Full of Organic Matter

Even those who know the importance of the organic matter¹ in our soil might not know all of its benefits. There are many!

Organic Matter’s Origins

First, where does the organic matter in our soil come from? Organic matter in our garden soil comes from all that was present the day it became a garden and all of our added mulch, (seedless) weeds left to rot on the surface, roots from previous crops left to rot in the soil, cover crops tilled into the soil, and, most importantly, added cured compost. 

The Benefits of Organic Matter

Organic matter in your soil increases microbial activity and adds tremendous water-holding capacity.  

Since organic matter is food for soil microbes, soils with greater organic matter can support an increased number of microbes. Furthermore, as organic matter is digested by microbes, they release the nutrients stored in the decaying plant materials in forms that are readily usable by living plants. This is why the microbial life of your soil is one of the biggest things you are growing when you’re growing soil. Healthy soil has healthy microbial life, and a ton of it, and nourishes plants naturally. 

When the microbes are done feeding on this new organic matter, it becomes another form of organic matter: humus, a dark, spongy, mostly carbon substance that remains in the soil for hundreds of years if not eroded away. Humus is wonderful for soil. It improves soil texture, continues to hold nutrients in the soil and release them to plants as needed, and can hold almost its own weight in water, making the soil a living sponge that has a sufficient holding capacity to let plants withstand all but the worst dry spells. 

How Much Do You Need?

The ideal soil for garden plants has about five percent organic matter. Again, a free soil test through your county’s cooperative extension will give you an idea of your current organic matter content (search online for instructions for your specific county extension office), but almost all of us will need to add much more than we currently have to reach the five-percent ideal.

Cover crops, mulch, and leaving seedless weeds and plant roots to rot back into the soil will help, but you’ll most likely need volumes of cured compost as well. Buying in bulk from local landscape services or nurseries costs about half or a third as much as buying bags from a store. Plus, it’s delivered right to your place. Call and ask around, and you’ll find great sources near you. Keep adding every year, and your garden will improve immensely with each addition—likely more than you can currently hope to dream!

One Major Added Benefit

Over years of reading books on garden diseases and plant deficiencies and their solutions, I noticed a trend: One can delve into an almost bewildering array of complicated methods with varying results and negative unintended consequences, or one can simply add curred compost. Almost every garden plant disease, problem, or deficiency is solved by adding cured compost. It’s almost as if that’s what plants want or something.😉

Beyond being rich and full of organic matter, however, the soil must also be well drained.

1. _{Again, one could argue that being rich and full of organic matter are one and the same, but a soil could have plenty of organic matter but be poor in nutrients—many swamp and marsh soils are exactly that—and soil can be rich, mainly from added short-term synthetic fertilizers and have very little organic matter.} ↩︎