Pests: What to Look for on Indoor Plants

Leaf&Paw.com

It’s time! Finally, the weather is warm and you can open your windows after a long, cold winter. However, winter is harsh on indoor plants, and usually leaves them with pests problems. I’ve listed the typical pests I look for on my plants, complete with photos of my once infected friends. My plants are just as excited about spring as I am, and they deserve a makeover before their favorite time of year.

Monstera Deliciosa sun damage.
Some damage may be caused by winter conditions, like dry heat.

In New York, winter can be horrible, but I’ve embraced it after my indoor plant collection has grown. It gives me a time to get in touch with them, check for pests, learn their watering patterns and sunlight tolerance, and how they like their coffee. Come summer, they spend most of their time on my enclosed porch or outdoors. My house becomes empty and a bit pale without the jungles in every room. To be honest I love having everyone in my house, but know they are much happier in a humid porch. On the plus side, my house  suddenly becomes much bigger.

Plants on porch
Everybody outside for the spring.

Pest problems are common in winter though; harsh heat, dry conditions, and cold drafts do a number on them. I usually loose one or two every year just because I live in an historic house with irregular heating spots. Keeping plants alive all winter is hard. My hedgehogs need a warm temperature, so most of my rooms are a toasty 69-71 degrees Fahrenheit. This makes it dry for indoor plants that love humidity. And that’s like, all plants.

Cats and plants sunbathing.
Cats and plants sunbathing. Typical all day affair.

Speaking of temperature, it gives pests a breeding ground. All winter and, especially once the weather warms, I check for bugs. I search undersides of leaves, stems, tops of the soil and all crevices. They’re are sneaky little bastards and can be anywhere. ANYWHERE. So bring out your best Sherlock Holmes magnifying glass and go bug hunting.

What you see: Tiny white fluffy things on stems and leaves.

The Pest: Mealybugs

Mealybug pests
Mealybugs on my Jade.

These are mealybugs and the most common indoor plants problem. They offer nothing to the world and only suck plants dry of energy leaving them to slowly die a horrible death. They are small and fluffy, usually surrounded by some kind of webbing and are a bloody mess if you squish them. That being said, destroy them upon first sight. They’re most commonly under leaves and along the stems. If there are only a few (and look at the WHOLE plant), take a cotton swab/ball drenched with rubbing alcohol and place over bugs. This will suffocate them. Either wipe them off or remove with tweezers until all visible bugs are gone. If there is any white fluff  embedded in leaves, dredge the section in alcohol as well. Place plant in quarantine until there’s no sign of the devil creatures.

Mealybug pests on Bird of Paradise
Mealybugs on Percy my Bird of Paradise.

If it looks more like a house party of mealybugs, use your best judgment. Try the alcohol method as many times as you need, but if there’s a lot of bugs you will need to go to your nearest garden center for their best systemic pest removal. A systemic is a pesticide that gets absorbed into the roots and stem and continues to work even after the initial applications. This will have to be applied outside, and always follow pesticide directions thoroughly.

Mealybug pests on Bird of Paradise
More on Percy, he didn’t have a good winter.

What you see: Brown or white flecks on leaves

The Pest: Scale

Scale pest damage on Staghorn fern.
You can see the light green spots where the scale was. Also, a fern hand!

I’ve never had a problem with scale until I blindly purchased a Staghorn fern from a garden center. He was covered in little white and brown specs, which I didn’t notice until I got home. It wasn’t mealy bugs, but scale pests, and they were slowly sucking life out of my new plant. My fern above shows where each scale bug was, you can actually see the chlorophyll depleted. So, so sad. I actually used a combination of dish soap and water to get rid of them, about 2 Tbsp per gallon of water. I submerged the top of the plant and left it for a few minutes. Anything left on the plant I handpicked off slowly, and, hours later, he was good as new. Ferny is on the mend, but the scale scars are still around. Lesson learned-  always, always check plants for bugs before buying.

White Scale on Staghorn Fern
Bit of white scale on my fern.

What you see: Tiny gnats flying around the soil

The Pest: Fungus Gnats

While the name “fungus gnats” is enough to make be barf, these are the worst pests of the bunch because they are incredibly annoying. The don’t just buzz around plants, but food, pets, people, your mouth, eyes, computer screen, sugary drinks, coffee, dear lord make it stop! So I did and here’s how.

Fungus gnat pests
DEAD fungus gnats. The best kind.

This took some digging. Literally. They live in the soil of houseplants so you can’t actually see them. The larvae feeds on fungi in soil, plant roots, or starter plants and seedlings. These then grow into the monsters you see flying around your head at night. Soggy wet plants are their favorite, so check your soggy plants without drainage holes first. Sometimes gnats leave a slimy trail on the top of the soil, but that’s not always visible. You really have to dig.

Fungus gnats
Getting rid of fungus gnats using sticky traps.

The first step, once you find the infected plant, is drying it out. The gnats can’t survive without sign fugusy water, so by drying the plant out you are killing the larvae. Next drain any extra water that is left after watering your plant (this includes water in saucers). Step two is to put the plant outside or in another location until the gnats have died down. If that isn’t an option (maybe it’s winter outside), secure some fly paper all around the top of the soil. Monitor how many get stuck everyday then rejoice when the paper is clean. If you want to go the extra mile, clean up any debris or dead leaves or roots around the plant.

Moisture meter!
I love my moisture meter for detecting water levels in big plants. This guy is a rescue on the mend, he suffered from severe under watering and mealybugs.

There are other pests of course I haven’t mentioned, but these three are the top offenders. Keep in mind that if a pet-friendly plant is infected, don’t use chemicals (such as insecticides) on them. If the plant is then ingested by a cat or dog, they can cause serious stomach issues. After all, chemicals are poison, even “organic” ones. The most natural approaches for pest removal I have listed above, using isopropyl alcohol, dish soap, and fly traps pose no threats to pets. Always be mindful of furry friends when destroying pest enemies. I hope this helps and happy spring!