Compost Soil Improvement and/or preparation

Soil Improvement /More on What Changes Poor Soil to Good

I’ve received some emails over the past few months that have indicated a lack of understanding of what changes poor soil to good soil, and about what compost is and isn’t.

One reader, a relatively new gardener, does a lot of searching for information about what he should do.

Not wanting to double-dig his heavy clay soil, he searched for information that would possibly back up his decision, and found an article that he interpreted as showing “that loosening the subsoil led to less need for watering.”

So he wrote and said he decided to double-dig rather than to “use supplemental water forever.”

I read the article. The experiments mentioned in the article were made over a 4 year period on sandy loam soil in conjunction with deep incorporation of “nutrients” which in conventional agriculture is chemical fertilizer.

One cannot state that merely loosening clay soil will decrease use of supplemental water.

When Does the Benefit of Not Watering or Using Less Water  Come?

The 3 keys to success in gardening (see related posts at the end) are synergistic; meaning they work together for a greater result than just using one key. After you loosen soil deeply, add lots of organic materials, and mulch — THEN your soil will begin to change AND THAT’S where you will get the benefit of not having to water or at least being able to water less.

Clay Soil

My first garden was in heavy yellow clay soil. I started improving it right away using the 3 keys. I saw results the first year, but it got better and better every year.

Improved clay soil will be more dense than improved sandy soil, but it’s much better at holding nutrients and makes great soil for growing a garden.

As far as watering, I’ve never watered my garden, because I have no means to do so. But I’ve always had a successful garden.

On with My Reader’s Story

My reader did the double digging and wrote saying that the area was not much higher than ground level. As it turns out he added a – as in one bag – of organic compost.

I thought perhaps it was the best he could do at the time.

Obviously he was not pleased at the results. He wrote later and said,
“It seems like the soil didn’t mix.  — the two (red clay and compost) didn’t seem to unify.”

As I’ve mentioned in many posts, it’s next to impossible to tell what kind of compost you get when you buy it. But let’s assume for a minute that this new gardener had added one bag of the best compost in the world to his newly dug clay ground. Would the results have been any different?


Compost is Organic Matter, But Organic MATERIAL is Needed

In giving this a lot of thought for sometime, I realized that part of the problem is that yes, compost is organic matter — BUT it is not the organic MATERIAL that you want to add to soil, especially heavy clay soil to “change” it into something suitable for gardening. And I’ve never seen any article, including my own articles, that come right out and say it that way.

How I Know

The organic materials that changed my clay soil to a friable dark soil with lots or organic matter was straw, leaves, pine tags, kitchen scraps, and lots of it.

Compost is organic material that has already decomposed and stabilized. In other words – it’s not really changing any more.  (It is organic matter; also referred to as humus.) Although compost can have soil life in it, if you want to create “good” soil from heavy clay, you need organic MATERIALS that have not yet decomposed. They bring more soil life; the kind that will “mix” or “unify” the organic materials with the soil.

Does it happen instantly? No.

The very best time to do this is in the fall so that the soil life will have time to work on the clay (or any soil) over a period of months before planting in the spring. But the main thing is to do it.

Two Common Recommendations

It’s common to see the recommendation on various sites to bring in a load of compost and incorporate it into the soil and use that to start your garden. Whether the result are acceptable or not, will depend on what the gardener knows and what he or she finds acceptable.

Another common recommendation is to buy topsoil. There are no standards, so just about anything can be sold with the name “topsoil”. But if you know and trust the source, you might get lucky.

Will these two common recommendations guarantee you a good garden?


If you’ve used these recommendations in your own garden, keep in mind that you must, at the very least use the second and third key to success if you want better results.

  • Continually (each year) add organic materials to the soil to improve it and keep soil life active and working on your behalf.
  • Mulch

In Closing – Another reader writes:

“– I had a wonderful garden in the Harrisonburg area and now that we’ve moved to Lynchburg, it seems like the soil is a lot more dense and reddish.  Is the best way to simply keep adding compost to it and eventually it will be more like the soil I loved in the Shenandoah Valley?”

There are many benefits to compost and it certainly won’t hurt to add compost.

Although you may not have the exact same soil that you had in Harrisonburg, if you follow my recommendations (the 3 keys) and you add organic MATERIALS (as explained above) you’ll end up with a soil that you love just about as much as your soil at your previous garden.


