# How to improve soil under an existing lawn



## dsimonid (Aug 6, 2010)

Several spots in our 2-year old lawn are dying from lack of rain. It appears to be where more builder's sand than topsoil exists, such as where the septic tank and fields exist.

Is there a way to improve the soil, and moisture-retaining ability, shy of planting a new lawn?

Thank you.


----------



## Mr Chips (Mar 23, 2008)

sure. you can rake a topsoil "dressing" right into the grass. it will look a little shady for a couple weeks, but if all you have there is dead lawn it might be an improvement. Don't go too heavy. Just rake it in so the grass is protruding out. do it in now, late fall, and again in spring if need be. if you have a good compost pile, add some of that

I have the opposite problem: a lot of clay in my soil. I rake in 7-10 big bales of peat moss into my lawn every spring. the drainage is getting a lot better, but it's a slow process for sure....


----------



## Tom Struble (Dec 29, 2008)

gypsum a good soil additive use to improve the soils structure


----------



## Mr Chips (Mar 23, 2008)

tomstruble said:


> gypsum a good soil additive use to improve the soils structure


yea, i use gyp also, but there seems to be a lot of conflicting "experts" when it comes to gypsum. You can never go wrong adding organic matter like peat and compost IMO


----------



## chrisn (Dec 23, 2007)

Mr Chips said:


> yea, i use gyp also, but there seems to be a lot of conflicting "experts" when it comes to gypsum. You can never go wrong adding organic matter like peat and compost IMO


 
that and a little cow or horse crap:laughing:


----------



## downunder (Jun 13, 2008)

My 2c worth-

The idea of raking in some topsoil dressing could have some use but could be expensive and labor intensive. I would core aerate first and hopefully some of the topsoil will find its way into the plug holes.

Gypsum has some benefit for loosening heavy clay soils in a limited area. Wholesale application as one might do with lime is generally useless.

It has been my experience that peat (and I use it routinely) is for moisture holding more than drainage. Perilite, coarse sand and, to some extent, vermiculite are for that purpose. Peat is very acidic. This should be considered when using it for crop that are pH sensitive.


----------



## Mr Chips (Mar 23, 2008)

downunder said:


> My 2c worth-
> 
> The idea of raking in some topsoil dressing could have some use but could be expensive and labor intensive.


VERY cheap and VERY easy. you literally dump it and rake it



downunder said:


> Gypsum has some benefit for loosening heavy clay soils in a limited area. Wholesale application as one might do with lime is generally useless.


Not necisarily true, there is a lot of debate on this topic



downunder said:


> It has been my experience that peat (and I use it routinely) is for moisture holding more than drainage.


Peat has great moisture holding properties, but it doesn't change the fact that its a great additive to help loosen packed clay over time


----------



## AllanJ (Nov 24, 2007)

In order to both improve the soil under a lawn and not raise (the level of) the lawn, you must remove some of the not so good soil first.


----------



## AllanJ (Nov 24, 2007)

If you don't take away the clippings when you mow the lawn (chopping up, or mulching, the clippings is preferred) then the soil will enrich itself although the level of the lawn will be raised a tad.


----------



## Mr Chips (Mar 23, 2008)

AllanJ said:


> In order to both improve the soil under a lawn and not raise (the level of) the lawn, you must remove some of the not so good soil first.





AllanJ said:


> If you don't take away the clippings when you mow the lawn (chopping up, or mulching, the clippings is preferred) then the soil will enrich itself although the level of the lawn will be raised a tad.


Maybe but it won't happen overnight. I've been raking in topsoil and peatmoss on my lawn every spring for the last 3 or 4 years, as well as mulching EVERYTIME i mow the law, and there is ZERO noticable differance in the overall height of my yard


----------



## concretemasonry (Oct 10, 2006)

Core aeration will open up the surface and provide an efficient space for whatever you want to apply. It has been used routinely several times a year on the better golf courses (except for a week after until the cores breakdown) and the following applications will go into the voids with some watering.


