Episode Details

In this episode of the Beyond the Garden Basics newsletter/podcast, we engage in an in-depth discussion about weed killers with Debbie Flower, America’s favorite retired college horticultural professor. We delve right into the complexities of weed management, addressing the various options available while navigating the maze of products at our local big box stores.

As we stand before a daunting wall of weed killers, the conversation brings clarity to the overwhelming choices, shedding light on the distinctions between the products and their formulations.

We start by tackling the widespread confusion surrounding Roundup, a brand historically synonymous with glyphosate. As glyphosate is being phased out, we explore the newer formulations that have replaced it. Many consumers may assume that Roundup still contains glyphosate, but Debbie explains that consumers must be vigilant in understanding the fine prints of these products.

According to the University of Tennessee publication, “Update on Roundup-Branded Herbicides for Consumers”, Roundup weed-killing products now encompass a range of active ingredients that may vary significantly in toxicity and efficacy. We emphasize the importance of reading labels thoroughly, highlighting the legal implications of using herbicides incorrectly.

Debbie expands on the shift in chemical composition within Roundup by introducing us to several active ingredients like Diquat, Fluazipop, and Triclopyr. We discuss the implications of using these chemicals, including their varying half-lives and their potential effects on soil and nearby desirable plants.

Notably, Debbie reminds us that some products can render soil inhospitable for new planting for extended periods, which is crucial information for gardeners planning their next steps after weed control.

Throughout our discussion, we touch on the critical aspect of safety. Both Debbie and I stress the significance of protecting oneself when applying any chemical herbicide. We explain how understanding the signal words such as “caution,” “warning,” and “danger” on product labels can help consumers navigate the toxicity levels of different herbicides.

The conversation leads us to the point that, while chemical weed control can be effective, many gardeners often overlook traditional methods, like manual weeding and mulching, which can be safer and more environmentally friendly.

We tackle alternative options popular on some Internet gardening sites, including vinegar as a natural weed killer but quickly highlight the hazards of using 30% vinegar, which is often found in the cleaning aisle rather than the gardening section. This topic was also covered in depth in the September 3, 2024 edition of the “Beyond the Garden Basics” newsletter.

We caution gardeners about the need to treat such products with care, as they can be more harmful than conventional herbicides. This well-rounded dialogue between us brings to light both the benefits and the risks associated with various gardening techniques and products.

As we progress, we dig into the technical side of weed killers—discussing how different chemicals are absorbed by plants, persistence in soil, and the necessary wait times before replanting. Debbie provides valuable insights into the environmental impact of chemicals leaching into the soil and waterways and how this can affect crops and landscaping efforts. Our conversation is not merely about identifying the right products but also understanding their broader implications on health and the environmen