# Overseed rate with custom mix



## MichiganGreen (Aug 7, 2018)

So the time is fast approaching to drop all this...Total of 17,000 sq ft.

I'm going to be using this:
https://www.homedepot.com/tool-truck-rental/Overseeder/TS-20HD/

EDIT: I think I'll go with this instead - extra money but this is self propelled and I don't think the above one from HD is. I have a hill in the back, and I think I'll thank myself.
https://chetsrentall.com/product/power-rake/ (Bill Goat Self Propelled Overseeder, not sure why it's called power rake in the URL)

I have:
50 lbs GCI TTTF , which advises 4-7 lbs/1,000sqft with 75% cover which feels about right in my situation. No major bare spots just thin to be sure.
https://www.gciturfacademy.com/product/gci-premium-turf-type-fescue-blend-50-lb/

25 lbs Cornell Classic, which advises 3 lbs/1,000 sqft , as the only option. Just calls it the "seeding rate" which I assume means for bare soil?
https://www.preferredseed.com/detail/index.cfm?nPID=1

I plan on mixing it all into one big mix and aerating and then renting the above seeder I linked to HD.

Question is, once I mix them all together how do I decide on a ratio per 1,000sqft. Do I just meet in the middle? I feel like I need a bit of math assistance.

PS: Do these ratios sound accurate - particularly the 4-7 pounds on the GCI - seems like a lot?

Thanks in advance!


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## g-man (Jun 15, 2017)

Tttf is a larger seed, so it goes at a higher lb rate.


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## Turfguy93 (Aug 30, 2017)

Just mix the seed and apply all of it evenly over the 17000 sq ft. That willl get you about 4,5 lbs per thousand which is about perfect


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## MichiganGreen (Aug 7, 2018)

g-man said:


> Tttf is a larger seed, so it goes at a higher lb rate.


Ahhh so am I just overthinking? It's the same setting for all...will provide the different rate by way of the actual seed weight itself?


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## MichiganGreen (Aug 7, 2018)

Turfguy93 said:


> Just mix the seed and apply all of it evenly over the 17000 sq ft. That willl get you about 4,5 lbs per thousand which is about perfect


Yeah I was overthinking...I think. So if i set my spreader to X setting for all, you like the 4 or 5 pound setting for example...but Cornell classic only advises 3 pounds per 1k. Am I missing something? Wouldn't be surprised.


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## Tsmith (Aug 11, 2017)

What type of seed is Cornell Classic?

If it's TTTF I would just drop it same as the other or maybe a bit less. If it's a different type and I'm guessing it is based on the rate bc that would be light for TTTF then I would drop separately and determine what percentage of each you want and subtract accordingly.

For instance that 3lbs is prob if you were using it for 100% of the seed ur dropping which you won't be so if you want 75% of the TTTF and 25% of the Cornell Classic you will need to adjust but I would highly recommend you drop them separately otherwise you won't get an even spread of the mix you want.


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## Turfguy93 (Aug 30, 2017)

If you evenly mix the 2 seeds together the rate should work out fine


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## MichiganGreen (Aug 7, 2018)

Copied over from the page below:

Seeding Rate: 3 lbs. per 1,000 sq.ft.

65% High quality low cut improved Kentucky Bluegrasses

20% Improved Perennial Ryegrass

15% Firefly Hard Fescue


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## MichiganGreen (Aug 7, 2018)

Good point on an even mix though. I'll spread twice.


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## Tsmith (Aug 11, 2017)

MichiganGreen said:


> Copied over from the page below:
> 
> Seeding Rate: 3 lbs. per 1,000 sq.ft.
> 
> ...


I don't know about Rye or Hard Fescue seeds but Bluegrass (KBG) seeds are a lot smaller (like sesame seeds) than TTTF seeds so you wouldn't want to drop them at 7lbs / k.


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## MichiganGreen (Aug 7, 2018)

Tsmith said:


> MichiganGreen said:
> 
> 
> > Copied over from the page below:
> ...


If I'm doing them separately, should i drop less than the recommended knowing I'm mixing in another type?


