Plant Parent Basics: Pests
An adult fungus gnat. Image courtesy of Planet Natural Research Center.
As part of our feature series, Plant Parent Basics, in this article you will learn about common house plant pests and how to avoid them.
How do I identify plant pests?
Fortunately, plant pests are usually easy to spot. You’ll see them around the stems and leaf nodes or in the soil. They like to feed off the plant nutrients where they are the juiciest, for example, where the stem joins a new leaf, when a stem joins the trunk and in the soil with the plant’s roots.
A serious attack of most pests leads to wilting, yellowing and leaf fall.
Yellow sticky traps are especially helpful in monitoring adult whitefly and fungus gnat populations.
Spider mite infestations are characterized by fine webbing on leaves and stem. Image courtesy of Gardener’s World.com
What are the most common plant pests?
The most common houseplant pests include:
You can click on any pest in this list to learn more specific information on how to identify, treat and prevent it.
Up close and way too personal with scale. Image courtesy of Epic Gardening.
How do I get rid of plant pests?
Wash them away.
Mealy bugs can be dislodged with a steady stream of water. Repeat the treatment as necessary. This is best for light infestations.
Spot treatment with isopropyl alcohol.
On small infestations on houseplants, a 70% or less solution of isopropyl (rubbing) alcohol in water may be dabbed directly on mealybugs with a cotton swab to kill them or remove them.
Use neem oil.
Neem oil is an organic oil derived from the neem tree. Use according to label instructions.
Give your plant a soapy suds down.
Make your own insecticidal soap by using a gentle dish detergent or similar soap product free of perfumes and additives that might harm plants. Mix the soap in a weak concentration with water (starting at 1 teaspoon per gallon and increasing as necessary). Spray on plants. Depending on the severity of infestation, you may need to repeat this method weekly until the infestation is completely gone
Try beneficial nematodes.
Beneficial nematodes are microscopic insects that seek out and destroy over 230 kinds of soil dwelling and wood boring insects but will not affect humans, animals, or plants. This method is particularly useful for severe infestations. Be sure to follow the directions on the packaging. Get yours here.
Prune it away.
Simply trim the affected part of the plant and discard it. Learn more about pruning practices here.
Repot as a last resort.
If all else fails on your eradication front, you can repot your affected plants. Follow our guide to repotting, and be sure to use fresh soil and a clean pot with adequate drainage.
Whitefly infestation on a fiddle leaf fig. Image courtesy of Epic Gardening.
How do I prevent plant pests?
Make sure you have the right air flow and temperature.
Correct watering and air circulation is the best way to prevent fungus gnats. Keeping your plants clean and free of debris is also key. As you do your watering routine, check your plants for abnormalities and/or bugs and remove any dead foliage. Learn more plant housekeeping tips here.Mealybugs thrive in moist, warm environments. Unfortunately for plant parents, this is also the environment most plants thrive in.
Practice good housekeeping.
Keeping your plants clean is the best way to prevent pests. It also encourages new growth. As you do your watering routine, check your plants for abnormalities and/or infestations and remove any dead foliage. You can also wipe down the leaves of your larger plants, if you have some, with a wet paper towel. Learn more plant housekeeping tips here.
Water with hydrogen peroxide.
Hydrogen peroxide helps encourage healthy roots because of its extra oxygen molecule. This extra bit of oxygen better enables the roots to absorb more nutrients, which means faster, healthier, and more vigorous growth. And as a bonus, hydrogen peroxide can help discourage unwanted bacteria/fungi/bugs that may be lurking in the soil. To give plants an added boost of oxygen for pest control using the 3% solution, add 1 teaspoon per cup of water in a spray bottle or watering can and apply to plant.
Quarantine infested plants immediately.
Plant pests spread very quickly, so it’s important to quarantine any plant(s) you suspect may have an infestation as soon as possible. This will help keep it from spreading to your other plants.
If you’re unsure how to diagnose your plant, please reach out to us via email or a direct message via Instagram. Pictures are encouraged.
Mealybug infestation on a succulent plant. Image courtesy of Needles and Leaves.