The Ultimate Guide to Raised Garden Beds with Built-In Compost Bins

Raised garden beds with built-in compost bins are the perfect solution for gardeners like me who want maximum yields with minimal effort. As an avid gardener and a bit of a lazivore, I’m always looking for ways to make vegetable gardening easier and more productive. After years of experimenting with different techniques, I’ve found that combining raised garden beds with compost bins is the ideal set-up.

Why Raised Beds?

First, let’s look at why raised beds are so great for gardening. Raised garden beds provide the following benefits:

• Improved drainage – The loose, amended soil mix drains better than compacted ground soil. This prevents plants from getting waterlogged.

• Warmer soil – The beds are up off the cold ground so they warm up faster in spring, allowing for earlier planting.

• Easier access – Less bending down to tend to plants, making gardening more comfortable

• Keep pathways clear – Beds provide a designated space for growing and prevent plants from spreading into walkways.

• Different types of soil: You can fill beds with the right mix of soil for the plants you want to grow.

• Space efficient – Raised beds allow you to grow more intensively in a small space.

Adding a Compost Bin

Now, take all of those good things and put a compost bin right inside the raised bed frame. In this system, your garden feeds the compost and the compost feeds the garden, making it work well together

Here’s how it works:

The key is to construct a raised bed in the shape of a circle, rectangle or square with one side left open. This open side will be your access point to periodically turn and harvest finished compost.

If you want to make your own raised bed, I like using rot-proof cedar planks and galvanized screws to hold them together. But you can also use masonry blocks, bricks, or decorated steel frames.

Size your raised bed based on your available space, gardening needs and how much compost you anticipate producing. A good rule of thumb is making your compost bin area about 1/3 the total size of the bed. For example, a 4 ft x 8 ft raised bed would have a compost bin taking up about 4 ft x 2 ft inside the bed frame.

Composting Basics

The key to any compost setup is providing a balance of “greens” and “browns” along with adequate moisture and oxygen circulation. Greens refer to fresh, nitrogen-rich materials like vegetable scraps, grass clippings and coffee grounds. Browns refer to dried, carbon-rich materials like leaves, straw and shredded paper.

To build your compost pile inside your raised garden bed, start by putting down a 4-6 inch base layer of coarse browns like sticks or branches. This allows for airflow from the bottom.

Next, add a layer of greens and browns in equal amounts, about 6 inches deep. Alternating greens and browns will give you the ideal carbon-nitrogen ratio for composting.

Repeat this layering process until your compost bin area is full. Water the pile as you build it so that it has the moisture content of a wrung-out sponge. Avoid compacting the pile too much – you want lots of air pockets for proper aeration.

Place a lid or cover on the compost section to retain heat and moisture. This will help kickstart the decomposition process. Leave an access point uncovered so you can periodically mix and add new materials.

Maintaining Your Raised Bed Compost Bin

Turning or mixing your compost pile weekly will help speed up the breakdown of materials. Using a garden fork or compost aerator tool, lift and mix up the pile from the bottom and edges towards the center. This distributes moisture, eliminates anaerobic pockets and restarts the heat-generating microbial activity.

Monitor the moisture levels in your compost as you turn it. Compost should always have the dampness of a wrung-out sponge. If it ever appears dry, add water as you mix.

Chop or shred any new materials before adding them to your compost pile. The smaller the pieces, the faster they will break down.

Avoid adding pernicious weeds, diseased plants, meat scraps or pet waste which can contaminate your finished compost. Stick to veggie scraps, leaves, grass clippings and other basic garden materials.

Within 2-4 months, you should have finished compost ready for harvesting. It will look dark, crumbly and earthy-smelling when ready.

Feeding Your Garden Bed

Here’s where the real magic happens. As your compost pile breaks down, all those nutrients created will leach directly into the soil of your raised garden bed. This enriches your planting mix naturally, right where it needs it most.

Periodically, remove mature compost from the bin area with your garden fork. Screen this “black gold” to remove any unfinished woody pieces and work it into the top 6 inches of your raised bed’s soil.

Replenish the compost bin with a fresh batch of layered greens and browns. By the time your current garden plants are spent for the season, your next round of compost will be ready to feed a new crop planting. It’s the perfect cycle!

Growing Materials for Compost

Another trick is using your garden beds to grow organic materials that you can compost, like cover crops and leafy greens. Here are some easy crops to grow “compost ingredients”:

• Cover crops like clover, vetch and rye add nutrients when tilled under the soil.

• Lettuces and spinach provide plenty of nitrogen-rich greens.

• Prolific self-seeding plants like arugula and cilantro will regrow all season long.

• Straw from grains like wheat, rice and buckwheat gives you carbon-rich material.

Compost Bin Tips and Tricks

Here are some helpful tips for successfully managing your raised bed compost bin system:

• Use wire mesh screens or pallets to create separate compartments if turning the entire pile becomes too difficult.

• Keep a bucket next to your raised bed to collect scraps for compost as you garden. No need to walk back and forth.

• Keep a supply of coarse browns nearby to cover fresh greens and keep odors down.

• Use a compost thermometer to check if your pile is heating up properly. Internal temperatures should reach 130-150°F.

• Try compost tea: Steep mature compost in water to create a nutritious fertilizer for your plants.

• Plant heat-loving crops like tomatoes, peppers or herbs around the edges of your bed to take advantage of compost heat.

Troubleshooting Problems

• Bad smell? Your compost needs more air circulation. Turn the pile and add coarse browns.

• Pile doesn’t heat up? It’s too dry. Add water while turning.

• Ammonia smell? Too much green material. Add more browns.

• Takes too long? Shred everything smaller and turn pile weekly.

• Critters getting in? Add wire mesh underneath and over the compost.

Choosing a Raised Garden Bed Kit

For the ultimate lazy gardener convenience, you can purchase a raised bed kit that includes the integral compost bin right in its design. Look for one like these:

• The Frame It All Slim Jim Composting Raised Bed Garden Kit is a 3’x6′ cedar bed with removable front slats to access the built-in compost bin.

• The Algreen Arch Raised Garden Bed is a round raised bed with an open center compost area.

• Keter’s Urban Garden Composter sits inside the bed frame and can be rotated for compost harvesting.

With one of these kits, you’ll have your raised bed compost bin system ready to go without any heavy construction. Just add soil and start layering in the compost materials as outlined above.

If you’re looking for an almost effortless composting method, a raised garden bed with an integrated compost bin is the way to go. Your plants will thrive with this nourishing, recycling system right at their roots. Try it this year and see how your garden grows!