by Karen O’Rourke, Goodhue County Extension Master Gardener
“Keyhole Gardening” by G. Elaine Acker in Texas Power Coop’s online magazine inspired me try a 3-D keyhole-style garden in the Spring Creek Community Garden. This style of garden is another “no-till” garden method. It is built on top of existing soil on a site receiving 6-8 hours of sun per day.
I modified the keyhole garden concept because it is in the Red Wing Sustainability Commission’s plot. If it were at my home, the outer walls would have been made from brick, stone, recycled concrete or a more permanent material. At the Spring Creek Community Garden, I used 13 bales of barley straw, supposedly “weed-free”, from Sargent’s Nursery.
Bales were placed in a modified circle, two bales high to reach approximately 36″ with an inside diameter of 6′ (and, yes, I did have my trusty measuring tape out). Wooden stakes were driven through the straw bales to help them through the summer. A “wedge” was made into the circle for a path to easily reach into the tower.
Inside the circle, I placed a 4-foot tall and 1-foot wide chicken wire compost tower supported by three stakes. This tower or basket, has alternating layers of wood chips, weeds, old hay, composted cow manure, (Cowsmo from Sargent’s Nursery) and will also contain kitchen waste, leaves, debris from the gardens as the summer continues. It will be watered thoroughly throughout the summer and the plant roots will gravitate toward the tower to seek moisture and nutrients. Little watering will be done in the area around the tower.
The inside of the straw bale circle around the tower also contains layers of old hay, shredded bark, Cowsmo, cardboard from the recycling center, weeds, etc. with several inches of compost from my composter located in the Master Gardener’s plot, and more Cowsmo – similar to the “lasagna” approach found online and in a book by the same name available at the Red Wing Library.
What is the purpose of the keyhole garden? This garden method can:
- Save soil structure by avoiding tilling
- Use recycled materials to create new humus or soil
- Reduce water use
- Provide nutrients for the polyculture of vegetation planted in the soil
Historically, the keyhole garden came from Africa and has become popular in drier areas of the U.S. Debra Tolman, a landscape architect from Texas, has several articles, photos and YouTube videos of keyhole gardens – just search online under her name or “keyhole gardens”.
Next time you are out to Spring Creek, please do wander over to the straw bale structure in the rear of the garden to view this process. It will be as new for you as it is for me.