The Effects of Roundup on Lawns: What Every Homeowner Should Know
Tim Malterer • March 3, 2025
Malterer’s Landscaping & Lawn Care
When it comes to keeping your lawn green and weed-free, many homeowners turn to Roundup as a quick solution. However, is Roundup really the best choice for your lawn? While effective at eliminating weeds, its impact on grass, soil health, and the environment raises concerns. At Malterer’s Landscaping & Lawn Care, we believe in educating our customers about the pros and cons of lawn treatments, so you can make the best decision for your landscape.
How Roundup Works: The Science Behind the Spray
Roundup is a non-selective herbicide, meaning it kills all plants it comes into contact with—including your grass. Its active ingredient, glyphosate, works by blocking an essential enzyme that plants need to grow. When applied, the plant absorbs the chemical through its leaves and transports it to the root system, effectively killing the plant from the inside out.
While this makes Roundup a powerful tool for cracking down on stubborn weeds, it also means that any accidental overspray can harm your lawn, flowers, and surrounding plants.
The Impact of Roundup on Your Lawn
1. Kills Grass Along with Weeds
If Roundup is applied directly to your lawn, you will see the grass turning yellow and dying within a few days. Unlike selective herbicides that target only weeds, Roundup does not discriminate—once applied, there’s no turning back.
2. Affects Soil Health
Many homeowners believe that Roundup breaks down quickly in the soil, but research shows that glyphosate can persist for weeks or even months depending on weather conditions. Over time, this can:
✔ Reduce beneficial microbes that keep your soil healthy.
✔ Disrupt root systems, making your grass less resilient.
✔ Hinder new growth, leading to patchy, unhealthy turf.
3. Risk of Chemical Drift & Runoff
Applying Roundup in windy conditions or before rainfall can lead to unintended damage:
✔ Drifting onto nearby grass and plants, causing accidental die-off.
✔ Contaminating water sources if it washes into storm drains.
✔ Leaching into deeper soil layers, which can affect root growth over time.
If you live near flower beds, vegetable gardens, or water sources, using Roundup may pose environmental and ecological risks beyond just your lawn.
Better Alternatives for a Healthy, Weed-Free Lawn
1. Selective Herbicides
Unlike Roundup, selective herbicides target only broadleaf weeds while sparing your grass. Look for products with:
✔ 2,4-D – Targets dandelions, clover, and chickweed.
✔ Dicamba – Works on tougher weeds like thistle and knotweed.
✔ Triclopyr – Best for woody or vine-like weeds.
2. Natural & Organic Weed Control
✔ Vinegar-Based Herbicides – Effective for killing weeds without harming soil.
✔ Corn Gluten Meal – A natural pre-emergent that prevents weed seeds from germinating.
✔ Boiling Water – A great spot treatment for cracks in sidewalks and driveways.
3. Proper Lawn Care Techniques
✔ Mow at the correct height – Taller grass blocks sunlight from reaching weeds.
✔ Overseed bare spots – Filling in patches prevents weed takeover.
✔ Aerate & fertilize – Promotes a thick, healthy lawn that naturally crowds out weeds.
Final Verdict: Should You Use Roundup on Your Lawn?
While Roundup is effective for killing weeds, its risks often outweigh its benefits for home lawn care. If misapplied, it can destroy your grass, harm your soil, and impact the surrounding environment. Instead of resorting to non-selective herbicides, choosing targeted weed control methods and maintaining proper lawn care practices will result in a lush, vibrant, and healthier lawn—without the long-term consequences.