Keyhole Garden Explained: How to Build Keyhole Garden Beds

A keyhole garden is a raised bed that incorporates a cutout near the center of the bed. This center basket area acts as a compost pile to break down organic matter into mulch. You can then use this collection of compostable materials to replenish nutrients in your garden soil. Farmers from Lesotho, a country in Southern Africa, developed this permaculture garden design to recycle food scraps and amend poor soil. The idea has since spread, and now farmers in arid, drought-prone climates, such as in India or Texas, can benefit from this low-maintenance, sustainable gardening strategy.

Follow these simple steps to build a DIY keyhole garden with raised beds and a central section where you can add nutrients to the soil:

1. 1. Choose a location for your keyhole garden. A typical keyhole garden has a medium footprint, so you might find it’s easy to incorporate into your existing landscape design. If you plan to grow radishes, beets, or any other full-sun vegetables, you can choose a location near the center of your property, away from tall trees and shade.
2. 2. Place a compost bin in the center. You can use chicken wire and twine to form a cylinder in lieu of a traditional compost bin. This inner containment area at the center of the garden footprint will allow adequate airflow to reach the kitchen waste and break the waste down into a nutrient-rich mulch.
3. 3. Build a retaining wall around the perimeter to hold the garden soil in place. You can build the outer wall of the raised garden bed with any material that is sturdy enough to hold the topsoil in place. Cinder blocks, bricks, or large river stones are all excellent materials that will hold their stability at round or abrupt angles.
4. 4. Add drainage material to the bottom of your garden. You can add gravel, twigs, cardboard, or wood ash at the bottom layer of the garden. This drainage layer will decrease the leaching of nutrients into the native soil below. Proper drainage will also maintain airflow in the top layer of the garden and decrease the chances of root rot early in the growing season.
5. 5. Place vegetable scraps and other organic material in the center compost basket. After you have placed your drainage layer, you can add a layer of soil, followed by a thin middle layer of organic material, such as grass clippings. The organic material will break down and release nitrogen into the soil, expediting the mulching process at the center keyhole.

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