Post-Emergent Herbicides

About Post Emergent Herbicides

Post emergent herbicides work well in late spring, when weeds are small, young, and actively growing. Smaller weeds are easier to control, and if they’re actively growing, they will more effectively take up and move the product through to the roots. They also work very well in the fall, when weeds are preparing for winter.

Choosing A Post Emergent Herbicide

There are many options and choices when it comes to post emergent herbicides, so it is important to pay close attention to the specific formula.

1. Decide whether you want a liquid or a granular product.

• Liquid formulas must be diluted and applied with a hand pump sprayer, or the package may come with a hose end sprayer attachment.
• Granular formulas are applied with a drop or broadcast spreader.

2. Check the product label to see if it is a selective herbicide, which will only control the plants listed on the label, or non-selective, which will kill any plant it comes in contact with, including your lawn or other desirable plants. This will also help you determine if the product you choose will work against your weeds.

3. Many products are formulated to work on certain types of grass. Read the label carefully to check if your type of grass is listed on the label. Otherwise, you could risk injuring or killing your grass instead of the targeted weeds.

How To Use Post-Emergent Herbicides

Post emergent herbicides can be very successful at controlling weeds when applied carefully and with proper timing. Here are things to keep in mind for effective post emergent weed control.

• Apply when temperatures are below 85 degrees. Hot temperatures mixed with the product could cause injury to your lawn.
• Do not water in post emergent products, and if rain is the forecast within 24 hours of application, delay application. Rain will wash away the product before it is able to reach maximum efficacy.
• Do not apply to wet or damp grass
• Do not mow before application. Allowing the weeds to grow a bit will let the product have maximum contact with the leaves for good absorption. Do not mow for a few days after application.
• Weeds that are under stress from drought are harder to control, and herbicides are less effective. Consider waiting till your lawn and weeds recover from drought before treating.
• The morning is often the best time to apply a post emergent herbicide, especially a liquid formula, because wind is generally lower and plants are able to metabolize the product better.