Return to the Soil Forum | Post a Follow-Up

 o
Adding lots of compost to garden

Posted by TrpnBils 6B (My Page) on
Mon, Feb 10, 14 at 16:42

Last year, my garden was brand new and we had some great yields. I went through and sifted rocks out of the soil, and it's not too terrible, but it's a little on the clay side and I'm sure it could be better. Our outdoor compost pile didn't amount to much, and our indoor vermicomposting bin is still relatively new so it won't be contributing a whole heck of a lot to the garden this spring.

I recently found out that a city about 30 miles from us has a community composting program (assuming mostly grass clippings and downed leaves, but I don't know for sure) and they offer free compost to anyone who can haul it away.

This year I'm starting a couple of raised beds in addition to my traditional garden and am planning on taking advantage of the free compost when it warms up a bit. Would it benefit me to get a truck load for my garden to till in, or should I hold out and pay for something like mushroom compost that I know its composition, more or less?

It makes sense to me that compost is good, regardless, but with how well we did last year I'm hesitant to put a whole lot of something into the entire garden because if it does more harm than good it's basically irreversible on a short time scale.


Follow-Up Postings:

 o
RE: Adding lots of compost to garden

Mushroom compost is almost nutrient-bare stuff...and can be quite sterile/spent. Personally, I'm not a fan of it except for the sole purpose of improving soil structure because it generally brings very little besides that "to the party."


 o
RE: Adding lots of compost to garden

Interesting... so you think I'd be better off with the "community compost" stuff? Apparently this program has been going on for years, so I'd imagine they have a decent amount of aged compost available.


 o
RE: Adding lots of compost to garden

Compost is a good soil amendment for both clay and sandy soil. Since your beds are just a year old, add some more compost. Incidentally, my beds are also a year old. In the fall I mixed in lots of leaves and added some compost and covered them with plastic(To keep it warmer for the worms and the micro organism, and prevent leaching the nutrients) I will re condition then next spring again.


 o
RE: Adding lots of compost to garden

There are those that think Spent Mushroom Compost is of little value in the garden and yet science shows it is quite a valuable resource for organic matter to add to soil. Many of us that have used Spent Mushroom Compost as a soil amendment have not found the dire problems often touted by those that have not.
There are germination tests that can tell you if that municipal compost is something you would want to use. Obtain a small amount and put seeds in and watch them. If the germinate and grow with no problems it is good, If the seeds fail to germinate or germinate but die it probably is not something you want.
The soil in your raised beds should be a mixture of the mineral portion of soil and organic matter. The terms "topsoil" and "garden soil" are meaningless so you need to determine what you want and specify that and do not let anyone tell you different.
I have found, over many years, that most people think "topsoil" is Loam, a specific soil type that is about 45 percent sand, 25 percent silt, 25 percent clay and 5 percent organic matter. "Topsoil" is defined as the top 4 to 6 inches of soil. It may contain organic matter or it may not.

Here is a link that might be useful: About Spent Mushroom Compost


 o
RE: Adding lots of compost to garden

If money is an issue, I suggest that you use the layer method as follows: Layer 1) Free composted leaves from your local transfer center if possible, 2) Humus and manure purchased from Home Depot or Lowes on sale. It ussualy costs a bit over a dollar per cubic foot. If available and free use composted manure from a local source. 3) Top soil purchased from Home Depot or Lowes on sale. It ussualy costs a bit over a dollar per cubic foot. 4) More composted leaves. If you are building a raised be on grass or weeds the first layer should be cardboard or double layer of newspaper. The worms love it.


 o
RE: Adding lots of compost to garden

Can you add too much compost to a garden bed? For the past two years I have added a 6 inch layer of compost to my raised beds in the fall, after my summer plants have died off.


 o
RE: Adding lots of compost to garden

"I recently found out that a city about 30 miles from us has a community composting program (assuming mostly grass clippings and downed leaves, but I don't know for sure) and they offer free compost to anyone who can haul it away."

Let me start off by saying the best compost is the conoost you make yourself. Let me also say, last year I picked up yards upon yards of free compost from the city, just like you talk about. My plants did great, but I think they would of did much better with my own compost. Some, like soil scientist Elaine Ingham talks as if city municipal compost is near useless... But, I have to say, if it's clean compost with no pollutants, it would be better than no compost. I'll tell you, If i ran out of my compost, i would be shoveling the cities.. So, it seems fairly decent..

If i was you, I would not pay for the expensive quality black gold that so many nurseries are trying to sell you for 30 bucks a yard.. That probably close to the stuff your going to get from the city. It's how the composter makes/maintains the compost that determines quality. The only real way to see all the organisms and trully see the soil food web, is with a microscope. A simpler way to see if the compost is good, plant radish seeds or some other quick growing plant. The better the growth, the better the compost. But then, if you are using a container.. It all depends on watering, fertilzing,etc. you could have one nutrient poor compost with plants thriving and nutrient rich compost with plants wilting just by the way you water.. So there has to be some control, or the test could be inaccurate thinking one is superior..


