# Top dressing clay with compost. Is it worth it?



## ceriano

Is top dressing with compost worth the time and effort?


----------



## MrMeaner

Yes...everything is b better with compost


----------



## uts

Yes, but what are you trying to achieve? Nutrients, pH, organic matter?


----------



## ceriano

uts said:


> Yes, but what are you trying to achieve? Nutrients, pH, organic matter?


Just to add some organic matter and help with the drainage.


----------



## BobLovesGrass

Some professionals advocate fert and mulching, root cycling will build organic matter down into the clay. Mulched clipping will add to the top. No risk of brining in new weeds or unknown chemical contamination this way.


----------



## bernstem

I think it is worth top dressing with compost despite the small risk of weeds. Top dressed compost will be slow to incorporate into clay due to the tight soil structure. I would recommend core aeration then top dressing to help move the compost deeper into the soil structure. Root cycling and mulch mowing will slowly build organic matter levels but is very slow with turfgrass. I have not seen a real-life example with soil tests showing an appreciable increase in OM level without adding organic matter from outside the system. If anyone has one, let me know. Compost will be the fastest change but requires large volumes of compost. Plan on thousand pounds per 1000 square feet over several years.

The weight of 1000 square feet of soil to 6 inches is ~40,000 lbs. To add 1% to that, you need 4000 lbs. Compost is ~50% water, so you need ~8000 lbs of finished compost to raise the OM level by 1%. You usually top dress with 1/2-3/4 yards of compost per 1000 square feet. 1/2 yard of compost is ~800 lbs, so even with compost it is a long-term plan to raise OM. In my experience, OM levels rise faster than the 10 years the math would suggest, but you should still plan on top dressing for 4-5 years if you want to increase OM amounts.

The good news is that once you raise OM levels, they take a very long time to decline unless you are tilling the soil which greatly accelerates OM breakdown. Since we don't till lawns, the OM should last for a few decades or so once built up.


----------



## ceriano

bernstem said:


> I think it is worth top dressing with compost despite the small risk of weeds. Top dressed compost will be slow to incorporate into clay due to the tight soil structure. I would recommend core aeration then top dressing to help move the compost deeper into the soil structure. Root cycling and mulch mowing will slowly build organic matter levels but is very slow with turfgrass. I have not seen a real-life example with soil tests showing an appreciable increase in OM level without adding organic matter from outside the system. If anyone has one, let me know. Compost will be the fastest change but requires large volumes of compost. Plan on thousand pounds per 1000 square feet over several years.
> 
> The weight of 1000 square feet of soil to 6 inches is ~40,000 lbs. To add 1% to that, you need 4000 lbs. Compost is ~50% water, so you need ~8000 lbs of finished compost to raise the OM level by 1%. You usually top dress with 1/2-3/4 yards of compost per 1000 square feet. 1/2 yard of compost is ~800 lbs, so even with compost it is a long-term plan to raise OM. In my experience, OM levels rise faster than the 10 years the math would suggest, but you should still plan on top dressing for 4-5 years if you want to increase OM amounts.
> 
> The good news is that once you raise OM levels, they take a very long time to decline unless you are tilling the soil which greatly accelerates OM breakdown. Since we don't till lawns, the OM should last for a few decades or so once built up.


My Plan was to do 10 yards per 10,000 SF. I was quoted $1400 so I wasn't sure if it's really worth it.


----------



## bernstem

ceriano said:


> My Plan was to do 10 yards per 10,000 SF. I was quoted $1400 so I wasn't sure if it's really worth it.


1 yard/1k will be a bit heavy, but not too much. The price is also reasonable for my area.


----------



## Lawn Whisperer

ceriano said:


> My Plan was to do 10 yards per 10,000 SF. I was quoted $1400 so I wasn't sure if it's really worth it.


What does that include? Delivery, spreading, aeration, seeding?
When do you plan on getting done? Early spring or late summer would be ideal.


