As February crosses into March, now is the time to fend off lawn weeds. It is not too early. A healthy stand of turf is the best protection against competition against weeds. But if you are starting with a less than prefect stand of grass and weeds have been a problem in the past, now is the time for prevention with pre-emergent herbicide.
The application of a pre-emergent herbicide will help control the seeds in the soil before they have a chance to germinate. You will want to make two applications about 60 days apart. The first application should be around the period of February 15 to March 1 or when the temperature is 70 degrees or above for a few days in a row. Please note that it is too early to apply fertilizer since the lawn is not ready to take it up. The second application can be applied about 60 days later and can be made as a stand-along application or with a weed and feed product.
Identifying Lawn Weeds
It is helpful to know which kinds of weeds you’re fighting. Lawn weeds fall into three categories:-
- broadleaf – where the veins on the back resemble a webbing pattern
- sedge – which resembles a 4th of July sparkler with triangular “stems”, and
- grassy weeds – with the veins on the back running parallel to one another.
Readily Available Herbicides
Herbicides that are the most readily available to home owners are products that contain atrazine or pendimethalin. Atrazine will mainly control broadleaf weeds while pendimethalin will control grassy weeds and some broadleaf weeds. But again, please be mindful of a “weed and feed” product. Fertilizer should not be applied in our zone of 9A until the middle of April. This means that the second application of pre-emergent herbicide could coincide with a fertilizer application.
For more questions, please reach out to the extension office and ask to speak with a Master Gardener Volunteer.
(This post has been researched and provided by Master Gardener, Walter Bryant.)