----------



## Mr Chips (Mar 23, 2008)

concretemasonry said:


> Core aeration will open up the surface and provide an efficient space for whatever you want to apply. It has been used routinely several times a year on the better golf courses (except for a week after until the cores breakdown) and the following applications will go into the voids with some watering.


Make sure you don't aerate during drought conditions, this can really stress a lawn


----------



## piste (Oct 7, 2009)

I've done a ton of research on this and one common approach has clearly emerged. But it does take a number of years. You don't need to remove anything...unless of course you want to go the route of ripping everything up...tilling in organics etc etc. But presuming you want to start from where you are.

First and foremost...BEST thing you can do (and for any lawn for that matter) is core aerate. With a compacted clay situation...do it spring and fall for AT LEAST 5 years...then maybe switch to just fall...forever.

Second, and do this right after core aeration...top dress. Not only does that provide much needed organic matter for the soil...it feeds the worms which end up doing a great deal of aerating through tunnelling and help via worm droppings.

The above two steps seem indisputable.

Beyond that...keep to a good fertilization program....and on that I'm going to switch mine to organic in the next year or so. Mulch every time you mow if possible to return nutrients in the clippings which will not at all raise the level of the lawn. Also mow high...I keep to 3" most of the year.... a bit lower at beginning and end of season...but never below 2.5". You can throw some gypsum and/or coarse sand down from time to time if you want but there's much debate on the efficacy of that. Beyond that all you need is patience. And yes top dressing can get a bit costly if you are paying someone to spread it. Good luck.


----------



## Mr Chips (Mar 23, 2008)

piste said:


> The above two steps seem indisputable.
> 
> Beyond that...keep to a good fertilization program....and on that I'm going to switch mine to organic in the next year or so. Mulch every time you mow if possible to return nutrients in the clippings which will not at all raise the level of the lawn. Also mow high...I keep to 3" most of the year.... a bit lower at beginning and end of season...but never below 2.5". You can throw some gypsum and/or coarse sand down from time to time if you want but there's much debate on the efficacy of that. Beyond that all you need is patience. And yes top dressing can get a bit costly if you are paying someone to spread it. Good luck.


I have clay soil, and have also done a lot of research and agree with everything in your post. I'd like to add that before you start adding sand, do your research. this is heavily debated ( as you mentioned) and many feel that if you use the wrong type of sand, you will do more harm than good. Also if cost is a concern, think twice about gypsum. It's pretty expensive, and it's not clear on how much it helps. Gypsum probably won't hurt at all, but IMO topdressing will do a lot more good, and pound for pound is a heck of a lot cheaper. I also mow at the highest setting and mulch the clippings, and when all my neighbors yards go brown when it's dry, mine stays a lot more green without any watering


----------



## bob22 (May 28, 2008)

Gypsum; one view:
http://gardening.wsu.edu/library/lanb003/lanb003.htm


----------



## Mr Chips (Mar 23, 2008)

bob22 said:


> Gypsum; one view:
> http://gardening.wsu.edu/library/lanb003/lanb003.htm


YUP! I have seen a lot of similiar reports. I use it anyway, as i figure it can't hurt, but i don't go crazy with it, it does seem to help the areas where my dog "helps water the lawn"


----------



## fallingstar (Aug 20, 2010)

I had a soil test done at the local nursery. The store clerk told me to sprinkle lime on the lawn.

fs


----------



## downunder (Jun 13, 2008)

> Gypsum probably won't hurt at all, but IMO topdressing will do a lot more good, and pound for pound is a heck of a lot cheaper.


May I ask the quality of this topdressing? This is a rather generic term which one could use for anything applied to the surface in a thin layer whether it be sand, topsoil, gypsum, manure or whatever (without further digression into the definition of "thin"). I have not found this to be true in buying gypsum by the pallet vs good topsoil by the dumptruck load.



> I've done a ton of research on this


I've done some research but I have a lot of commercial *experience* with other people's money based on that research.


----------



## Mr Chips (Mar 23, 2008)

downunder said:


> May I ask the quality of this topdressing? This is a rather generic term which one could use for anything applied to the surface in a thin layer whether it be sand, topsoil, gypsum, manure or whatever (without further digression into the definition of "thin"). I have not found this to be true in buying gypsum by the pallet vs good topsoil by the dumptruck load.
> 
> 
> I've done some research but I have a lot of commercial *experience* with other people's money based on that research.


