What is this grassy weed?

Question

I live in the Nashville, TN area, and I've noticed a particular type of grassy weed starting to pop up in my lawn, now that it's March. I'd like to identify it so that I can learn how to prevent it from spreading further.

It's a lighter green color than the rest of my lawn, and its leaf blades are flat and approximately double the width of my other grass. The stem is round near the bottom, with multiple leaves branching from the sides as it goes up. It has what looks like a small purple taproot with smaller roots coming out of it.

I apologize for the quality of these photos (especially the third one!), as I couldn't gauge how clear they were in the sunlight on my phone. If they don't help, I'll try to get better photos to replace these.

A small patch of this weed:

A young plant with a single stem:

A mature clump of this weed (sorry for the blurriness):

We had a lot of dallisgrass last year, so I'm curious if this is young dallisgrass, which I understand is a bit easier to treat than after its been around for a few weeks.

Answer 1

Sure looks like Dallisgrass. I'd use ROUNDUP or a glyphosate product VERY CAREFULLY...get a sheet of saranwrap to surround the clump, then paint with a little brush the glyphosate on a few of the blades of this grass. Doesn't have to be much or on all of the leaves. For each bunch of Dallisgrass use a new piece of saranwrap as a skirt to protect your lawn. Glyphosate is then transported to the roots to kill the roots. If any gets on the good grass it will kill it as well. If that happens, allow it to die and reseed asap. I don't like pre and post emergent chemicals but I've not had much experience with your southern lawns and this dallisgrass. Allow the dallisgrass to completely die and then you can pull it up. This takes up to 3 weeks for complete kill. Do not mow for a few days.

Get your lawn as healthy and vigorous as possible, mow short and do not allow that Dallisgrass to go to seed! Use the glyphosate when your lawn and weeds are vigorously growing. That will ensure the best root kill.

My next therapy would be pre-emergent products. Follow the directions to the letter. Re read at least 5X (this is what we were taught for pesticide licensing).

Count on doing this every other month for a few years. Add the pre emergent herbicide once a year and you might just get this in control.