For more than five decades, glyphosate has been the active ingredient associated with the trade name Roundup®. Glyphosate is a non-selective herbicide used in many home landscape applications to control a wide range of grasses and broadleaf plants. It is non-volatile, which limits its potential for drift and damage to nearby desirable plants. Additionally, glyphosate is unavailable to plants in the soil, allowing for planting within days of application, rather than weeks or months as with many other herbicides.
Roundup No Longer Equals Glyphosate
This herbicide is so commonly used that the brand name Roundup is often used interchangeably with glyphosate. Starting in 2024, however, new formulations of herbicides were released that use the brand name Roundup, but do not contain glyphosate. Instead, they contain a combination of multiple active ingredients. In some cases, this mix is intended to create a product that can be used in a similar way to glyphosate, and in other cases, it is a product that acts selectively for use in settings like lawns or for brush control. This creates a significant amount of confusion among gardeners who instinctively grab Roundup from the shelf, intending to use it as they always have.
These changes to the Roundup-branded herbicides mean it's important for gardeners to look more closely at the label to ensure they are purchasing the product aligned with their intended use. When not used in accordance with the label directions, these products are costly investments that may be less effective on target weeds, more likely to damage desirable plants, and could have long waiting periods to replant after treatment (not to mention it's against the law!).
What is Changing?
New formulations of herbicides are being sold under the Roundup brand name. These products contain a mix of active ingredients that differ from glyphosate in their modes of action, weed types controlled, movement through the plant and soil, time to see results, residual action in the soil, and recommended use in the landscape.
Details about many of the active ingredients found in new formulations of Roundup-branded herbicides can be found below.
| Active Ingredient | Sensitive Weeds | Type | Residual Activity in Soil | Time to Symptoms | Time to Death | Volatility Risk |
|---|---|---|---|---|---|---|
| Dicamba | broadleaf, woody | systemic | moderate | 1-3 weeks | 3-5 weeks | high |
| Diquat | broadleaf, grasses | contact | low | 2-24 hours | 1-3 days | low |
| Fluazifop | grasses | systemic | moderate | 2-3 days | 3-4 weeks | low |
| Glyphosate | broadleaf, grasses, woody | systemic | low | 4-10 days | 2 weeks | low |
| Imazapic | broadleaf, grasses, sedges | systemic | high | 3-5 days | 2-4 weeks | low |
| MCPA | broadleaf | systemic | moderate | 1-3 days | 3-5 weeks | high |
| Pelargonic Acid | broadleaf, grasses | contact | low | 0.5-2 hours | <24 hours | moderate |
| Quinclorac | broadleaf, some grasses | systemic | high | 3-5 days | 1-2 weeks | low |
| Sulfentrazone | broadleaf, sedges | systemic | high | 1-2 days | 1-3 weeks | low |
| Triclopyr | broadleaf, woody | systemic | moderate | 1-3 days | 3-5 weeks | low |
| Active Ingredient | Symptoms | Mode of Action | |
|---|---|---|---|
| Dicamba | bending and twisting of stems, leaf cupping and curling | causes uncontrolled cell division and growth, destroying plant tissue | 4 |
| Diquat | quick wilting and browning of leaves | disrupts the process of photosynthesis | 22 |
| Fluazifop | yellowing and browning of young leaves starting at growing points, older leaves turn purple, orange, or red | prevents the building of new membranes required for cell growth | 1 |
| Glyphosate | yellowing and browning starting with new growth | prevents protein synthesis needed for growth | 9 |
| Imazapic | yellowing and browning starting at new growth | prevents the formation of certain amino acids, causing death | 2 |
| MCPA | bending and twisting of stems, leaf cupping and curling | causes uncontrolled cell division and growth, destroying plant tissue | 4 |
| Pelargonic Acid | quickly develops dark, water-soaked appearance, followed by wilting and death | destroys cell walls, causing collapse and death | 0 |
| Quinclorac | Grasses: yellowing, wilting, browning starting at new growth Broadleaves: yellowing leaves, mild twisting of stems, and leaf cupping | causes uncontrolled cell division and growth, destroying plant tissue | 4 |
| Sulfentrazone | quick browning of leaves | destroys cell membranes causing cells to dry out | 14 |
| Triclopyr | bending and twisting of stems, leaf cupping and curling | causes uncontrolled cell division and growth, destroying plant tissue | 4 |
The Future of Glyphosate
While products with the active ingredient glyphosate are still available on some store shelves under different names, it is likely that they will become less available to homeowners in the coming years. This means that gardeners will need to be more savvy about their herbicide selection and use. Herbicide users will need to know what type of weeds the herbicide formulation is intended to control so it can be used most effectively. It will be particularly important to understand the residual activity of the product, as some formulations may require a wait of as little as 14 days to replant, and others could be 120+ days. Some formulations will readily be absorbed by leaves and others by both leaves and roots, making them more likely to negatively affect nearby desirable plants.
It's always been important to read and follow label directions on all herbicides. Now, more than ever, it will require a more discerning eye to use the right product in the right way.
Additional Resources
- Update on Roundup-Branded Herbicides for Consumers. University of Tennessee (PDF)
- EPA Herbicides Causal Analysis/Diagnosis Decision Information System (CADDIS)
- Shaner, D. L., Weed Science Society of America. Herbicide Handbook. Tenth edition. Lawrence, KS: Weed Science Society of America, 2014.
Photo credits: 1: Mary Ann Hansen, Virginia Polytechnic Institute and State University, Bugwood.org; 2: sheilaf2002/AdobeStock; 3: Sundry Photography/AdobeStock
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on June 4, 2025. The information contained within may not be the most current and accurate depending on when it is accessed.