Understanding Herbicides in Landscaping: A Guide for Effective Weed Control

Posted by Bob Dolan at 04/29/2024

Weeds hardscape 02

Within landscapes, most of the unwanted vegetation appears as “weeds”. Weeds are any plants growing where they are not desired. On a golf course, crabgrass or dandelions are considered weeds on greens and fairways. Pulling weeds or rototilling areas are some ways of eliminating weeds but are labor-intensive. Herbicides were created to quickly rid an area of unwanted vegetation, and as herbicide technology has evolved in the last century, there are more options now than ever before. Selecting the best one for your situation is crucial to meeting your customers’ expectations.

There are two common terms used to describe herbicides: Selective and Non-Selective.

Selective herbicides kill specific plants while leaving others unharmed. 2,4-D is a common turf herbicide that can be sprayed on lawns, killing dandelions and other unwanted broadleaf weeds while having no adverse effects on the grass.

Non-selective herbicides, on the other hand, will kill any plant on which they are sprayed. A common non-selective herbicide is glyphosate, the active ingredient in the popular product Roundup®. Glyphosate is the most widely used herbicide in history and has been instrumental in advancing food supplies around the world within the farm industry. It is also dominant in the landscape industry, helping to control unwanted weeds in hardscapes and landscape beds.

Over the past several years, glyphosate has come under scrutiny due to several high-profile lawsuits calling into question the product’s safety. Whether or not glyphosate is “safe” or not is not the immediate question. The fact that Monsanto®, the makers of Roundup, has settled some 100,000 lawsuits for over $11 billion, leads the public to wonder, “where there is smoke, there is fire”.

Because of the public perception that glyphosate may be harmful, alternative non-selective herbicides for weed control are gaining interest and popularity with the public. One of the most popular and well-known alternatives is pelargonic acid with trade names like Scythe®. Another alternative which has increased in popularity, and is derived from a species of bacteria, is glufosinate, with trade names Surmise Pro®, Cheetah Pro®, or Finale®.

Pelargonic acid and glufosinate are post-emergent herbicides. However, it is much easier and cheaper to prevent weed growth than to kill existing weeds. Preventive measures are also safer and longer lasting. Pre-emergent herbicides, products that prevent weeds from growing, are also widely used to help keep weed populations to a minimum. Examples of these products include Snapshot®, Sureguard®, and Specticle G®.

Post and pre-emergent herbicides can be tank-mixed to maximize effects and optimize weed control for your customers. In keeping with the demand for alternatives to glyphosate, combination post and pre-emergent products have appeared that contain glufosinate, pelargonic acid combined with a pre-emergent.

Onmark® is a combination non-selective post and pre-emergent herbicide that can prevent weed growth for up to 3-4 months. Onmark combines three active ingredients to reduce the risk of improper measurement when tank-mixing different products. Onmark can help mitigate many of the challenges companies face in managing weeds, including keeping up with customer demand while facing labor shortages, public concerns with glyphosate, and getting control on tough-to-control weeds.

Choosing the right solution or combination of solutions to keep your customers' landscapes weed-free can be complex. However, by understanding how these solutions work individually and what your customers' expectations are, you can select the solution that works best for you.

TypeFast KnockdownPre-emergentPost-emergent
2,4-DSelective (Broadleaf)XX
Cheetah Pro®Non-selectiveXX
Specticle G®Non-selectiveNAX

Onmark® is a registered trademark of Rainbow Ecoscience. Roundup® and Monsanto® are registered trademarks of Monsanto Technology LLC (Bayer Aktiengesellschaft). Specticle G® is a registered trademark of Bayer Aktiengesellschaft. Scythe® is a registered trademark of GOWAN COMPANY, L.L.C.. Surmise Pro® is a registered trademark of Albaugh, LLC.. Cheetah Pro® is a registered trademark of Nufarm Americas Inc. Finale® is a registered trademark of BASF SE. Snapshot® is a registered trademark of CORTEVA AGRISCIENCE LLC. Sureguard® is a registered trademark of VALENT U.S.A. LLC.