Raised bed gardening can be combined with composting to give you the benefit of healthy plants and sustainable waste disposal with the help of something called a ‘keyhole garden’. A round, raised garden bed with a notch in the center allows gardeners to deposit organic matter into the center pit in the bed to break down and create wonderful compost.

Keyhole gardening incorporates in-ground composting into your garden so the nutrients go directly into the soil you’re growing in. I’ve thought about building my own keyhole garden, but have always been a little intimidated by the project. Then I saw that Costco has 4’x4’ pre-made keyhole garden beds for sale. Sign me up!

I love that you can throw leaves, kitchen scraps, plant prunings, and other yard waste right into the composting section and let the garden go to work for you. It is so simple and it is perfect for my backyard raised vegetable garden.

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Why Use a Keyhole Garden?

Keyhole gardening is a technique that was developed in Africa to help address low soil fertility. It is a compact and efficient way to garden that increases soil fertility and health and it has become popular in the U.S., too. Keyhole gardens are essentially raised beds and in-ground composters in one.

The Vita keyhole composting bed from Costco is a great entry point for curious gardeners looking to improve their soil and boost their plants. You can use a keyhole garden for vegetable beds, ornamental beds, cut-and-come-again flower beds or anything you choose. This innovative method of gardening makes it so you don't need to fertilize to get the garden of your dreams. You also won’t ever have to lift a pitchfork to turn compost again.

Composting in your keyhole garden can reduce household waste by up to 30% and all the energy from food scraps and yard waste gets transferred directly into your garden. I especially love that this keyhole garden from Costco uses a BPA and phthalate-free polymer so you don’t have to worry about chemicals leaching into your produce. Compost-fed soil also requires less water since the water from the scraps is being added directly into the bed.

How to Use the Vita Keyhole Garden

The Vita keyhole bed has a generous basket in the center of the bed which is where you will do your composting. Like with all composting, you need a healthy mix of “greens” and “browns.” Greens refer to items that are high in nitrogen like grass clippings, tea bags, kitchen waste like fruit and vegetable peels (no meat, fat, or dairy), and freshly pruned plant matter. Browns are high in carbon content and can be things like paper, dried leaves, small twigs, saw dust, wine corks (not the rubber kind), and coffee grounds.

When you set up your new keyhole garden, just slide the boards into the posts and set the basket in the center. It requires no tools and comes together super quickly! You can begin to fill in the bed with organic matter like logs, sticks, leaves, grass clippings and even cardboard to help fill it up. Water the layers as you add them to help them begin to break down – it’s just like filling a hügelkultur bed! Then add 6-8 inches (15.2-20.3 cm) of top soil to finish it off.

You can plant your garden and begin adding compostables to the central basket as soon as it is assembled. Easy peasy!

The Vita keyhole composting garden bed is so quick and simple to get started using and it is virtually maintenance free. I also love that it comes with a 20-year warranty for material defects, and Costco is also known for standing by their products and superb customer service.

I can’t wait to get started on my own keyhole garden!

More Keyhole Gardening Setups