Have weeds taken possession of your customers’ ornamental beds? Good news. Fall is an excellent time for managing ornamental bed weeds that have taken over, especially broadleaf weeds.

Broadleaf herbicide uptake increases in the fall. Weeds concentrate on storing energy in the root system instead of top growth, which brings nutrients down into that system. After a herbicide application in the fall, weeds bring the herbicide’s chemistry along with the nutrients down into the root system. This increases herbicide uptake and allows for a more complete kill of the weed. 

One thing to consider when using herbicides in landscape beds is whether you can apply an “over the top” herbicide or a non-selective to manage weeds already present. “Over the top” herbicides are a material applied over the planting, which controls undesired weeds without harming desired plant material. Make sure to read the label to confirm that the specific plant material is tolerant when applying “over the top” herbicides. 

When using glyphosate to manage landscape bed weeds, do so in a targeted manner. Some additives help glyphosate work better on stubborn or resistant weeds, but it depends on the weed type. 

Consider using adjuvants when using liquid broadleaf herbicides for control. Spray adjuvants make a significant difference in efficacy, which leads to customer satisfaction. When customer retention frequently hinges on how you finish the season, additions like spray adjuvants can make a big impact.

Besides using herbicides to control existing weeds, you can also apply them to get ahead of some weeds. Applying pre-emergents to landscape beds in the fall allows you to control winter annual weeds, like hairy bittercress, before they have a chance to germinate. Hairy bittercress is a significant problem in landscapes and lawns. Since it’s one of the first weeds to flower in the spring, it often becomes the source of many angry phone calls and unnecessary service calls. Putting a pre-emergent down in the fall mitigates exposure to many other problematic weeds and the issues that they create.

Whether you’re applying liquid or granular pre-emergent applications, make sure to find out if the products work better underneath or on top of the mulch. Under the mulch, isoxaben, trifluralin, and oryzalin tend to work better. When applied on top, flumioxazin and oxadiazon tend to work better.

Never apply granular pre-emergent when desired plant leaves are wet. Also, try to avoid contact with ornamental plant foliage when using most liquid pre-emergents. Remember to read the label to make sure desired plant material is safe for the application of specific active ingredients and for any other restrictions.

There is a plethora of pre and post-emergent herbicide options. Speak with your Advanced Turf sales representative to find out what will work best for your situations.