Prepping for significant Fall overseeding - TTTF

[redcoat]

Hi everyone,

Grass has struggled through this year, following renovation drama last year (hurricanes right after etc)..

So, I don't think I need a full reno, but there are significant areas that have been weak and sickly throughout, and I've lost patches of even the healthier parts.

What should be aware of to prepare for best chance of success. I'm using a blend of the best TTTF in the recent NTEP trials (Titanium 2LS, Avenger II and Firecracker SLS).

The heat here (Raleigh, NC) is brutal - constant 90+. Doesn't usually cool down until mid-Sept at the earliest. I have good irrigation coverage. Local turf files indicates I should seed Sept. 1 to Oct. 1.

Here are my questions at this point - would really appreciate advice!

1. How does heat affect seed-down date? If it's still 90+F, is it still ok to seed Sept 1 if I have irrigation?
2. I'm assuming I should I lime now, so that it's well worked in by then?
3. When should I start putting down milorganite again (I've stopped for the summer)?
4. I'm assuming I should spot kill weeds with roundup in plenty of time?
5. When is the best time to use BLSC to make sure everything is ready?
6. Should I be afraid of fungus? If so, how best should I prep?
7. When overseeding, what fertilizer / weed preventer approach should I take? Last time I had good success with Starter Fertilizer with Mesotrione.

Many thanks!

David

[andy10917]

David, some of your thinking is too binary (Yes/No, or exact dates). The only person that can calculate the best time for all of the inputs to your lawn is (wait for this!) YOU. You need to concentrate upon learning how to balance all the factors and making an educated decision.

Here are some factors that you should consider:

(1) Heat does not affect germinate per se. Optimally, you want a good 8 weeks after germination of establishment time before first frost date. So, if TTTF is 10-14 days from seed-down to germination, you want 9.5 - 10 weeks between seed-down and frost date. If you have irrigation, a couple of those weeks can be while it is still hot and the sunlight is still strong (the sunlight is already getting weaker).

(2) What did your latest soil test say about Lime?

(3) There's the binary stuff. Lawncare isn't ON/OFF like a light switch. Ease up but don't quit.

(4) You'll probably want to hit weeds twice if using RU. You can seed right after the second app dries.

(5) This is very tricky. Like Milorganite, BLSC should only be applied on days that have names ending in "Y". For times, only after midnight each day and before midnight the next day.

(6) You should always be afraid of fungus. No fungicides are recommended at seed-down time.

(7) Again, fertilizer depends on your soil test results. Do they say you need Phosphorus? For weed prevention, either a Tenacity app at seed-down or the Starter with Mesotrione (same as Tenacity) works. Repeat at 30 days.

Why is the current grass still struggling? Did you try the Philes Phertilizer regimen for new grass?

[PW405]

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Why is the current grass still struggling? Did you try the Philes Phertilizer regimen for new grass?

Philes Phertilizer regimen? I would be interested in learning more about this.

[andy10917]

Then you might want to try the Search feature....

[kevreh]

Redcoat-

Not sure about you but just north, up here in northern VA, were starting to get into moderate temps (80's) for highs and a decent amount of rain, at least 1-2x per week. As a result my lawn is starting to green up and I need to go back to mowing every 5 days. In July, otoh, I watered my lawn just enough to keep it from completely going dormant, and mowed every 10-14 days. My point is if this is what your seeing dropping milo is fine. But if its not really growing due to heat and lack of moisture then I'd wait.

[redcoat]

Hi Andy,

See, binary is what you get being a computer programmer I'm trying to shake that when it comes to my yard!

(1) Heat does not affect germinate per se. Optimally, you want a good 8 weeks after germination of establishment time before first frost date. So, if TTTF is 10-14 days from seed-down to germination, you want 9.5 - 10 weeks between seed-down and frost date. If you have irrigation, a couple of those weeks can be while it is still hot and the sunlight is still strong (the sunlight is already getting weaker).

Ok, great. I'm nervous about my tender seedlings hitting 90F temps when they emerge, but I have some soil moist which I'll use.

(2) What did your latest soil test say about Lime?

Every 90 days, yes.

(3) There's the binary stuff. Lawncare isn't ON/OFF like a light switch. Ease up but don't quit.

Hmmm, even in the transition zone with full sun and blazing 90+F for weeks at a time?

(5) This is very tricky. Like Milorganite, BLSC should only be applied on days that have names ending in "Y". For times, only after midnight each day and before midnight the next day.

Ha! Point taken.

(6) You should always be afraid of fungus. No fungicides are recommended at seed-down time.

I think I was hit with quite a bit this year. I need to read up on approaches for next year.

(7) Again, fertilizer depends on your soil test results. Do they say you need Phosphorus? For weed prevention, either a Tenacity app at seed-down or the Starter with Mesotrione (same as Tenacity) works. Repeat at 30 days.

No - P was fine. Ok, I'll go with Starter with Mesotrione again this year. How soon after germination should I start on fall nitrogen regime?

Why is the current grass still struggling? Did you try the Philes Phertilizer regimen for new grass?

This is a good question. I have no idea, tbh. Some areas did well. But several just didn't grow higher than about 2 inches and looked weak and sickly all year.

