Controlling the pests that impact your houseplants
Published at
A few decades ago we bought an areca palm. It wasn’t until we got it home that we realized it was heavily infested with spider mites. We kept it away from the other houseplants and tried several techniques to help it recover from the damage. After about a year I finally gave up and let it die.
While “pest” is a generic term that includes plant diseases, weeds, arthropods, and vertebrate organisms, we will focus on arthropods for this article. Pests usually come into our homes on new plants or plants that have been brought in from the outside. As with outdoor pests, an integrated pest management approach is best.
The conditions we provide for our houseplants are pretty good conditions for many of the pests that infest them.
Prevention
Prevention is always the best approach to pest control. A healthy plant is better able to fend off pests. Proper water, light, temperature and fertility will help plants use their natural defenses. Here are links to previous articles on houseplant growing conditions:
RELATED | Effectively lighting your plants to ensure optimal growth
RELATED | Using water to successfully grow houseplants
RELATED | Understanding different nutrients your plants need and how to care for them properly
In addition, the selection of healthy plants is very important. Inspect the plant for pests or symptoms of their damage before purchase. Newly purchased plants and those brought in from outside should be quarantined for at least two weeks and checked regularly for pest issues. If plants are severely damaged and not valuable, it may just be best to discard the plant and soil and start with a new one. The pot can be disinfected with a 10% bleach solution and reused.
Non-chemical options
Non-chemical options will require repeated applications.
- If the damage is very localized, you can remove infested plant parts. If there is severe damage, you can start many houseplants with new cuttings in fresh, sterile potting soil. Be sure the cuttings are free of pests. Throw out the parent plant to avoid infesting your new one.
- Some situations may call for re-potting the plant. Be sure to wash the roots off and re-pot them in a clean pot and fresh soil.
- Hand pick or wipe pests off the plant. Scale insects may need to be scraped off with a fingernail.
- Wipe leaves regularly with a moist cloth. Do not use leaf shine products. Use a different cloth for each plant.
- A handheld shower nozzle can be used with a stiff spray of cold water to dislodge many pests. Pay particular attention to the underside of the leaves.
Chemical options
If the plant is valuable and non-chemical options have not been effective, then a chemical application may be necessary. Insecticidal soaps can be effective on soft-bodied pests such as aphids, white flies, mealy bugs, thrips and spider mites.
Proper identification of the pest is very important. Some pesticides kill on contact, and some are systemic which requires the pest to eat part of the plant.
Insecticides will not work on spider mites — a miticide will need to be used. For soil-borne pests, the best response may be with a soil drench. Very few pesticides are labeled for indoor use. Be sure the product is labeled for your intended pest and plant.
Horticulture Educator Ron Patterson can be reached at (208) 529-1390.
In the Garden is sponsored by ProPeat, which is dedicated to delivering solutions for any of your professional fertilization needs. Whether you need to reduce the harm to soils and the environment, or you're interested in the latest nitrogen, carbon and biochemical technologies, ProPeat is the perfect fit.