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Hi all,

I'm in need of some assistance and guidance.

I have a section of lawn that is 50% weed, in patchy areas with some decent grass, and some full sections of weed. My goal was to kill off the weeds with selective herbicide and then power-seed the entire area say 5 days after core aeration. I applied 2-4 D a few weeks ago and then tenacity maybe 10 days ago to get ahead of the weeds I was trying to kill. Core aeration was two days ago. I was hoping to power-seed tomorrow.

I have mostly one weed left that is proving tough to kill. While some of it has been eradicated with the selective herbicides I still have large sections that are relatively full and I suspect will interfere with new grass germination and growth.

So, here are my options as I see them:

1. Hope that the weeds are on their way our (tenacity can take 3 weeks to knock off some weeds) and proceed with the power-seed hoping that at the time of germination a bulk of the remaining weeds will be gone.

2. Glyphosate the heavily weeded sections, avoiding the better grassy sections and wait until next week (5 days later) and then power-seed.

3. Enlist the help of you and come up with a better option that will better my chances for success.

I'd hate to kill off everything as the grassy areas are not too bad and I think salvageable.

Thoughts?

Bryan

Bryan,

Your approach has some good aspects, but also some less-than-good aspects (some may even say flaws), too.

The good things include the fact that you're addressing the weeds, are doing this early enough in the season to have a chance of success, and are soliciting advice.

Many folks here have found that core aeration brings up just as many weed seeds as it helps reduce compaction. Actually, unless you have a significant mechanical compaction problem, such as caused by driving heavy equipment on the lawn, or heavy foot traffic (the area around a pitcher's mound or home plate), core aeration tends to do more harm than good due to bringing up weed seeds. Slit-seeding (if that's what I understand you to mean by power-seeding) has the same problem.

Take a look at the Triangle Approach article: https://aroundtheyard.com/index.php?opt ... Itemid=117

Regarding the weed that is surviving your 2,4-D and Tenacity, it may be necessary to apply glyphosate to get rid of that one.

Be sure when applying any herbicides, you check to see if there is a residual effect that can diminish seed germination. I know there is a recommended wait time for 2,4-D before seeding, but I don't remember what it is; probably just 2-4 weeks or so. It is safe to seed after a glyphosate application as soon as the glyphosate is dry, but you need to be wary of products that include not just glyphosate, but another active ingredient (such as diquat) that may not allow immediate seeding.

Lastly, in all honesty, when doing more seeding, the most important of the weeds to get rid of is the one that you can't eliminate with selective herbicides (your unknown weed) as that is the one that will be hardest to get rid of after your new grass has germinated. Can you post a picture of the resistant weed? Some folks here are excellent at weed ID (TimmyG comes to mind.)

Thanks for the information.
I'm hopeful with the application of Tenacity that I may be okay stirring up a few weed seeds with the aeration and slit-seeding.
Attached are two pics of the weed in mind. Same weeds, just different light.

Thanks for the help in ID.

With zero first-hand experience, I don't want to be the first one to suggest Japanese Stiltgrass, but...

Do you have an areas of the weed that haven't been mowed?

I decided to just hit it all with glyphosate a few days ago. Most all of it is dead, as is any grass, but such is life.

I scalped the lawn today and then blew everything clear with the big leaf blower.

I’ll wait another two days and then Powerseed the entire 1/3 acre. I figure I’ll need about 90 lbs of sun and shade mix. Does this sound right, or should I go a bit heavier?

Should I blanket with tenacity after powerseeding?

All help is appreciated.

Thanks

Bryan