NOTE: Format has changed.  To leave a comment please scroll down below blocks of “Related Posts”.


All content including photos is copyrighted by  All Rights Reserved.


4 Related Posts:

Mulching –  Weeds – Annuals – Crop Residue to the Rescue

Organic Residues – The Needed Energy for Soil Fertility

Soil Improvement – Your Foundation for Success

Real Soil – Fake Soil – and a Reader’s Question about Mulch


  • Theresa
    I have told you this before, but it might be helpful to your readers. I have lived here 25 years and have heavy clay soil. For about 15 years I raked all of my leaves into the garden, keeping them from blowing with the fence. I was 1-3 feet deep and by spring it was inches. I mixed that into the garden every year for about 15 years. I now have pretty good soil and simply mow my leaves with a mulching blade on my lawn mower and let them fertilize my lawn.

  • Theresa,

    As you have taught nothing makes great soil except organic material and time. I started gardening 5 years ago with heavy red clay. This my 5th year is the sweetest my soil has ever been. Every fall I rake leaves from my yard and add to beds plus I pick up the leaf litter placed on the side of the road for community leaf pick up. Continually add kitchen scraps to my compost bins plus mulch, mulch and mulch. I add chunky compost to my beds meaning it has not completely decomposed but it is swarms with worms and life.

    To new gardeners….patience is what gardening is all about…organic gardening causes one to slow down and smell the roses. Miracle gro gardens are a fantasy not reality nor are they healthy for your body, the environment and they are unsustainable.

    Kristine – “the Lady Chef”

  • A timely post for me; plus good comments from readers. I’ve been stuck now at Step #3; how much and when to keep adding compost and mulch. I have bags of shredded leaves from last fall; I’ll now keep adding on top of soil and around crops. I was saving it to add to my compost bin because I thought it needed to be compost first!

  • Julie – I wish you had emailed me long ago to ask!
    You can never can get too many leaves!
    100% bulk material decays to 5 to 10% organic matter.
    Always, always, always continue to add organic material to the soil every year and always mulch!
    And no — stuff does not have to be composted unless you want to.

  • My brother gave me some bags of chopped leaves and I’v noticed that there are many pine needles in with them. Can I put this in the garden beds or will the pine needles make it too acidic?

  • Jackie, yes you can put pine needles in your garden. That story about pine needles making things acid has been going around for year and years and is totally false.

  • Great post! I was confused for quite some time about what “organic matter” actually meant. But in reading Theresa’s book, posts, and asking her many questions, and following her lead, i too have turned extremely hard packed red clay into the most beautiful easy to work dark and rich soil. It has been so interesting to watch happen.

  • This is helpful info – we have been composting everything b/f it goes in the garden. Another question – how do you define “mulch”?

  • Anita, I’m glad you found this helpful.
    I consider mulch to be any organic material that covers the ground. I use straw for mulch, but pine needles, dry grass clippings and the like will work as well.

  • Thank you, Theresa, for all the info you put out there for us. I recently pulled up my pea plants and am wondering if I can dig those into the bed and plant another crop there right away. Guess I’m not sure if they have to decompose first. The same with chopped up leaves and pine needles – can I work them into the bed, then plant?

  • Jackie, if you want to plant another crop in that bed, I’d pull the old plants and lay them on top of the bed and cover with mulch. That will work great if you’re transplanting things like cukes, tomatoes, etc. If you’re planting a crop that you broadcast the seed, then just sprinkle the bed with a thin layer of straw after broadcasting and put the old plants in the path beside the bed. You can add more mulch as they come up.

    The same applies to leaves and pine needles. Lay them on top of the bed and soil life will eventually pull them down.

    If you “incorporate” organic material into the bed — the best time to do that is in the fall. That way it has time to decompose before planting in the spring. The main reason for this is because soil life will use the available nitrogen in the soil to decompose the material first. You’d want your new crop to have the nitrogen rather than have it go to decomposing stuff.

    Keep in mind — I lay all residue and organic material on top of the soil. Saves me tons of work and I’ve done it for years and years.

    And Jackie — you are so welcome. I think we live in a time that it will be very important to be able to grow some food and I’m happy to help whenever I can.

Leave a Comment