Compost Organic Gardening

Is Finished Compost the Only Thing You Need for Your Soil and Plants?

If you’re an organic gardener, even a beginner, I can almost bet you’ve heard of and/or read about compost.

Have the articles that you’ve read given their definition of compost? You can’t assume that their definition of compost is the same as the one you have in your mind.

It’s important to have the same meaning or description of compost as the writer. Otherwise, your brain can “file” the information incorrectly and at some point in the future you’ll have to readjust what you thought you knew.

With that in mind here are my definitions of compost-terms used in this article:

  • Compost is a mixture of decaying organic materials.
  • To compost means to convert to compost (or decaying organic materials).
  • Finished compost is compost that has finished decaying and has stabilized (meaning, it is unlikely to change further).

Magic Elixir?

As much as it’s promoted, it would be easy to consider finished compost the magic elixir that guarantees success in the garden.

Whether it does or not, would depend on how you use it.

Energy from Organic Residues is Needed for Soil Improvement and Fertility

Soil scientist Robert Parnes documented invaluable information for us in his book Soil Fertility. And it’s information you usually don’t see elsewhere.

The book came out of the research at Wood End Laboratory, a soil testing facility in Maine. Originally published in 1985, it was updated in 1990 and then again in 2013. It’s available to the public for free online.

As mentioned in a previous post, Parnes states that energy from organic residues is required to maintain soil fertility and there is no substitute.

What Are Organic Residues?

Organic means they’re derived from living matter.

Residues are things that remain after a process — such as growth or decay. Grass clippings, your kitchen scrapes, straw, vegetation from a harvested crop, compost, etc.

How to Achieve ALL the Benefits from Organic Matter

Parnes explains that in the process of decay, organic raw materials pass through several stages. Each stage has a unique effect on (or contribution to make to) the soil.

The amount of biological activity (from all the soil organisms involved in decay) is determined by how much energy is available from the organic residues. If residues are already partly or totally decomposed (like compost) then you have lost energy.

Parnes puts it this way: “ — the lost energy has been exchanged for beneficial organic by products.” For example, with compost its “value lies in the nitrogen and minerals it contains, which eventually become available” to plants.

Another example would be shredded leaves. Certainly they will still benefit your garden, but you will lose a stage of the decay process which would contribute to the soil in its unique way.

It’s important to understand that it’s the high biological activity (during the decay process) that actually

  • improves the physical condition of the soil,
  • improves its drainage,
  • gives it the ability to hold water,
  • promotes aeration and,
  • provides food for the soil organisms.

Then the soil organisms can

  • fix nitrogen from the air,
  • form symbiotic relationship with roots of plants,
  • produce vitamins and growth hormones,
  • prey on plant pathogens, and
  • all the other things that benefit your plants that scientist don’t yet know.

Diversity and high activity by soil life is necessary to achieve all the benefits of organic matter (starting as raw organic residues) in the soil.

Final Thoughts

After hearing what this noted soil scientist documented, you may want to rethink what you expect from or how you use finished compost.

I know I did.

You may also find it beneficial to review the two posts I’ve linked to under Related Posts below.


Related Posts:

Organic Residues – The Needed Energy for Soil Fertility

Mulching – Weeds, Annuals, Crop Residue to the Rescue


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  • Theresa

    Thank You again.

    I have never quite thought of compost in this way, but I mulch my leaves right on the lawn to naturally compost over the winter. The lawn is receiving most of the energy. I know some is converted to heat that is lost into the air.

    Plus when I was building up my soil in the garden, (clay) I would put three feet of leaves on it over the winter and not all of it would totally decay and I would til all of it into the soil, so I did get some benefit from the leaves composting more in the soil.

    My brother told me years ago to compost my egg shells along with all kitchen scraps, plus I have composted coffee grounds and many other things with varying degrees of benefit.

    I hope you are doing well and I appreciate that you are still putting out your “blog”.


  • Theresa, this makes me feel better about my increasingly lazy approach to building soil fertility. I do more chop and drop right in the garden now than ever. I will haul compost up to the garden when renewing or building a bed, then the rest of the action over the course of the growing season is just adding plant material to the top of the soil. Thank you for mitigating the guilt I was feeling about being lazy! LOL!


  • I’ve done chop and drop for years, Pat. As you know, it works great!
    As does laying other vegetation on top of the beds during the season.

    There’s always so much to do in life that we don’t need any extra jobs. 🙂

  • Last spring, my friend cleaned out the chicken coop and put everything on the garden beds, instead of the compost pile. It was a month before planting, but I was worried. Turned out to be the best harvest in years. One thing is, everything was put on top of the soil and not mixed in (am no-till), which may be related to the good results.

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