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## Green (Dec 24, 2017)

MichiganGreen said:


> If I'm doing them separately, should i drop less than the recommended knowing I'm mixing in another type?


It can get tricky if you think too hard and try to make the math work. It never seems to work right.

So, the solution is to first figure out the percent TTTF seed (not grass) you want to use. Let's use 50 because it's easy to explain...

Full/heavy overseed rate is 6-7 lbs for TTTF. 50 percent of 6 is 3 lbs.

But you still need 50 percent of seed from the other mix, the fine fescue, PR, KBG mix. Find the heavy overseed rate for that mix and multiply it by 0.5 also. If normal heavy overseed rate is, say, 3 lbs (not sure if that's right, just an example but I think it's close), you'd use 1.5.

Apply seperately. Or, you can mix the two and add the weights. 3+1.5=4.5
If mixed, you would apply 4.5 lbs per thousand square feet. Again, just a rough example. Don't necessarily use these exact numbers.

Also, if you don't want 50 percent, use a different multiplier, like 0.6 for 60 percent.


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## Tsmith (Aug 11, 2017)

MichiganGreen said:


> Tsmith said:
> 
> 
> > MichiganGreen said:
> ...


Yes because the recommended rate is if that's all you were dropping meaning your seed would be 100% of just the one but since that's not your plan you need to determine percentages.

For instance when I did my previous TTTF / KBG mix I went with a 70 / 30 split so I did 70% of the recommended for a TTTF lawn and 30% for a recommended KBG lawn.


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## MichiganGreen (Aug 7, 2018)

Man this is wild. Thanks all. So for 17k of grass do I even have enough...should i pick up more.? The 50 pounder recommends 4-7lbs per 1k and the 25 pounder recommends 3 per 1k


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## MichiganGreen (Aug 7, 2018)

I did some math the best I could and came to needing 51 pounds of the TTTF (I have 50 so close enough), and 35 pounds of the Cornell Classic - So I need to buy 10 more pounds. Can somebody please help verify this?

To confirm - 17,000 sq ft total
GCI TTTF - 4-7lbs / 1,000 sq ft - 75% of mix
Cornell Classic - 3lbs / 1,000 sq. ft - 25% of mix

Does getting 10 more the Cornell classic? I'm bad with math and this is the best I can do - With all this money I don't want to drop the ball. Many thanks.

EDIT: If I added 10 more pounds of Cornell Classic that would change my mix - no longer 75/25, ugh....help....I have a headache.


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## Powhatan (Dec 15, 2017)

Might not be the correct traditional custom formulation approach, but this is what I would use in this situation.

Realize even with a perfect formulated #/M number, that moving a spreader over an area the actual #/M applied to the ground will not be perfect exact for each M area, it's a desired target.

Start with a desired seeding rate (higher = new lawn, lower = thin/overseed lawn) for the variety being put down, then reduce to the % amount you want to apply.

Example:

5 lb x 17 M x .75 = 64 lb
3 lb x 17 M x .25 = 13 lb

64 lb + 13 lb = 77 lb / 17 M x 1 M = 4.5#/M spreader application rate - no half rate setting on spreader? you'll need to decide the closest higher or lower whole number to use.


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## MichiganGreen (Aug 7, 2018)

Powhatan said:


> Might not be the correct traditional custom formulation approach, but this is what I would use in this situation.
> 
> Realize even with a perfect formulated #/M number, that moving a spreader over an area the actual #/M applied to the ground will not be perfect exact for each M area, it's a desired target.
> 
> ...


I am so not a math person this is tough for me to comprehend but I defiintely trust you - you look like you know exactly what you are talking about.

Only question is I only have 50 pounds of the higher weight mix which looks like the first line at 5lb. It only comes in 50 pound bags, (of course)

I could compensate because I have 25 lbs of the other mix which is what looks like you have on the second line there. Could that potentially make up for it?


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## g-man (Jun 15, 2017)

I would not buy anything more. This is an overseeds not a Reno. The numbers are a guidance. An extra 10lb over 17k are not going to make a huge difference.


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## Powhatan (Dec 15, 2017)

If your concerned about 1 lb ( 51 lb vs 50 lb ) don't be. A 1 lb difference spread over 17 M is negligible.

