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What are Pre-emergents? Thank you. Juliana


Pre-emergents Hi Juliana,
Thank you for a great question. Pre-emergents sound like the perfect solution to prevent weeds in your lawn and gardens, but they do far more harm than good. Our colleagues at the Perfect Earth Project answered it best:

"Pre-emergent are herbicides designed to kill weed seeds BEFORE they sprout. They are usually granular and are applied to lawns and flower beds in the spring, but they persist for three months - that means prolonged time for human exposure. Popular brands include Preen, Scott's HALTS, Nitrophos Barricade, Anderson's Barricade, and Snapshot 2.5 TG, and Lesco.

Below we have gathered important information about some typical active ingredients and their effects:

Dithiopyr - endocrine disruption, toxic to bees, fish and aquatic organisms. Isoxaben - possible carcinogen, kidney/liver damage, toxic to birds. Oxyfluorfen - possible carcinogen, reproductive, birth and development effects, kidney/liver damage, skin irritant, toxic to fish and aquatic organisms. Oryzalin - kidney/liver damage, skin irritant, birth and developmental effects, toxic to fish and aquatic organisms. Prodiamine - carcinogen, neurotoxicity. Pendimethalin - extremely toxic to fish and aquatic organisms. Trifluralin - extremely toxic to fish and aquatic organisms.

Also, since the active ingredient is usually only 1% ... what are the 99%"other ingredients"? They are often a blend of equally toxic ingredients that amplify the deadly effectiveness, which means they are even more toxic for you too.

Safe alternative? Although corn-gluten is often recommended as an organic preemergent for lawns, it is expensive, and timing is too critical to be effective, so we don't recommend it. The PRFCT nature-based approach to weed control is to outcompete them. Overseed lawns in the fall or early spring before weeds germinate. In shrub and flower beds plant many small plants close together, leaving little to no space or sun for weeds. More plants is always a better option for filling space than bark mulches."

The Sprigs & Twigs 100% Organic Lawn Care program embraces the Perfect Earth Project advice. We create strong, healthy, clean lawns that crowd out weeds without any harmful chemicals. For more information, visit our website,, and call our office at 860-235-0752 for a free consultation and estimate.

Printed with permission from Perfect Earth Project, 962 Springs Fireplace Road, East Hampton, NY 11937

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About Linda Lillie

Linda K. Lillie is the President of Sprigs & Twigs, Inc, the premier landscape design and maintenance, tree care, lawn care, stonework, and carpentry service provider in southeastern Connecticut since 1997. She is a graduate of Connecticut College in Botany, a Connecticut Master Gardener and a national award winning landscape designer for her landscape design and landscape installation work.


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