Keeping Indoor Plants Healthy
- Common sense long-term approach to pests and disease control
- Reduction of risky pesticides that pollute indoor air and surfaces
- Organic methods are safer for children, pets and plants
- Emphasis on prevention and awareness
- Economical – even free! - as well as effective
Local Advice for Local Gardeners
Plants that live with us in the house are our friends, adding life, humidity, cleaner air and a natural sense of health. Keeping them thriving in the most healthy way is what integrated pest management – IPM – is all about. There’s really no reason to use synthetic chemicals to control houseplant pests and diseases, for there are many simpler, safer options. They start with good cultural habits, a holistic mindset of paying attention to your plants and what they need, and choosing what to do in a safe progression of treatments.
An ounce of prevention
Start off choosing houseplants that will suit the growing spots you have to give them, and you’ll automatically be off to a healthier start. Check our How to Grow Foliage Houseplants care sheets for more information.
At the nursery, buy high quality, and check plants for pests. Read labels to see what situations and care the plants need and if you can provide them. At home, give high-light plants lots of sun, medium-light plants more shade, and bump up humidity, which reduces whiteflies and other pests. If the growing area feels fresh, like a place you’d like to be, it’s good for plants too. Water wisely to avoid rot or, conversely, wilting. Resist temptation to over-fertilize; if you see brown leaf tips, switch to rainwater and stop fertilizer.
When you repot, use clean new potting soil and new pots or ones that have been through the dishwasher on high heat. Keep cutting tools clean. Avoid splashing water on plants when they can’t dry off quickly, and pick off infected and dead leaves and destroy them. Keep an eye on your plants, checking under leaves for pests and monitoring for potential diseases, so you can decide if a small infestation is okay to live with, and choose what steps to take – if any are actually needed.
The most common pests and their simple treatments
Spray off with strong spray of water (both leaf sides) for a few days:
- Aphid: Groups of small, sometimes translucent bugs can be green, brown, orange, white, black, often on newest growth.
- Mite: Ultra-tiny; you’ll see the stippled damage and/or webbing on leaves rather than the actual insects.
Dab directly with rubbing alcohol on a cotton swab:
- Mealybug: Small white cottony waxy tufts usually under leaves or in crevices.
Rub off gently by hand and monitor for more:
- Scale: Hard to detect, but usually accompanied by sticky residue; can be tiny round brown hard shells.
Insecticidal soap spray, thoroughly soaking plant:
- Whitefly: White spots that fly up when plant is disturbed.
Your own pets: Cats not only chew plants but surreptitiously use the soil for litter boxes. Move the plants out of reach.
A choice of pest treatments - begin with non-toxic and work up to most potent
- Doing nothing, if pests aren’t too damaging
- Mechanical methods, including sprays of water from the hose, hand-picking pests, yellow strip sticky traps
- Insecticidal soap and horticultural oil for insects and fungal disease
- Natural botanical insecticides/fungicides from plants (pyrethrum, neem, powdered cinnamon, citrus)
- Mineral-based insecticide (sulfur)
- The last resort – targeted application of chemical controls at specific life cycle times
Did you know...For the very squeamish, there are even portable insect bacuums for houseplants that work will when used regularly on whiteflies in particular.
Written by Graham Rice