If you can only get seed bag quantities larger than what you need, measure out what you need for the project at hand, and store the rest in a cool dry place for future use. I highly doubt we ever see 100% seed germination, so you'll probably need to put down some more seed sometime in the future.


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## MichiganGreen (Aug 7, 2018)

g-man said:


> I would not buy anything more. This is an overseeds not a Reno. The numbers are a guidance. An extra 10lb over 17k are not going to make a huge difference.


Oh yeah I'm not concerned about the 51 vs 50 as @Powhatan mentions below, it was more that I'm not way off - I want at least a ballpark plan. Going in I was thinking ok, I'll do all 50 over the whole lawn and all 25 over the whole lawn. Now from doing some math it sounds like that might be really heavy. But maybe not...

Part of it could be because I'm trying to tackle this quite literally during semi-important meetings because I'm so enthusastic, but at the same time, not a math person at all and it's going over my head.


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## MichiganGreen (Aug 7, 2018)

Powhatan said:


> If your concerned about 1 lb ( 51 lb vs 50 lb ) don't be. A 1 lb difference spread over 17 M is negligible.
> 
> If you can only get seed bag quantities larger than what you need, measure out what you need for the project at hand, and store the rest in a cool dry place for future use. I highly doubt we ever see 100% seed germination, so you'll probably need to put down some more seed sometime in the future.


Correct - not worried about 51/50 difference - I'm just trying to be sure doing the full 50 and full 25 isn't too much overall, as 75 pounds total. Also the big curveball is the fact that they have very different seeding rates - 4-7 on one of them, and just 3 on the other.


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## Powhatan (Dec 15, 2017)

Overseed rate is usually half of new lawn seed rate. 3#/M for KBG is a typical new lawn rate.

25 lb bag / 17 M = 1.47#/M <-- that is half of 3#/M

If your not comfortable mixing amounts with one spreader rate setting, then apply separately as previously recommended, just means you get more exercise. :thumbup:


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## PA Lawn Guy (Jul 2, 2018)

If you spread separately, does anyone ever consider throwing down the KBG first and then the TTTF a week or so later?


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## Green (Dec 24, 2017)

PA Lawn Guy said:


> If you spread separately, does anyone ever consider throwing down the KBG first and then the TTTF a week or so later?


Yeah, but not quite a week. After 5 days, it tends to start germinating and you don't want to step on it after 5 days or so.

Only issue is you can't topdress if you're going to add more seed a few days later.


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## MichiganGreen (Aug 7, 2018)

Green said:


> PA Lawn Guy said:
> 
> 
> > If you spread separately, does anyone ever consider throwing down the KBG first and then the TTTF a week or so later?
> ...


What if you topdress first? Was going to double aerate, cut low then spread peat just in the bad areas. This is the first I've seen of breaking it up timewise


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## MichiganGreen (Aug 7, 2018)

Powhatan said:


> Overseed rate is usually half of new lawn seed rate. 3#/M for KBG is a typical new lawn rate.
> 
> 25 lb bag / 17 M = 1.47#/M <-- that is half of 3#/M
> 
> If your not comfortable mixing amounts with one spreader rate setting, then apply separately as previously recommended, just means you get more exercise. :thumbup:


Wife would say do the exercise...those are the overseed settings. In fact for the Cornell classic there is only one number, 3 lbs. Tttf shows like 6-10 or 9 for bare and 4-7 for over


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## Suburban Jungle Life (Mar 1, 2018)

What if you pre-germinate the KBG and seed both on the same day?


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## MichiganGreen (Aug 7, 2018)

Suburban Jungle Life said:


> What if you pre-germinate the KBG and seed both on the same day?


How do you pre-germinate? Only thing like that I've done is a dozen jalapeno plants over the winter this year in a small planter. Have never heard about this for grass!


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## LawnSolo (Jul 17, 2018)

This is very interesting. I googled several articles and it seems like a good idea however I fear the seeds will be too sticky or wet to be used with a rotary spreader.


