NH Overseed Advice

[dhou]

Hi All,

I've searched within these forums for advice regarding overseeding and the what to do after, but have to admit I am still a bit unsure based on where I am in the process. I understand that overseeding is not generally accepted on aroundtheyard as particularly a successful practice, but a full renovation was not in the cards. Here is what I have done thus far:

* On 9/14/2022 - Seed down with mix of TTTF and KGB
* Followed the "Steps to Overseeding" watering schedule on aroundtheyard
* On 10/5/22 Starter fertilizer (23-23-3; 6 slow release N)
* Today 10/16 - New seedling a little over 2 inches.

We are past our "average" first frost in NH, but no actual frost in my area yet. Weather has remained fairly warm, 60s in the days 40s in the evenings and grass is definitely still growing. I have not mowed and was planning on doing my first once the seedlings reach 2.5-3 inches as suggested. 10/20 (later this week) will be 4 weeks past the average first frost date - marker for stoppage of top growth.

I am not sure how to fit the "Fall Nitrogen Regimen" discussion to my yard. From some of the older threads, it looks like I should be able to start applying 0.5 lbs/K of Nitrogen now, but I'm thinking since we are past the average frost date and close to stoppage date of top growth, this may not recommended? Should I not fertilize any more, proceed with mowing plan when seedlings reach 2.5-3 inches and wait to just apply the winterizing application of urea?

Thanks for any advice that folks are willing to provide. I'm planning on getting some soil samples in the spring and coming back here for more specific amendment recommendations!

[turf_toes]

No one here says overseeding won’t work. So I’m not sure what you mean by that.

Overseeding is fine, depending on your expectations. Though generally there is some research indicating seeding KBG into a Rye lawn won’t be successful.

[dhou]

No one here says overseeding won’t work. So I’m not sure what you mean by that.

Overseeding is fine, depending on your expectations.

My apologies if my comment was over-stated. It seemed to me from reading over the years that if a renovation is possible, it was significantly preferred to over-seeding. That was all I meant, no disrespect or anything.

Any help or suggestions regarding my question regarding fertilizing/nitrogen regimen?

[turf_toes]

No need to apologize. I wanted to be sure to make it clear that over seeding is actually a common and useful practice. It’s not frowned upon here.

Have you read the plan? The reason I ask is if my recollection is correct, you’re far too late in the season to begin thinking about how plan will work in your location.

You’re past your first frost date. The plan doesn’t hinge on the actual first frost. It’s based on an average first frost date. I’d suggest rereading it.

Mid-Fall/"The Pause"
You may wonder why I use the average first-frost date as a planning marker. After all, frost does not stop grass growth. That's all true, but first-frost date tends to precede the stoppage of top-growth in the lawn by 3-4 weeks. When the first-frost occurs in your area, you want to let the grass slow down the top-growth naturally -- continued Urea or AS treatments will force continued growth. I call the period of natural slowdown and stoppage of growth "The Pause". During this period, no Nitrogen applications should be made. The grass will follow its natural progression to stoppage of growth. Continuing your Nitrogen apps through "The Pause" period may cause tender new growth to occur, which may increase the likelihood of winter damage.

viewtopic.php?f=4&t=15109#p205389

[dhou]

Thanks turf_toes,

Ive read the plan, but clearly am still a bit confused by so I just re-read it again as you suggested!

Yes, Andy says the plan is based on average first frost date - but to also use eyes and boots on the ground data. It has been a warmer than typical fall here and weather has been in the 50-60s during the day and high 30s to 40s in the evening. Looks like we have a predicted night temp low of 33 10/20, followed by 30s-40s in the evening into next week. We have not had a frost in my area yet. I was not sure if this was atypically warm enough that I could get away with perhaps one or two apps of N depending on where along the curve we are to be in "the Pause".

I could otherwise assume that I am currently in "the Pause" based on average first frost date. Then I should not fertilize, but will slowly mow down by 1/3 until my target height. When growth seems to have stopped, then I should apply 1 lb/K of Nitrogen using 46-0-0 urea as my winterizer app and call it quits for the year. This is probably the safest route.

[Masbustelo]

I would concur, no more N until the final drop. Perhaps go with a half rate at that time. Then maybe some light milorganite drops as needed in spring. Then a normal app about May 15th and you'll be back on schedule.

[andy10917]

Yes. Even if you had a 90 degree day, that is not indicative that it will be 90 degrees (or even 80 degrees) in 3-4 weeks (the length of the Pause). The best indicator is the long-term average, and that's what the Average First Frost Date is. It is the best predictor of the most likely time when to let the grass move along on its own schedule.

[dhou]

Thanks everyone - Appreciate the confirmation and feedback!