2,4-d only works on broadleaf plants, not on grasses. You need a grass killer, which, of course, is a problem when the grassy weed is in your grass. You'd be surprised how much you can dig out in an afternoon. You may have some bare spots when you're finished, but it's getting closer to seeding time in MA. Make this an August project and then seed it.

Thank you for the response. Sounds like only plan to get rid of this and not kill other grass is, pull what I can in August, overseed in September and apply pre-emergent in the spring?

There are some herbicides that work selectively. I don't know what they are, but others here on the forum do. Hang in a little longer.

I haven't actually seen smooth crabgrass in years, but does this look like it to anybody else in its baby form?

Regardless, I'd be very tempted to try Weed B Gon Crabgrass Killer.

I live in Central Mass and have the same smooth crabgrass growing in my lawn. I have been pulling it a few hours a day, a couple of times per week. I am going to spray the thickest infiltration with Image Crabgrass and Weed Killer Concentrate found at the locale Tractor Supply Store. The active ingredients are Sulfentrazone and Quinclorac. My brother-in-law spot sprayed his lawn about a week ago and it did the trick. Warning: The area you spray will turn an orange / yellow. color. It is not suppose to harm the lawn grasses if used properly.

I don't really care if my lawn turns color; I am trying to kill the crabgrass off before it goes to seed.

Products with a high percentage of quinclorac (18%-20%) will work well on grassy weeds. I use Quinclorac 1.5L Select (64oz $65) w/ Methylated Seed Oil (Ag Southern $15 quart)-Crab/Goose/Quack/Grasses. You may have to treat twice but it will kill it. Best to allow 2-3 weeks after treatment before seeding/overseeding so get it down now.

Will