----------



## bernstem

Lawn Whisperer said:


> ceriano said:
> 
> 
> 
> My Plan was to do 10 yards per 10,000 SF. I was quoted $1400 so I wasn't sure if it's really worth it.
> 
> 
> 
> What does that include? Delivery, spreading, aeration, seeding?
Click to expand...

For that price it should include spreading. You can get bulk screened compost delivered for $40-50/yard. If it is 1400 just delivered that is way overpriced.


----------



## ceriano

bernstem said:


> Lawn Whisperer said:
> 
> 
> 
> 
> 
> ceriano said:
> 
> 
> 
> My Plan was to do 10 yards per 10,000 SF. I was quoted $1400 so I wasn't sure if it's really worth it.
> 
> 
> 
> What does that include? Delivery, spreading, aeration, seeding?
> 
> Click to expand...
> 
> For that price it should include spreading. You can get bulk screened compost delivered for $40-50/yard. If it is 1400 just delivered that is way overpriced.
Click to expand...

It included spreading. I probably wait till late summer. New compost should help with seed to soil contact too.


----------



## Lawn Whisperer

Yes compost can help keep the seeds moist. I've done aeration, compost, then slice seeding with great germination results. Others recommend seeding then compost, but I worry about getting the seeds to deep for germination, just make sure they don't bury the seeds to deep (~1/4inch) under the compost.


----------



## ceriano

Lawn Whisperer said:


> Yes compost can help keep the seeds moist. I've done aeration, compost, then slice seeding with great germination results. Others recommend seeding then compost, but I worry about getting the seeds to deep for germination, just make sure they don't bury the seeds to deep (~1/4inch) under the compost.


Was is too much trouble to spread the compost? How long does it take to spread 10 yards?


----------



## Lawn Whisperer

I hired someone to spread 10 yds3 of compost. It took 3 people (1 person spreading, 1 person in the truck, another spreading the sides with a shovel) 7 hours to spread using a mechanical spreader with over a dozen passes on the lawn. The compost was starting to clump due to moisture, so YMMV depending on compost moisture and the method of application.

https://thelawnforum.com/viewtopic.php?p=440536#p440536



Lawn Whisperer said:


> Hired a local landscape company spread a truck load of compost using a  Ecolawn Applicator . Cost of renting and spreading it myself is not worth the savings.


----------



## Jeffersonzoysia

ceriano said:


> bernstem said:
> 
> 
> 
> 
> 
> Lawn Whisperer said:
> 
> 
> 
> What does that include? Delivery, spreading, aeration, seeding?
> 
> 
> 
> For that price it should include spreading. You can get bulk screened compost delivered for $40-50/yard. If it is 1400 just delivered that is way overpriced.
> 
> Click to expand...
> 
> It included spreading. I probably wait till late summer. New compost should help with seed to soil contact too.
Click to expand...

I just received a quote from a local Atlanta area company to core aerate, top dress with 60% sand and 40% earth castings spread and dragged for $2,500 on 10,000 FT2. I also plan on spreading 80 lbs of Andersons Humic Acid to help add carbon to my clay based soil. Reserving date for early-mid April.


----------



## ceriano

Jeffersonzoysia said:


> ceriano said:
> 
> 
> 
> 
> 
> bernstem said:
> 
> 
> 
> For that price it should include spreading. You can get bulk screened compost delivered for $40-50/yard. If it is 1400 just delivered that is way overpriced.
> 
> 
> 
> It included spreading. I probably wait till late summer. New compost should help with seed to soil contact too.
> 
> Click to expand...
> 
> I just received a quote from a local Atlanta area company to core aerate, top dress with 60% sand and 40% earth castings spread and dragged for $2,500 on 10,000 FT2. I also plan on spreading 80 lbs of Andersons Humic Acid to help add carbon to my clay based soil. Reserving date for early-mid April.
Click to expand...

I'm using the LESCO Carbon pro G. It's about $25 bucks per bag.


