What You Need To Know About Fall Landscape Bed Herbicide Applications

Have weeds overwhelmed your customers’ ornamental beds? Good news. Fall is an excellent time to manage weeds that have taken over ornamental beds, especially broadleaf weeds.

That’s because broadleaf herbicide uptake increases in the fall. Since weeds concentrate on storing energy in their root systems instead of top growth, nutrients are brought down to the roots. After a herbicide application in the fall, weeds will bring the herbicide’s chemistry, along with the nutrients, down into the root system. This increased uptake 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 that are already present. “Over the top” herbicides are applied over the weeds, controlling them without harming desired plants. When choosing an “over the top” herbicide, make sure to read the label to confirm that your desired plants are tolerant.

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 applying liquid broadleaf herbicides. Spray adjuvants make a significant difference in efficacy, which can lead to increased customer satisfaction. When customer retention frequently hinges on how you finish the season, additions like spray adjuvants can make a big impact.

In addition to using herbicides to control existing weeds, you can also apply them to get ahead of them. 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 phone calls and unneeded service requests. Putting a pre-emergent down in the fall mitigates exposure to many other problematic weeds and the issues they create.

Whether you’re applying liquid or granular pre-emergent herbicides, 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-emergents when desired plants’ 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 your desired plants won’t be harmed by your herbicide’s active ingredients and for any other restrictions.

There are a plethora of pre- and post-emergent herbicide options at ATS, so speak with your rep to find out what products will work best for your situation.