Minimize pricey labor with an economical herbicide plan
Lawn care operators challenged with managing weeds in ornamental beds can save money and satisfy customers by using an integrated weed management program that includes herbicides and mulch. While hand-weeding always will be important to weed management, an integrated herbicide program can minimize labor greatly.
Proper herbicide applications can provide weed control for two months or longer, creating consistently clean landscapes. Mulch gives beds an additional layer of weed prevention.
However, developing a herbicide program can be challenging because of ornamental selection, placement within a landscape bed, the presence and growth of weeds, and germination expectations. Advance consideration of which chemical and mulch techniques are compatible with a landscape can cut traditional hand-weeding labor costs in half.
Before selecting an herbicide program, determine whether an herbicide can be used safely with the area’s mixture of woody ornamentals and herbaceous bedding plants. Determine whether weeds can be managed more easily before germination using a preemergent herbicide or whether weed control can be handled effectively using a postemergent herbicide. Some landscapes may need both.
Generally, woody ornamentals are more tolerant of broad-spectrum herbicides, so there’s a greater number of preemergent and postemergent herbicide options available for use on these plants. Only a few herbicides are labeled for use on sensitive herbaceous species, particularly annual flowers, so applicators should know about the safety of the product they intend to use.
Because bedding plant species vary as much in herbicide tolerance as they do in color, form and plant vigor, confirm plant safety by checking herbicide labels and conferring with local extension specialists and herbicide company representatives when developing a plan.
Identifying weed types or those likely to germinate in the landscape to determine which type of herbicide to apply. Any combination of broadleaf, grassy and sedge weeds can be problematic.
Weeds compete for nutrients and water, but they can be related closely to many of the annual and perennial bedding plants, so choosing an herbicide that kills weeds — while being safe on desired plants — is more difficult.
Herbicide labels list weed types controlled by the active ingredients’ modes of action or behaviors in the plant. Some herbicides are effective on broadleaf weeds but not on sedges, while others control two weed types but not all three. Therefore, proper weed identification is an important first step to ensure desired weed-control results.
Look for opportunities to use herbicide combinations, commonly in granular formulations, to increase the spectrum of control. When using a sprayable formulation, for example, check the label to see whether mixing multiple products to control a greater number of weeds with one application is recommended.
The most effective and economical weed control method is prevention. Preemergent herbicides help prevent seeds from germinating but are not active on established weeds. They’re commonly used to prevent annual grasses and broadleaf weeds.
Before you can prevent growth, you must eliminate weeds that have germinated. Hand-weeding or postemergent herbicide spot-spray treatments are recommended before making new or repeat preemergent applications.
Preemergent herbicides are available in granular and liquid formulations. Granular formulations tend to be less damaging when used on bedding plants. Uniform applications should be made when plant foliage is dry to prevent the herbicide from binding to foliage. The application should be timed before seeds germinate and where irrigation is available, or when rainfall is expected within a few days of the application. This is important because water must carry the herbicide into the soil where it creates a barrier to weed germination.
Once an application is made, control typically lasts two months. An herbicide’s activity length in a specific region can be monitored efficiently when lawn care managers return to customers within a five- to eight-week cycle.
Once an herbicide program is put into action, it’s important to manage weeds in nearby turf to prevent depositing weed seed and vegetative parts of weeds from moving into landscape areas. Weed management in lawns and landscapes should work in concert to eliminate a customer’s overall weed problem.
With awareness and experience, you’ll become more familiar with the herbicide products available for weed control and how to develop a plan. Use caution when applying herbicides and always read and follow chemical labels and manufacturer recommendations.
KALMOWITZ
is a market and technical specialist for BASF Professional Turf & Ornamentals.