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## MichiganGreen (Aug 7, 2018)

So yeah, either I'm horrible at math (which is true), or it's an unsolvable problem, but I'm just going to lay down all of the seed I have. 50 lbs TTTF (recommended 5-7lb / sq ft) and 25 lbs Cornell Classic (recommended 3lb/1k sq ft), in 2 separate seedings. I'll just go over it on the low setting on my spreader to be sure I'm getting good coverage.

Havne't decided if I want to lay peat or not on 17K sq ft...I might just double aerate, lay starter fert, and maybe more milo - should I do a little milo about a week in or maybe a week prior? I did a full dose about 3 weeks ago and don't want to overdo the N


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## Mozart (Jul 17, 2018)

MichiganGreen said:


> So the time is fast approaching to drop all this...Total of 17,000 sq ft.
> 
> I'm going to be using this:
> https://www.homedepot.com/tool-truck-rental/Overseeder/TS-20HD/
> ...


Didn't read whole thread but mix it all together and apply at 4.5lbs per 1000 sqft and this will in effect apply the mixture at "100% combined rate". The 75 lbs will cover 16,667 sqft. Hope this helps


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## MichiganGreen (Aug 7, 2018)

Mozart said:


> MichiganGreen said:
> 
> 
> > So the time is fast approaching to drop all this...Total of 17,000 sq ft.
> ...


Huge help. However. Can I ask how I would know what setting acotts dlx spreader would get me that 4.5 lbs? I will look perhaps there is a chart on their site. But you're happy with that mix of 4.5 for both given that they suggest different weights on the instructions though? Is that because I am already mixing at a 2:1 ratio of 50:25 lbs?

Part 2: how can I be assured I will make the "perfect spread" and distribute evenly. I was planning to start at a low setting and just keep going over whole lawn until gone.

Part 3: any advice on how to mix most evenly? Because the seeds are different sizes I dont want to risk them separating.

Thanks, @Mozart

I know I've been all over this thread I have just spent a lot of money and I cant afford to not get my money's worth. Many thanks to all.


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## Mozart (Jul 17, 2018)

The suggestion above will give you a 50/50 mix of the TTTF and KBG mix. This assumes a 6lb/1000 sqft application for TTTF and 3lb/1000 for KBG.

You could theoretically make any mix you want. For example if you wanted a 75% TTTF and 25% KBG The calculation is as follows:

For 1000 sqft you would need .75*6 =4.5 lbs of TTTF and .25*3 = .75 lbs of KBG and you would apply that mixture at 5.25 lbs per sqft.

You would then need 17,000/1000*4.5 = 76.5 lbs of TTTF and 17000/1000*.75 = 12.5 lbs of KBG, mixed together well.

Not sure how to advise on setting a spreader but in general I would suggest you aim to apply 50% on your first pass. Let's say you end up using setting #8 and apply 60% of the seed on the first pass instead - no problem we just need to adjust the dial down for the second pass. If the hopper opening provides 1 square inch on dial setting #8 we need to find the setting such that the hopper opening will spit out at a slower, appropriate rate. In theory you would rebalance the hopper opening to 40/60*1 square inch or .67 square inches. This should output the remaining 40% of seed over the same area.

There may be some left over as the flow for 1/2 square inch would be less than half of the flow for 1 square inch due to the bottleneck effect having more impact on a smaller opening. So whatever is left just spread by hand.

Disclaimer: this is just a mathematical/theoretical approach, I haven't tried myself yet


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## MichiganGreen (Aug 7, 2018)

This is great, thank you so much. Does anybody have any tips on creating an even blend, so nothing were to settle when i mix it and become weighted more heavy top or bottom? The hopper isnt too large so I'll have to create a blend in a barrel to pull from or something.


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## Suburban Jungle Life (Mar 1, 2018)

MichiganGreen said:


> Suburban Jungle Life said:
> 
> 
> > What if you pre-germinate the KBG and seed both on the same day?
> ...


Put the sack they came in into a buck of water for 5 days. Change the water daily. This will shorten the time they need to germinate. They won't be dry when you remove them from the sack so hang the sack until all the water stops dripping then add something dry like a little peat moss and mixing it together helps to dry them enough to spread through a spreader.


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