I would go with the cheapest/less polluted product(i know they dont neccesary work hand to hand), most likely city compost, then after the beds are filled with that keep adding your own compost/mulch year after year.


 o
RE: Adding lots of compost to garden

  • Posted by jbclem z9b Topanga, Ca (My Page) on
    Mon, Feb 17, 14 at 21:35

If you garden organically, there are a few things to consider. First, grass clippings especially at certain times of the year, are probably going to be pesticide laden, whereas tree leaves and branches won't be. Second, some municipal composting programs use sewage sludge in their compost, and no matter how hot it's been heated, or for how long it's been composted, it's still going to have heavy metals and other undesirable things that come with sewage.

Before I knew anything about sewage sludge, I used free compost from a local city plant. It was 70% processed sewage and 30% ground up wood pallets...their analysis sheets showed that it had very low levels of pathogens and heavy metals. But I found out that whereas 30 years ago they were required to test for some 200 unwanted substances(heavy metals, chemical wastes, antibiotics, etc...), new rules had cut this requirement down to 20 items tested for. So even when the sludge meets the requirements, it can still be full of substances that haven't been tested for.

BTW, fresh, uncontaminated grass is great in a compost pile...I still grow a small patch of Kikuyo grass (watered with grey water) just for my compost pile.


 o
RE: Adding lots of compost to garden

Yes, I would only use city or questionable compost as the last resort. I was cringing shoveling it on my garden... But even, i used cardboard with who knows what in it as a base layer to kill existing vegitation, then piling several inches of compost followed by a few inches of leave/grass clipping mulch. I learned not to freak out about toxins and unhealthy substances in the soil, the organisms in the soil takes care of that, for the most part.. If your not adding more toxins in the form of garden products.. If you use good garden practices and maintain a healthy soil foodweb.


 o
RE: Adding lots of compost to garden

The terms "topsoil" and "garden soil" are meaningless so you need to determine what you want and specify that and do not let anyone tell you different.(PART I)
I have found, over many years, that most people think "topsoil" is Loam, a specific soil type that is about 45 percent sand, 25 percent silt, 25 percent clay and 5 percent organic matter. "Topsoil" is defined as the top 4 to 6 inches of soil. It may contain organic matter or it may not. (KIMMSR)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I think the terms topsoil and garden soil are NOT meaningless. They have conventional meaning. Although it is not like definitions in pure science.

In response to PAT I: How do you determine it? Or how one has to do it?

In response to remaining part of your statement:

I don't think that "MOST PEOPLE" think that topsoil is "45%..25% ..25%..5% ." .as you mentioned. That mixture is a deliberately mixed soil and sold as garden soil/mix. Maybe not in that exact proportion but close to that.
Yes topsoil is a layer of organic matter (decomposed plants remains) mixed with the natural inorganic soil underneath. Beside that, a commercial/family farmland, after years of working and conditioning becomes ssource of topsoil to a good depth. So when such a farmland turned converted into industrial or residential development , the soil is scraped and sold as topsoil. I am sure there are places that mix some compost with any kind of soil and call it topsoil. That would be a fraudulent act, in my opinion


 o
RE: Adding lots of compost to garden

I'm not too terribly worried about organic gardening, although I certainly don't want garbage in my soil. Like I had originally said, I composted everything I could get out of my own yard last year and still only ended up with about maybe 2 5-gallon buckets of compost at the end of the year, so when people talk about adding 2-3+ inches of compost to the garden, I have to wonder what the alternatives are. I'm just trying to avoid paying $3/bag at Lowes when I would have to buy as much as it would take to get a layer like you're all talking about.


 o
RE: Adding lots of compost to garden

The secret to big compost is collecting as mulch leaves as you can in the fall. This applies with grass clippings as well. The neighbors love me for cutting their grass and raking leaves!


 o
RE: Adding lots of compost to garden

Here's a study that measured a bunch of spent mushroom composts and reported the average results:

N 2.7%
P 1.6%
K 2.9%
OM 61% (dry wt)

These numbers are comparable to or higher than most garden variety composts.

Here is a link that might be useful: Plant Nutrients in Mushroom Compost - PA State Univ


 o
RE: Adding lots of compost to garden

This is how Merriam Webster defines "topsoil", ": surface soil usually including the organic layer in which plants have most of their roots and which the farmer turns over in plowing"
The only definition of "garden soil" I could find is from Mississippi State University, "The ideal garden soil is deep, loose, fertile, well-drained (internally as well as on the surface), has plenty of organic matter, and is free of weeds and diseases. Such soils are difficult to find, but with proper preparation and management, less-than-ideal soils can be productive."
Neither really tells you much that would be of help at someplace that sells either "topsoil" or "garden soil".

What passes for "topsoil" in the northwest is not the same thing as "topsoil" even in Utah and Nevada much less Georgia or the Carolinas. What might be "topsoil" in Washington is quite different then what would be "topsoil" in Arizona and New Mexico.
Define what you mean by the terms or don't use them.


 o
RE: Adding lots of compost to garden

  • Posted by jbclem z9b Topanga, Ca (My Page) on
    Mon, Feb 24, 14 at 1:13

You might want to check with local landscapers and ask where they get compost and top soil. I've bought compost by the yard ($30 per cubic yard for small amounts) from a company about an hour's drive from my house. They have two yards and sell many different soil mixtures, including compost made from horse manure(60-70%) and ground up pallets(30-40%). Last time I was there they had 15' high piles of steaming compost and there was a very large truck loading up about 30 yards of the stuff. I'd think landscapers would have to have a local supplier.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Soil Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here