At the Manna Soup Kitchen Garden, we didn't necessarily start out with rich, fertile agricultural soils or really anything that you might identify as soil. We are blessed with shale, shale, and more shale. As many gardeners in Durango know, shale is not a valued resource for yards, gardens, or urban farms. So you might be getting the picture here that our growing medium was less than adequate for the production of vegetables and fruit trees. If you have the same issue, which you very likely do if you live outside of the animas valley in Durango, there is a way to grow in this landscape.
The key to growing here lies in building your own soil. This is a long term investment and certainly won't pay off instantly so consider your methods of growing soil as your garden savings account. Our path for growing in this area is outlined below:
- We dug out 2 to 3 feet of shale in order to replace it with soil - the shale should be thought of the same as a pile of rocks, similar to landscaping gravel, granite, or rockfall
- We built raised beds on top of the dug out areas, ultimately creating around 3 to 4 feet of soil
- We added a purchased "vegetable blend" of amended topsoil and filled all of our beds, this gives us a good starting point
- We set up a worm farm and compost pile to start creating our own soil amendments and fertilizer for the future of our garden
- We are planning on planting a couple rounds of cover crops like inoculated fava beans or field peas in order to start adding nitrogen to the soil, We will also heavily mulch these areas to keep the soil moist to promote decomposition. Throughout the summer we will add worm castings as they are produced.
- In the fall, we will add our finished compost that contains a mix of manure, "green"organic materials, and "brown" materials. We are carefully watching our compost temperatures to ensure that the piled is aerated at the proper times to encourage a pile that is ready for the fall
With our expansion of the garden further into the shale reserves, we will continue to build soil for our existing and future garden beds. Our compost pile is a windrow located on the south side of our garden. We added some compost chimneys in order to create some convective air flow. The chimneys are made of PVC pipes with many holes in them, ideally the pile should suck cool air from bottom as the trapped hot air rises. Aeration speeds up the decomposition process (hence turning the pile creates more heat once the temperature has lowered). This chimney method should provide air without us having to turn the large windrow.
Please feel free to share any experiences that you have all had growing in the shale! This is our common challenge here in Durango.