Coffee Grounds for Compost and Soil
Using coffee grounds compost and soil to build a new garden bed from scratch is one of the most satisfying things I’ve done in the backyard. I’ve written in previous posts about the joy of creating new soil, most recently in the one New Soil in the Making. The focus of that post was that by using a variety of compost bins and other methods, we can turn kitchen scraps and other organic matter back into soil, which is what our plants need for survival. No soil, no micro organisms, no life.
Seeing how I use coffee grounds in the compost bins, the thought occurred to me that we just might be able to combine it with dirt from around the side of the house (you know the dry sandy nothing grows in it type), along with leafmould, and a few chicken carcases dug in about a foot or so. This is what it now looks like, having been left to rest since Winter began, several months ago.
This is the area in question.
And the wide shot
A scrape of the top layer reveals the grounds, leaves and twigs.
A coffee cake has survived intact. There were a few of these still lying near the surface, but notice how there is no mould on it. Looking through the others, all the wet soaked through cakes were mould free, and the dryer ones below the top layer were showing greater signs of decomposition.
Removing the top layer to expose new soil in the making. It also carried that earthly smell. A combination of leafmould and coffee. Very nice just to sit there and think of nothing else.
And how could I miss out on the close up!
And a few of these little guys. If the worms are there, it’s a good bet that the other required organisms are there also. Everything from bacteria to fungi to centipedes and spiders. The worm population here is a strong sign that the coffee grounds compost and soil mix is working. If you want to go further with worm-powered composting, the process of making soil with worms is worth exploring in its own right. And look how romantic we have matching rings.
Now running some pH tests on samples of the soil. The outer purple sections are dye stains applied to the soil and paper napkin. The greenish sight in the middle is the result of dyed soil with barium sulphate on it. The colour represents the pH level.
Image from sample 2.
Now looking at sample 1 again with the matching chart. In trying to find the appropriate match it seemed to sit around the 6pH level, which is not a problem for most plants and vegetables as is, and as it breaks down further should move increasingly to alkaline pH.
So as you can see, I have the power of new earth in the palm of my hand (queue evil laugh). Seriously though, a very satisfying thing to do, this thing with coffee grounds in the garden. If you are trying to improve poor soil, the approach of mixing coffee grounds compost and soil with leafmould and organic matter is worth the patience it takes. You might also find it useful to think about how coffee grounds in potting soil behave differently to an open garden bed situation. If you are composting soil but nothing grows, try some of the things covered above.
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