What is a Keyhole Garden?
Raised bed gardening is my favorite way to garden. I love the ease of set up, and harvesting is a snap and, if you set your beds upright, there is little weeding to be done. Making a keyhole garden uses all these concepts and more!
Raised beds are nothing new. The idea is to elevate the garden to maximize drainage, improve the soil, and enhance access. Keyhole gardens are a riff on that idea, with one addition: a center compost area that works as a self-fertilizing element for the plants. A salad keyhole garden takes it a step further, by planting specific vegetables and herbs together–to be picked at the same time–to create a delicious dish.
What’s most interesting about keyhole gardens is their bountiful history.
They began as an invention of charitable organizations to help people in developing countries create a self-sustainable, controllable food source. Considering that the construction of keyhole gardens often utilizes recycled materials – think cast-off tin and upcycled bricks – schools in some of those countries use the gardens as a way to both grow nutritious ingredients for school lunches and as a learning tool, for children to take the idea home to their parents. The center compost bin serves a dual purpose: it provides nutrients to the plants and offers a spot for recycling kitchen waste.
One of the biggest attractions of a keyhole garden is its ease of construction. Nearly any material that will withstand the stressors of weather–rock, stone, bricks, metal–will work for the walls. Although there’s no right or wrong height, a keyhole garden typically maxes out at about 6 feet wide, but smaller diameters will work well too. The access notch makes the garden look like a keyhole, and leads to the composting center. That’s often placed on the least sunny side of the bed (usually north), to allow the plants to capture the sun better.
Read the full article with instructions on how to construct your very own keyhole garden HERE
How to Make a Keyhole Garden
Follow these step-by-step instructions to start keyhole gardening.
- Gather materials like bricks and rocks to make a circular wall with a diameter of 6 feet and a wall that measures 3 feet in height. This is the key concept to a keyhole garden design.
- With the help of chicken wire, make a tube that will serve as the compost bin. Place the tube at the center of the keyhole garden.
- Then, take a small section of the outer wall and to form two walls that run to the compost bin at the center. You’ll get the keyhole shape.
- Afterward, take some things off your compost piles such as cardboard and other recycled materials of the same nature then layer them in the walls and bottom of the garden bed. Above the layer of cardboard, add organic matter such as grass, plants, twigs, and other compostable materials. Lastly, the top layer should of good soil and other composting components. The soil must slope down to the center from the compost bin. This serves as your keyhole composting garden bed.
- Continue to fill the compost bin with food scraps like vegetables, coffee grounds or other stuff that can also be considered as kitchen scraps. You can research for more what goes inside the compost bin to make your keyhole garden kit complete.
- After a few months, the garden soil may drop so you can add more.
- Last but not least, start gardening. Gather your plants or basket of seeds and other essential elements in gardening such as rocks and water.
What Plants Do Well in a Keyhole Garden?
All kinds of plants can be planted in a keyhole garden. But, the best plants would be root plants such as carrots, beets, radishes, and leafy vegetables like spinach, lettuce, and herbs. The nutrients and enough water supply would allow them to grow healthy.
Crops Not Recommended For a Keyhole Garden
Sadly, not every type of plant is going to do well in a keyhole garden. While that doesn’t mean you can try them, we wouldn’t specifically recommend these crops for it:
Again, that doesn’t necessarily mean you can’t plant these. But do be aware that keyhole gardening isn’t the best growing environment for these crops.
If you’re brave enough, feel free to try planting these and tell us in the comments below how well it worked out for you and if you discovered any tricks to make them sustainable in your particular case. Sharing thoughts and ideas is what makes the community on our website so great.
What Are the Advantages to a Keyhole Garden?
These are the advantages of a keyhole garden.
- It adds nutrients to the soil.
- It retains moisture. When moisture stays longer, it means that the garden requires water less frequently.
- It lessens the labor of gardening. A raised bed allows for more access to older gardeners because raised bed gardening makes gardening easier for planting, weed control, and harvesting. Moreover, moisture retention means you don’t have to water your plants every day, thus less effort.
- Low-cost design
- Vegetable production all year round
How to Maintain a Keyhole Garden
First off, don’t forget to regularly water your keyhole garden so that the soil remains moist.
Make sure to use clean water on the top soil as to not contaminate your plants. Pour water from washing hands, laundry, or dishes into the basket. The thatch and the composting in the basket will clean the water.
Speaking of soil and water intake, make sure to replenish the top soil and dry manure regularly in the garden so that it does not become sapped of its fertility. As for replenishing the soil, you can add uncooked vegetable scraps, dry manure, eggshells, and compost.
Also, the basket will decompose within 1 or 2 years and should be replaced. You can pull away the garden wall near the basket for easy replacement. The garden will lose nutrients over time and vegetables will stop growing well. That is why it is important to completely rebuild the entire garden once every four or five years.
Final Thoughts on Keyhole Gardens
Get other companion planting ideas from one of my favorite new books – The Mix & Match Guide to Companion Planting, learn about other Permaculture Principles to use in your yard, and review other Drought Buster Strategies.
Have you used the Keyhole Garden concept in your yard? Share your successes (and failures) with raised bed gardening in the comments below. It’s what makes the community on our website so great.