----------



## Jeffersonzoysia

ceriano said:


> Jeffersonzoysia said:
> 
> 
> 
> 
> 
> ceriano said:
> 
> 
> 
> It included spreading. I probably wait till late summer. New compost should help with seed to soil contact too.
> 
> 
> 
> I just received a quote from a local Atlanta area company to core aerate, top dress with 60% sand and 40% earth castings spread and dragged for $2,500 on 10,000 FT2. I also plan on spreading 80 lbs of Andersons Humic Acid to help add carbon to my clay based soil. Reserving date for early-mid April.
> 
> Click to expand...
> 
> I'm using the LESCO Carbon pro G. It's about $25 bucks per bag.
Click to expand...

I see a 40 lb bag on amazon for $100. Anderson's is 40Lb for $55 on AMLeonard website.
Where are you getting 40 LB bags of LESCO for $25?


----------



## ceriano

Jeffersonzoysia said:


> ceriano said:
> 
> 
> 
> 
> 
> Jeffersonzoysia said:
> 
> 
> 
> I just received a quote from a local Atlanta area company to core aerate, top dress with 60% sand and 40% earth castings spread and dragged for $2,500 on 10,000 FT2. I also plan on spreading 80 lbs of Andersons Humic Acid to help add carbon to my clay based soil. Reserving date for early-mid April.
> 
> 
> 
> I'm using the LESCO Carbon pro G. It's about $25 bucks per bag.
> 
> Click to expand...
> 
> I see a 40 lb bag on amazon for $100. Anderson's is 40Lb for $55 on AMLeonard website.
> Where are you getting 40 LB bags of LESCO for $25?
Click to expand...

SiteOne. Ask for contractor's discount.

https://www.siteone.com/en/10940cpg-lesco-carbon-pro-g-soil-optimizer-sgn-100-40-lb-qgcy/p/633876


----------



## ABC123

Id also recommend root pruning to be an effective way to add organic matter. If you can apply a consistent source of nitrogen it will improve OM over time.


----------



## ceriano

ABC123 said:


> Id also recommend root pruning to be an effective way to add organic matter. If you can apply a consistent source of nitrogen it will improve OM over time.


Root pruning?


----------



## Lawn Whisperer

I think @ABC123 meant root cycling, which is root growth and decomposition. Root pruning in turf is more of root damage due to herbicide application. While they both result in more organic matter in the soil the latter is not an intended outcome.


----------



## ABC123

ceriano said:


> ABC123 said:
> 
> 
> 
> Id also recommend root pruning to be an effective way to add organic matter. If you can apply a consistent source of nitrogen it will improve OM over time.
> 
> 
> 
> Root pruning?
Click to expand...

Its when the roots grow and die off throughout the season. Yeah I might of messed that word up :lol:


----------



## ceriano

I see &#128514; what happens if we ditched the herbicides all together and do a heady re-seeding a couple of times a year? Carb grass eventually dies off and add organic matter. Wouldn't that work?


----------



## mjh648

bernstem said:


> ceriano said:
> 
> 
> 
> My Plan was to do 10 yards per 10,000 SF. I was quoted $1400 so I wasn't sure if it's really worth it.
> 
> 
> 
> 1 yard/1k will be a bit heavy, but not too much. The price is also reasonable for my area.
Click to expand...

I have found that 0.5 yard / 1k was sufficient for my yard.


----------



## Lawn Whisperer

ceriano said:


> I see 😂 what happens if we ditched the herbicides all together and do a heady re-seeding a couple of times a year? Carb grass eventually dies off and add organic matter. Wouldn't that work?


Not necessarily. You can continue to use herbicides and ward of weeds. Fertilize the lawn to have the desirable grass produce healthy roots and they will naturally add more organic matter into the soil.


----------



## shifco

I did 6cy over my 7.5k lawn or so.
Before = https://imgur.com/a/cPxfEtw
After = https://imgur.com/a/AAFB9i1

I spread myself with a wheelbarrow and rake. Was definitely worth it.


----------

