By Lee Miller, Extension Master Gardener volunteer
While not exactly a self-improvement article, let’s learn about ways to incorporate less toxic pesticides into your integrated pest management (IPM) program for your landscape and garden plants. Pesticides include insecticides, herbicides, fungicides, disinfectants, repellants and biopesticides. Lower-toxicity pesticides include natural horticultural oils and insecticidal soaps, botanical extracts, microbial insecticides and various minerals such as sulfur, kaolin clay, silica gel, boric acid and diatomaceous earth just to name a few. Many conventional, man-made (synthetic) and organic (mostly natural) products can also be classified as lower toxicity.
After diagnosing the problem and before you reach for any pesticide–whetherconventional, organic, or natural–it should be investigated to ensure it targets the plant and pest you wish to treat while strictly adhering to application directions. Any chemical in large enough doses can create a risk. Look for the “signal word” in large print on the label that alerts users to special hazards; “Caution” means low toxicity. No signal word means the EPA has deemed the pesticide is “practically non-toxic”. Ideally, less toxic pesticides should be more gentle on the plant, its environment, beneficial insects and other organisms if used as directed.
Homemade products may not meet the same standards of commercial products based on the ingredients and efficacy testing. Take into consideration that a less toxic treatment that requires multiple applications may create more stress on a plant and its environment than a single conventional approach and an organic pesticide may be more toxic than a synthetic one.Use Caution with these DIY treatments:
- Using household liquid dishwashing soap (a synthetic detergent) as a surfactant diluted with water will kill soft bodied insects but may cause phytotoxicity (plant damage). Antibacterial liquid soap is considered a pesticide and is not for use outdoors since it can severely disrupt microorganisms. Dishwashing soaps have many formulations such as grease cutting, concentrated formulas, essential oils, etc. that can strip the thin protective layer of wax on leaves and fruits.
- Baking soda (sodium bicarbonate) has long been used as a homemade fungicide on some forms of fungus when mixed with water and horticultural oil. It is best used to prevent fungus as it creates an alkaline environment that retards fungal growth but overuse will accumulate salts on the foliage and disrupt the pH in the soil. Don’t apply more than once a week.
- Using vinegar to kill vegetation (including turf). Household vinegar is 5% acetic acid and it won’t kill weeds. Horticultural vinegar is 20-30% or more acetic acid and its “signal word” is “Danger”. It requires protective clothing including waterproof gloves, N95 mask, face shield and eye goggles. It works best on young weeds but doesn’t affect the root system.
- Mothballs are a pesticide labeled for indoor use to kill moths, silverfish and other fiber insects. Do not use outdoors!
Resources:
- Less Toxic Insecticides
- Insecticidal Soaps for Garden Pest Control
- Natural Products for Managing Landscape and Garden Pests in Florida: (Check out the table link at the bottom of article)
- Insecticides Low Toxicity Options
- Managing Plant Pests with Soap
- Baking Soda
- Vinegar: An Alternative to Glyphosate?
