Bayer is proud to sponsor the first-of-its-kind weed management special issue of Nursery Management and we are excited to examine the important trends for the industry that come out of this report. This year has brought many changes and challenges, especially related to the ongoing scarcity of available nursery laborers and the increasing costs associated with that labor. With these realities claiming center stage, it may be tempting to skimp on overall pest control. However, in an industry that is all about quality, this is not an effective or economical long-term solution as pest damage and reduction in plant quality can have long-term negative impacts.

Tackle complex weed challenges

When allowed to flower, some weed species are capable of producing thousands of seeds per square foot. Weeds are expensive to control, especially after they emerge. In fact, on many nursery operations, herbicides account for nearly 50 percent of pest management costs. However, the greatest cost of weeds is the cost of neglect. Weeds that are left unmanaged or treated ineffectively cause significant upticks in costs for labor required to scout and hand-weed. Growers must also consider the ever-changing inventory of plants and the potential for introducing new and potentially invasive weed species. Fortunately, the use of a preemergence herbicide to preventively control weeds before they germinate can result in dramatic cost savings over the course of the growing season.

Controlling weeds at the source is the key to success

Starting clean and staying weed-free is the best approach any nursery grower can take to be successful. Following strict sanitation guidelines to maintain a clean environment minimizes opportunities for introducing pests, diseases and weeds. Taking the time to install physical barriers (such as ground cloth) to reduce exposure to the soil beneath containerized plants minimizes the potential for weed contamination. Preemergence herbicides can be applied around adjacent buildings, on gravel roadways and in plant holding areas to effectively control weeds.

This approach minimizes the potential for weed outbreaks reducing labor costs for hand weeding and post emergence herbicide applications. In fact, a single application of Marengo® herbicide at the high labeled rate can provide weed control for up to eight months. Every time a grower has to make a pesticide application there is site preparation, application prep (i.e. preparing equipment and product mixing), application of the treatment and then any necessary clean up (equipment, disposal, etc.). Avoiding more frequent applications saves time and money and highlights the value of using Marengo® for long-lasting weed control.

Innovative weed management solutions

Ultimately, when it comes to managing weeds, growers are first and foremost looking for solutions with good performance and crop safety. At Bayer, we have several solutions that help growers effectively control weeds in the nursery. Marengo® preemergence herbicide demonstrates excellent crop safety and provides up to eight months of residual control of more than 90 weeds with a single application. Marengo® G preemergence herbicide is labeled for use on 266 plant species and provides up to five months of residual control of over 90 weeds. Ronstar® G preemergence herbicide offers exceptional root safety and is ideal for use on newly transplanted ornamentals and liners. It is labeled for use on more than 250 ornamental species with strong performance on several difficult-to-control weeds. And for postemergence weed control, Roundup PROMAX® and Roundup QuikPRO® are great options for putting a stop to more than 200 types of grassy and broadleaf weeds. Growers can learn more about these and other innovative solutions for pest control in nurseries by visiting

Last, but not least, thank you Nursery Management for sharing this important weed management special issue. We look forward to being part of this report for years to come.


Steve Larson Nursery & Greenhouse Crop Specialist – Southwest US, Ornamentals, Bayer

Aaron Palmateer, Ph.D. Senior Technical Service Representative, Ornamentals, Bayer

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