# maintaining soil level relative to concrete



## NoslracNevok (Jun 12, 2018)

I renovated the majority of my front lawn last fall. Among the many reasons for the reno, it irked me how the soil level was higher than the concrete sidewalks and driveway :evil: . For my 2017 reno, I made the soil level about 1.5" lower than the concrete. With the grass and normal soil movement, it's only a slight bump up as the mower transitions onto the concrete. 

In a future reno, I will have a lower HOC, perhaps even make it a putting green (a ton of input!), however I'm concerned routinely adding top dressing (needed to minimize the negative impacts of excessive organic material), will eventually raise the soil level far above the concrete areas. How can this be avoided, or is it something I don't have to worry about?


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## g-man (Jun 15, 2017)

From experience, you dont want the lawn below the concrete. The 2in rollers will hit the concrete and not go over it.


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## NoslracNevok (Jun 12, 2018)

Thanks @g-man , I would attempt to make my future reno as close to level as possible, perhaps a little higher so water will run off instead of pooling like it sometimes does now (I'm on a slope).

That said, how does one address the accumulation of sand/top dressing raising the soil height? Spitballing: remove same mass of cores as I add in topdressing?


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## Suburban Jungle Life (Mar 1, 2018)

So, how do you lower it? Core aerate and collect cores year after year?


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## g-man (Jun 15, 2017)

A member, I don't recall who, rented a sod cutter. Removed the lawn as sod, lower it and then placed the lawn back.

Some of my trench lines are a bit high (I was hoping for them to drop more). I used a hand aerator to remove cores. It helped a little bit, but it still needs more or more time for the soil to settle.


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## NoslracNevok (Jun 12, 2018)

@Suburban Jungle Life That would work, however it would be unsightly and a decrease my ability to prevent undesirable plants making a home.

@g-man I think the sod cutter plan is the only option if this ever becomes an issue. It may take years to accumulate high enough to become a nuisance.


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## ABC123 (Jul 14, 2017)

I've been thinking about this too. You could core aerate heavily, collect the cores and try to use a dethatcher to lower the canopy. After all that I'd tenacity and water, water, water. If it doesn't recover you could re seed then.


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## osuturfman (Aug 12, 2017)

If you're topdressing at an optimum level, you're going to gain 1/3-1/2 inch of profile each year. This is equivalent to 30-40 cubic feet of sand/M annually.

M = 1,000 sq ft

This is a frequent issue on collars around putting greens. Two options are:

1.) Sod cutter to a depth 1-2" below the topdressing interface in your profile, grade your subgrade and check with a board or laser level. Do this in the early fall, keep it watered and allow it to push roots going to into winter.

2.) Core or solid tine as deep as you can, with a goal of disturbing at least 5% of the surface. Do this as late in the season as possible before freezing conditions set in. Allow those holes/channels to stay there all winter and freeze/thaw. As ground firms up in early spring, rent a plate compactor and tamp the area to grade with the concrete.

Both are effective methods however, Option 1 is definitely better and more long-lived than Option 2.

Best of luck!


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## NoslracNevok (Jun 12, 2018)

@osuturfman I like option 1, however would you foresee a problem getting a sod cutter close enough to the edge to avoid putting the small strip by hand?


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## osuturfman (Aug 12, 2017)

NoslracNevok said:


> @osuturfman I like option 1, however would you foresee a problem getting a sod cutter close enough to the edge to avoid putting the small strip by hand?


A very incisive question! Here's a few more details/notes on Option #1.

A.) Measure from the concrete edge, the width of the sod cutter plus 8". I would then mark your final width and the inside edge of the sod cutter width with either shaving cream or baby powder. Those are both great marking choices because they won't damage your turf, there will be no unsightly paint marks for the grass to grow out of, and they're both cheaper than water-based turf paint. Marking a straight line for both inside and outside edges of your sod cutter width is critical to making sure you're not left with some odd-shaped triangle pieces. Use the concrete edge to check your line to square over the length of your pass. Doing a width wider than just one sod cutter pass will give you some more room to slightly taper your grade from lawn to concrete, as needed.

B.) Once you have the sod cutter pass cut and set aside, now you can use a sod lifting tool to undercut and section off slabs of the remaining 8" from sod cutter pass to concrete. See this link for example of the tool. https://www.amazon.com/Bully-Tools-92390-12-Gauge-Fiberglass/dp/B0031575IG

C.) Rent or use a small tiller (a Mantis will work great for this!) to till your subgrade once it is exposed. From there you can remove as much material as needed to get on-grade and check using a straight piece of lumber or a 1" galvanized pipe to span from concrete to existing grass in the lawn. So long as the gap between subgrade and concrete match the thickness of the sod, you're good to go. After you have this grade set, till your subgrade again, re-check grade, then replace sod when ready. The reason for tilling the subgrade is to allow your topdressing layer and native soil to bind together and break up any interface between roots on the bottom of your sod and the subgrade soil they will grow into.

D.) Make sure your sod seams are very tight (no gaps) then lightly hand tamp the sod to finish.

Take your time, do the details, and you'll be damn proud of the result.


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## NoslracNevok (Jun 12, 2018)

@osuturfman

Thank you! This makes perfect sense, and thank you for detailed steps. It's very difficult to find sources for this specific situation!

One other thing, when cutting the sod, I've read (I believe it was USGA) the sod should be cut as thin as possible as to minimize the thatch (or something to that effect). Does this ring true with your experience?


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## llO0DQLE (Dec 4, 2017)

Very nice OSU! Thanks for sharing your expertise.


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## osuturfman (Aug 12, 2017)

NoslracNevok said:


> @osuturfman
> 
> Thank you! This makes perfect sense, and thank you for detailed steps. It's very difficult to find sources for this specific situation!
> 
> One other thing, when cutting the sod, I've read (I believe it was USGA) the sod should be cut as thin as possible as to minimize the thatch (or something to that effect). Does this ring true with your experience?


I would cut it at least 1" thick.


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## Seeking_Turf (May 2, 2018)

g-man said:


> A member, I don't recall who, rented a sod cutter. Removed the lawn as sod, lower it and then placed the lawn back.


That was me. The sod cutter worked like a charm. You can see the results in my thread here: https://thelawnforum.com/viewtopic.php?f=9&t=2651&hilit=seeking+turf

I set the sod cutter as deep as it would go trying to minimize root damage as much as possible. Worked out well for me. Hope this helps :thumbup:


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