Appreciate the advice!

cheers

David

[STL]

Propiconazole is labeled for seedlings once they get 2-3 leaves iirc. Check the label though. Generally, you want to wait until sprout and pout is over and vertical growth kicks in for more fert, roughly 30 days post germination. It allows the plants to focus growth on roots Vs top growth first. Some may start earlier though.

[redcoat]

Thanks, STL!

This is my first time worrying about fungus. Is it generally best to be proactive or reactive when it comes to fungus in the Fall? My impression was June timeframe is when it's at it's worst?

[STL]

You're basically right that summer is typically disease time, but with the amount of water for germination and weather that's still warm, it definitely could be an issue. It's always best to be proactive with managing disease. It doesn't need to be chemical fungicides though. Serenade is an option. It really depends on the situation and how you want to manage your lawn.

[northeastlawn]

Serenade is an option. It really depends on the situation and how you want to manage your lawn.

2nd that!

It may be the cooler summer and wetter spring; but I started applying serenade every other week this year in May and I haven't seen a trace of fungus so far in my hell strips. Rust destroyed the front grass last year. It may also be because the grass that survived is two years old.

But I am a serenade believer now and will also apply the other recommended prevetative treatments next year on the new KBG backyard, fingers crossed.

[fall50]

What should be aware of to prepare for best chance of success. I'm using a blend of the best TTTF in the recent NTEP trials (Titanium 2LS, Avenger II and Firecracker SLS).

Where did you purchase the seed from.

[redcoat]

@STL - what's the best approach to use Serenade in the context of an overseed?

@fall50 - Southern Seeds, in Middlesex, NC. They're struggling to get it in in time this year, so I found a different blend locally that looks good - XtremeGreen, Raptor III, Firecracker SLS.

[redcoat]

I'm also trying to understand the best way to prep the lawn...?

I have some area that appear dead, so need to clear the dead grass. Would a slit seeder do it all in one? Should I find someone to rake the yard first? How long do people recommend mowing TTTF in preparation for overseeding?

[STL]

@STL - what's the best approach to use Serenade in the context of an overseed?

For the record, I haven't used serenade on an overseed before. But it shouldn't change much from use on an established lawn, other than you probably want to be mindful of foot traffic and you're going in knowing that fungal pressure may be high due to watering. I'd probably do a heavy dose every week or two and start as soon as possible before the overseed. Like its 'regular' use, you're still going to need to read the lawn and be prepared to adjust depending on conditions and what you see.

[Marinegrunt]

You don't have to remove the dead grass. If there are big patches of dead grass you might want to scalp those areas with the mower. I would definitely drop the height of cut a little lower than summer cutting height though. Maybe start now and slowly drop it to give the grass time to adjust. What height are currently mowing at?

Using a slit seeder will introduce more weed seed but that's your call. Once you water the seed should drop down to the soil even if you don't slit seed. If there are a lot of dead spots you could incorporate peat moss as a top dressing too. It will help hold in moisture.

Others will give you better tips than what I can offer.

Good luck!

[redcoat]

Thanks!

Currently cutting at 3".

How would a slit seeder introduce more weed seed - just by disturbing the soil? I'm planning to use the starter + Mesotrione and then keep on top of pre-emergent to guard against as many weeds as possible.

[Marinegrunt]

You're exactly right. Anytime we disturb the soil it will cause the weed seeds that are too deep in the soil to sprout to move around and some make it to the surface. The Mesotrione will help but the more seeds the higher the risk for sprouting weeds. Most weeds are easy to kill but certain types are very difficult to get rid of. That's a big reason to minimize all the weeds we can.

All grass seed needs is good seed to soil contact. Well, water, sun, etc too. It doesn't have to be buried. It really comes down to what you want to do. I'm doing a complete reno this fall. I know slit seeding isn't recommended because of weed seed but I'm considering it because of all of my sloped areas. I'm worried about washouts and slit seeding would get the seed in the ground hopefully saving my seed. I haven't made my mind up yet. I might wait and look at the 7-10 forecast. If I had a flat lawn I wouldn't even consider it. We just have to weigh the odds depending on our situation. I don't see how slit seeding when over seeding would make a difference. It might get you better seed to soil contact but I think you'd get it anyways. I can't answer that for sure tho so make others comment on it before deciding. If you're set on slit seeding you can deal with any added weeds later. That's my plan. The tenanicity I'm using and Mesotrione will help.

[probasesteal]

I tried slit-seeding 2x (before I learned better). If your lawn is perfectly flat with little to no debris, it can help. The Tenacity helps, but is a better post-emergent than pre-emergent.
Think of it Tenacity like wearing a condom with someone who you know has an STD vs abstinence. You know your soil is full of weed seeds and Tenacity will help with some of that, but not disturbing the soil is a better option.
I would just lower HOC as mentioned above and gently try to rake the thatch in the dead areas. And before you call me out on it, I know raking also disturbs the soil to some degree.

[STL]

I've never slit seeded but I have looked into it and read about it, so take this for what it's worth. Slit seeding is not necessary in most instances and can over complicate things with regard contributing to weed pressure and requiring equipment (time and expense). Marine grunt's hill-washout example sounds like a situation where it could be valuable. The majority of folks on this forum don't slit seed and have great results. My take is it's one of those things where sometimes people think more is better, but that's not always the case with lawn care.

[redcoat]

Ok, thanks for the feedback (and analogies ).

Similar fear with detacher set high so it just exposes dirt?