Aerating and overseeding

bavaria-n

LawnSite Member
Location
Long Island NY
Aerator makes holes about 2-3 inch deep. If grass seeds germinate that deep and after few months the holes collapse/close, the soil will chock and kill the grass . Then what sense has over seeding ?
 

EricC

LawnSite Bronze Member
I figure every way you do it results in lost seed and some results in more lost time with less lost seed and less lost time and more lost seed. I'm sure the fate of some seeds is exactly as you describe, but for every seed that drops 3 inches down a hole, there are others that don't land that far down or actually germinate on the soil layer above from the cores melting. and then a whole bunch of others that don't do anything.

That said, i'm getting ready to do this in NE Wisconsin and I do have a question. Last time I did this I rented a slice seeder and it was not a great experience to say the least. So i'm going with aeration and overseed this fall.

I am cutting at about 3 3/4 right now, but temps are starting to cool some. No more 90's. Just 70's and 80's. Soil temps are still about 70 degrees so should get quicker germination. But i've been reading around, I have the aerator rented for next weekend. do I just go right from 3 3/4 down to 2", aerate and seed?

Or would it be better to make take 3 cuts between now and then giving a day or 2 in between and take it from the 3 3/4 down to 2 a half inch or so at a time? and then aerate and seed.

Next question. Some say keep cutting at the 2" so seed gets better sun and warmth others say don't cut until it's 4" or more? I'm inclined to keep it around that 2" mark, but not sure.
 

Jefflac02

LawnSite Member
Are you going to irrigation available to water daily? That would be the most important key in answering your question.

Going from 3 3/4” to 2” is going to put extra stress on the existing turf if you do it all at once. So mowing 3 times and lowering taking the 1/3 rule into account would be the best approach. I would take it even down to 1 1/2” if you have a fairly level lawn. You may want to even top dress with compost before you overseed to really kick things up.
 
OP
B

bavaria-n

LawnSite Member
Location
Long Island NY
I figure every way you do it results in lost seed and some results in more lost time with less lost seed and less lost time and more lost seed. I'm sure the fate of some seeds is exactly as you describe, but for every seed that drops 3 inches down a hole, there are others that don't land that far down or actually germinate on the soil layer above from the cores melting. and then a whole bunch of others that don't do anything.

That said, i'm getting ready to do this in NE Wisconsin and I do have a question. Last time I did this I rented a slice seeder and it was not a great experience to say the least. So i'm going with aeration and overseed this fall.

I am cutting at about 3 3/4 right now, but temps are starting to cool some. No more 90's. Just 70's and 80's. Soil temps are still about 70 degrees so should get quicker germination. But i've been reading around, I have the aerator rented for next weekend. do I just go right from 3 3/4 down to 2", aerate and seed?

Or would it be better to make take 3 cuts between now and then giving a day or 2 in between and take it from the 3 3/4 down to 2 a half inch or so at a time? and then aerate and seed.

Next question. Some say keep cutting at the 2" so seed gets better sun and warmth others say don't cut until it's 4" or more? I'm inclined to keep it around that 2" mark, but not sure.
If i'm not sure and get mixed advices from people, then I experiment by my self. This is the best way to find true answer...
 

EricC

LawnSite Bronze Member
Are you going to irrigation available to water daily? That would be the most important key in answering your question.

Going from 3 3/4” to 2” is going to put extra stress on the existing turf if you do it all at once. So mowing 3 times and lowering taking the 1/3 rule into account would be the best approach. I would take it even down to 1 1/2” if you have a fairly level lawn. You may want to even top dress with compost before you overseed to really kick things up.
only the .5 acres immediately around the house, the rest is relying on nature. Less than perfect I know going in and a roll of the dice. we're usually wet enough thru fall that it will still work ok.
 

RigglePLC

LawnSite Fanatic
Location
Grand Rapids MI
All good questions, Eric.
Lots of advice out there--but most of it is copied from earlier articles.
There is very little actual data.
Nobody has proof as to which overseeding method works the best. What percent does any method increase the germination?
If you have deep holes, shallow holes, or double holes--one inch deep--which is best?
And how do you determine the percentage of seed that takes hold?
Not sure--I think there is an advantage to dropping the cores on top of the seed.
Yes, I have put seeds at the bottom of holes. Some germinated--but would the plants be normal? Would this mean the new grass plants have the crown buried 3 inches deep?

Does anyone have a machine that pulverizes the cores and applies the soil on top of the seed?

I am trying to do a small experiment comparing sowing seed before cutting the grass short--OR--cut the grass short and only then sow seed. Frustrating--no results so far. Turf type tall fescue.
 

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