make any pest infestation worse is to spread it to other plants in your home. This usually happens when plants are grouped too closely together.
Although some houseplant pests are fairly immobile, you better believe they can find their way onto plants that are touching, or even close in proximity to, a host plant.
Separate from spreading pests, plants that are overlapping or overly confined can create microclimates with poor air circulation and higher humidity levels. These conditions promote everything from disease and pest development to stunted growth and poor overall health.
Proper Plant Care Promotes Healthy Plants
As you can see, the overall health of a plant and the environment in which it lives can have quite an impact on how susceptible it is to pest infestations. Stress caused by improper care and extreme environmental conditions weakens a plant while often promoting the growth of a pest population simultaneously.
Keep this in mind when caring for your houseplants. Consider your plant’s light, temperature, humidity, and spacing requirements when finding a place for it in your home. Proper watering and feeding practices go a long way in keeping your plant healthy and vibrant, so it has the best chance of resisting any pests trying to gain a foothold.
Even notoriously difficult varieties, known to be “pest magnets,” will be stronger and more resistant as long as you take the time and effort to meet their specific needs.
Final Thoughts
While it’s true that some houseplants tend to be more prone to pest infestations, that doesn’t mean you shouldn’t bring them into your home to enjoy. The prevalence of common houseplant pests likely has more to do with the overall health and well-being of your plant rather than the specific variety it is. By ensuring your plant is receiving the proper care it needs, you can keep it strong and vibrant so it is more likely to withstand and resist a potential infestation.