Keyhole Garden History
Keyhole gardens were established in the 1990’s for residents in Lesotho a southern Africa nation that had to deal with frequent drought and soil erosion issues. They had originally been designed for people who suffered from AIDS or were otherwise unable to tend to a traditional garden.
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After my husband retired from the military, we knew we wanted to settle in the high desert region of Northern Nevada. Knowing the area was prone to droughts I began researching ways to be self sufficient in this challenging climate. I found several articles that mentioned keyhole gardens.
The keyhole garden got its name for the unique shape, similar to the old fashioned skeleton-key lock. The garden is circular in shape with a cut in portion to allow access to the center. Within the center is a cage used for compost.
A keyhole garden is a type of permaculture garden because it is sustainable and regenerative. When it is first constructed the keyhole is laid out and built up with stone which will hold moisture in. Then it is layered with compost, manure, wood ash and other nutrient rich materials.
When the composting center is watered the nutrients will spread through the soil providing fertilization. The soil created this way is highly nutritious and allows for more intense planting.
Compost
The compost is a vital key to the success of the keyhole garden. Composting is a great way to reduce the amount of waste you throw in the trash. According to the NRDC food scraps and garden waste make up over 28% of what we toss. Compost is essential to improving our food system.
The compost cage is continually decomposing and releasing nutrients to the surrounding soil. By watering at the center the water drains through the compost and out to the rest of the garden.
There has been research showing that improved organic matter in soil will hold more water.
Keyhole Design
The original design of a keyhole garden was circular with the cut out using stacked stones. Generally, six feet in diameter and stacked two to three feet high. This small sized helped to ensure that you can reach all parts of the garden.
There are kits available now that you can purchase online with a few different options.
The above option is a common design that you can find available. They are easy to construct and this particular model has the compost in the cut in portion similar to a traditional keyhole garden.
This square Urbana model has a sleek design that can be put near a fence or the edge or a yard. In this design they put the compost bin in the middle of the rectangle.
Even though these are raised off the ground if you live in an area that has squirrels or deer you may need to add fencing.
DIY Keyhole Garden
If you plan to build your own garden or use a kit these are important steps to take into consideration.
- Choose a location – level ground, not subject to flooding
- Determine the configuration of the outside wall.
- If you are building a circular garden use a string three feet long to mark the perimeter
- Allow approximately a 24-inch opening angled in toward center for the “keyhole”
- After you have your layout you can construct your garden by stacking stones, bricks or concrete blocks. You can also use corrugated metal, or old fencing just ensure it is strong enough to retain the soil.
- Line the base and lower level with cardboard to block any holes.
- Construct a compost cage using chicken or rabbit wire.
- Place the composting cage near the keyhole entrance of the circle and drop a few inches of stone in. This will help the cage stay in place and provide aeration for the compost.
- Fill or layer the garden. Ensure the top foot is good quality soil .
- Grade top portion of soil to slope away from compost cage so water runs to outside edge.
- Fill compost cage with a mixture or garden waste and kitchen scrapes.
- Plant your garden with your most frequently used produce.
Care and Tips for Long Term Use
Water your keyhole garden in the compost cage. This allows the water to filter down and out through the nutrient dense center.
Add kitchen scraps and other organic matter when you notice the compost has dropped. It can become compact, so you don’t want to add to many things. You can consider adding red wiggler worms to assist your compost.
Each year when you are planting make sure to rotate your crops. Keeping a garden journal can help you keep track of where things were in prior years.
As part of your spring planning examine the construction to determine if any repairs may be needed.
Every three or four year consider cleaning out the compost cage and starting fresh. This old compost can be used in other areas of the yard, but this will help ensure that your keyhole garden is receiving good nutrients all the time.
If you decide to try a keyhole garden, I would love to see pictures. Share your success and stories in the comments.
