If you’re wanting to “go green” by using more environmentally safe products, yet don’t want troublesome insects and weeds in the landscape don’t give up hope. Here are a few of the more common products that are available and you can feel good about using.
First, I wonder if you’ve ever seen a product that says it’s OMRI® Certified? If you’re wondering what this is all about, let me explain. Products labeled OMRI certified have undergone a rigorous review by the Organic Materials Review Institute. “Organic” or “natural” products without this label aren’t necessarily inferior; they simply don’t carry the prestigious certification or been subjected to OMRI’s review and research. With that said, I recommend reading the fine print of active ingredients on any label to make sure you know what you’re really buying. So here are some of the more common organic products that you may be interested in using. These products may be sold under several different names, but the active ingredient will be listed somewhere on the label.
An interesting product called Spinosad is derived from a naturally occurring, soil dwelling bacterium. It’s reported that the bacterium was found and collected from an abandoned rum distillery on a Caribbean island in 1982 by a vacationing scientist. The pesticide must be eaten by the insect but will not affect insects that feed by sucking (like aphids). The insect will die within one to two days after eating the product. The great part about Spinosad is that it will not harm most beneficial insects.
Sabadilla is a pesticide derived from the seeds of the Sabadilla lily (Schoenoocaulon officinale). It’s sold as either a dust or a liquid and can be found under several different trade names, such as Red Devil or Natural Guard. Sabadilla is considered one of the least toxic of all the botanical, or “safe” pesticides. However, it can be highly irritating to the eyes and can produce sneezing if inhaled, so caution must still be used. Sabadilla works as a stomach poison to insects, effectively killing caterpillars, leafhoppers, thrips, stink bugs and squash bugs. It breaks down very rapidly in sunlight, which may be considered both a pro and a con.
Neem oil is another product receiving considerable attention. Neem is derived from the seeds of the neem tree, a native of India. The Indians and Africans have been using neem for more than 4,000 years as both a pesticide and a medicine. Today, it can be found under names such as Margosan-O, Azatin, or Bio-neem. It can be used to control leafminers, thrips, caterpillars, and mealybugs. Neem works as a growth regulator by inhibiting the insect’s ability to molt to its next life stage. It will not harm earthworms, honey bees, or ladybugs.
Diatomaceous Earth (DE) is a nontoxic insecticide mined from the fossilized silica shell remains of diatoms. Diatoms are single-celled or colonial algae in the class Bacillariophyceae. Just think how impressed your friends will be when you share that with them! DE contains sharp edges that cut the soft bodies of pests, dehydrating and killing them. It’s labeled to control slugs, aphids, grasshoppers, millipedes and sow bugs. The down side to it is that it must be reapplied after a rain or watering.
Bt (Bacillus thuringiensis) is often sold under the trade name Dipel or Thuricide. It’s a wonderful product for killing caterpillars that may be munching on your tasty vegetables, trees or shrubs. The toxins are not poisonous to birds, people, or pets. There’s even a Bt product for controlling mosquitoes. You simply place the product in your birdbath, pond, or whatever water source is a breeding ground for the insects. Bt will not harm birds or animals that may be using the water. It works by killing the larvae in the water, so it may take a few days to see the results, just be patient.
Altosid® is another great product for mosquito control. This is a growth regulator (IGR) that stops mosquitoes from becoming biting adults. (S)-Methoprene will not harm fish, birds, mammals or beneficial insects.
Insecticidal Soap can give quick results for the control of aphids but be aware that the product can damage plants. The product should be applied in the cool of the day and must be sprayed on the insect to achieve results.
Citric acid and clove oil, or horticultural vinegar can be used for weed control in rock areas or flower beds as a spot treatment. These products rapidly kill the top growth of weeds (also grasses and flowers!) when applied to them. Repeat applications might be necessary until the plant finally succumbs.
Corn Gluten has traditionally been used as an animal feed. Today, it’s being used as an organic product to inhibit germination of seeds in controlling annual weeds. Research shows it’s only about 80 percent effective but repeated use over two to three years will show some results.
Keep in mind, even though these are “organic” products, you should always use caution, read the entire label, and follow the directions. Also, keep in mind that organic pesticides may need to be applied more frequently than alternative products. And, some have the potential to “burn” plant tissue, so test it on a small area of your plant before applying it to an entire plant. I hope this helps you have a happier, greener summer!
Linda Corwine McIntosh
Certified Pesticide Applicator, Advanced Master Gardener, ISA Certified Arborist
June 21, 2019