I have never bought gypsum by the ballet, but i have bought by the bag at the home centers and such At close to $8 for a 40lb bag its more expensive than any topsoil i have ever seen.

It's great that you have experience, but just because you say you've done it, doesn't mean that there isn't a better way


----------



## piste (Oct 7, 2009)

downunder said:


> May I ask the quality of this topdressing? This is a rather generic term which one could use for anything applied to the surface in a thin layer whether it be sand, topsoil, gypsum, manure or whatever (without further digression into the definition of "thin"). I have not found this to be true in buying gypsum by the pallet vs good topsoil by the dumptruck load.
> 
> 
> I've done some research but I have a lot of commercial *experience* with other people's money based on that research.


Myself I use what my local garden center calls a "leaf mulch". It's a light compost and the place I get it from is highly knowledgeable and only carries quality products.

Not sure why cost of gypsum is being compared to top soil as they would usually be for totally different purposes...one to amend existing conditions and the other usually to replace.

You've done research and have commercial experience......and ?????? Not saying the following applies to you at all...but I have to say a very high percentage of the "professional landscapers" (ie. experienced) don't have the first clue about their chosen area of work. My wife and I do all our own on our 1/2 acre....receive numerous compliments and even awards from time to time....and know far more than "most" professionals with experience. You may be an exception to the rule...but "experience" does not necessarily equate to "competence".


----------



## downunder (Jun 13, 2008)

> but I have to say a very high percentage of the "professional landscapers" (ie. experienced) don't have the first clue about their chosen area of work.


I call those guys "contractors" and take offense (not to you) if someone associates me with the same. They are in it to make money. I do it because I enjoy it. Just because someone cuts grass with a $10,000 Exmark, it doesn't make him a professional. He just has an expensive lawnmower that he charges you $85 hour to operate. If someone hasnt' "been there, done that," doesn't know the difference between perlite and vermiculite, black spot from rust, or nutsedge from poison ivy and/or hasn't taken the time to get an education and learn what effect pH can have on nutrient uptake, I don't call him/her a professional.

My father was raised on a farm and my mother was a floral designer when I was growing up. I did homework at a wreath picking table. But back to the point- the University of Georgia seems to think that I know what I am doing, at least according to the paper. And I have won awards and compliments from the citizens (who pay my salary) and neighbors for my flower beds. And I agree that you don't have to have a degree to know what you are doing, just caring to make the world a little nicer, whether in your own yard, through a vocation, or volunteering.

My commercial experience just enables me to try things that I might not spend the money on at home. Like buying fifteen bags of perlite to loosen a 200 ft2 bed or a ton of Nature's Helper. I don't like sand because I don't like my hands in the grit. I like organics that feel good. If the soil feels good to me, then the plants will like it.


----------



## Rustigger (Sep 19, 2010)

I am in GA and have a zoysia lawn that was just hanging in there due to the drought over the years. The trees have gotten so big and I have soooo many leaves that I mow/mulch them into the grass. One particular area got a ton last fall!!! That area this year has grown and greened up like gang busters. I plan to send the leaves to another area this year to see if it helps. Stay organic and your soil will improve.


----------



## josephine (Sep 21, 2010)

Peat moss gets my sinuses all unhappy. For any soil improvement I use coir. That is not as acidic. And it does not wick all of the water out of surrounding soil like peat moss does. I also use rabbit feed, not just the poop, though that probably would be great in some amount. The feed has mostly alfalfa--good vegetation matter, very low sodium, trace minerals--including iodine, the 3 N-P-K in small amounts, and is easy to handle. I dig that, almost every year, into my garden beds along with leaves and small twigs that are around. The season's worth of kitchen trimmings have been dug-in around the yard in possible, future, growing-bed sites. I like DirtDoctor.com


----------



## Stillwerkin (Nov 24, 2008)

If all else fails, I suppose you could rent a sod cutter, tiller, and re-multch one section at a time.


----------

