I learned some wonderful strategies for working with caliche layers under poor soils from the local gardening community. Keyhole gardens are one of the approaches. I have seen several interpretations of the keyhole garden posted on Facebook. Then some Julie Jensen shared a cool article posted by InspiratonGreen.com on Facebook. I have been wanting to reblog existing information on key hole gardens prior to introducing a modified version that I have been working with in my yard. So, big thanks to Julie for getting me started. The link to Inspiration Green’s article is http://www.inspirationgreen.com/keyhole-gardens.html.
In arid regions, the native soil often has little organic matter and can be unworkable most of the year. Frequently desert soils are great for making bricks, but not so wonderful for farming and gardening. When tilling native soil isn’t practical, building new soil on top of the existing ground becomes an attractive option. High desert gardeners employ a number of strategies for doing this. One of them is use of keyhole gardens.
These radial gardens feature a compost column surrounded by a raised bed bordered with rocks, bricks, or some other material. The raised bed is created by layering organic matter and soil over branches or rocks surrounding the compost column. A path the the compost column is at ground level. For a schematic of the basic design, see Keyhole Schematic Link.
Numerous High Desert Gardeners have posted pictures of their keyhole designs on Facebook. These gardens range from very simple and rustic to downright elegant landscaping features. Cinder block bricks appear to be the most popular border material in the High Desert. Check the following groups for pictures of keyhole gardens: Gardening in the High Desert, High Desert Garden Junkies, and High Desert Vegetable Gardens. These are closed groups moderated by local gardeners, so you may need to join the group to see posts. Keyhole Gardens, Permaculture California and Master Composters-Mojave Desert/Mountains are a public groups.
Additional Links to Posts or Articles on Keyhole Gardens
Valhalla Project. From Africa to Valhalla: a keyhole garden. by Chris. January 1, 2012.
Goodhue County Extension Master Gardeners. Keyhole Gardens. by Karen O’Rourke, Goodhue County Extension Master Gardener. June 8, 2013.
Total Landscape Care. How-To: Keyhole gardens can work anywhere, beautifully. by Jill Odom. October 8, 2015.