It’s a beautiful time of year — redolent with the smell of lilacs, the warmth of the sun, the deep greens of lawns and trees, and the happy sounds of birds and kids playing ball… But to keep yards and ballfields looking pristine, many homeowners and municipalities use chemicals that can kills pets, and harm humans. Many of the over 1,500 chemicals used in the thousands of rodenticides, herbicides, and pesticides licensed in the U.S. for home and municipal are toxic.

Probably the most notorious of these is glyphosate, the active ingredient in Roundup and similar brands of brush killers. Glyphosate causes cell death in the dopamine rich centers of the brain, so has been associated with Parkinson’s Disease: in fact, living close to golf courses, where herbicides are usually used, is associated with an increased risk of this disease, according to a 2025 study done by the Mayo Clinic. (Some of the newer formulations of Roundup contain substitutes. However these chemicals have their own problems; one of them — diquat — is even more toxic than glyphosate and is banned in the European Union.)

Other active chemicals, like the pyrethroids (synthetic derivatives of the pyrethrins, which are produced by chrysanthemums and naturally repel pests) cause trouble, too. According to at least three recent peer reviewed studies in the literature, pyrethroids can cause neurobehavioral problems in the offspring in women who are exposed in pregnancy.

The neonicotinoid pesticides are neurotoxic, killing not only pests, but beneficial insects like bees. Bee populations, which are plummeting, are responsible not only for honey, but 75% of the world’s fruits, vegetables, and nuts — 35% of the global food supply. Neonicotinoids are the active ingredients in dozens of products marketed to spray on lawns, flowers, and fruit, manufactured by companies like Bayer Advanced and Scotts. For a complete list, go to www.beyondpesticides.org.

Taken together, home pesticide and herbicide use is associated with increased risk of breast cancer, testicular cancer, asthma, depression, increased blood pressure, and obesity. And scores of studies, utilizing questionnaires and measures of urinary metabolites of pesticides in pregnant women, have shown that there is an increased risk of low birthweight, hypospadias, developmental delays, neuroblastoma, retinoblastoma, Wilm’s tumor, and brain tumor, leukemia, and lymphoma in their unborn children.

Of course, humans aren’t the only animals that can be poisoned by pesticides. Dogs, like little humans, like to play, roll around in, and lick the grass. One study showed that dogs in households with chemically treated lawns are four to seven times more likely to develop bladder cancer.

Town department of public works, recreation departments and schools are required to have plans that use integrated pest management that minimize use of potentially harmful pesticides and herbicides on municipal property. However, school departments are sometimes pressured by parents of young athletes to have tidy weed-free fields — even if those weeds aren’t getting in the way of play, so they are forced to use toxic herbicides.

But, says Dr. Stephen Franz, a pathobiologist who has consulted on the harms of pesticides in New York, California, and South Hadley, where he helped pass a Board of Health regulation to limit use of insect and weed control to only IPM methods, “I would doubt that any parent would want their child to suffer serious disease like cancer that could result from exposure to harmful herbicides.”

Surprisingly, potted plants and cut flowers present similar problems. A large 2024 study from Germany and Austria revealed that over 90% of them carried residues of pesticides that were toxic to bees. Forty percent of the plants, and 72% of the cut flowers had residues that were poisonous to humans.

Meghan Hastings, co-owner of Dave’s Natural Garden, told me that flowers typically sold in florists and supermarkets are grown as monoculture — one kind of flower spread over acres, and “pests feel like kings” in those fields — so growers always use pesticides. She sells a variety of beautiful flowers, but they are grown in greenhouses, with no sprays — only tiny parasitic wasps used to control aphids.

Do we homeowners really need perfect lawns and weed free gardens? Monolithic lawns are sterile environments. I keep ours long, using only organic fertilizer, tolerating weeds which flower and encourage pollinators. I mulch our gardens well. We have a feeder and bird baths and have an unmowed section which bees love.

To eradicate poison ivy, I use a mixture of a gallon 30% vinegar, a cup of Morton’s Ice Cream Salt, and a tablespoon of dish soap. It works great! We have a company from South Hadley spray our lawn and bushes monthly with a mixture of clove, mint, and mineral oil to control mosquitos and ticks (which I still check for after coming inside).

We never have to worry about us, our pets, or grandkids getting poisoned. And when I was resting on a hammock swing in our backyard last week, I saw or heard 17 different species of birds, including feathered friends who’ve made homes in all six birdhouses I put up. Isn’t that preferable to risk sickening ourselves, our children, and pets to have that “perfect lawn?”