Cinder Blocks Make Great Container Gardens — Here's How to Use One As a Garden Bed (2024)

Equipment / Tools

Materials

How to Build a DIY Cinder Block Garden Bed

First choose a patch of ground for your garden bed that gets enough sunlight during the day for what you’re hoping to plant. You’ll also want to be close enough to a water source, or at least within the length of your garden hose so that you can keep your new garden hydrated.

1. Calculate the Dimensions

   A typical cinder block is 8 x 8 x 16 inches. Let's figure out how much a 4 x 8 garden needs.

   Length:
   8 x 12 = 96 inches
   96 / 16 = 6 cinder blocks for one side of the bed
   6 x 2 = 12 cinder blocks for the long edges of the garden

   Width:
   4 feet = 48 inches
   48 / 16 = 3 cinder blocks
   3 x 2 = 6 cinder blocks for the short edges of the garden
   

   Garden Bed Perimeter:
   12 + 6 = 18 cinder blocks

   Modify the math to meet your own desired cinder block garden bed size.

2. Mark Off the Area

   Use wooden stakes to mark off the edges of your bed, then tie a length of string or thin rope to the Stakes to mark off the perimeter of the bed.

3. Prepare the Ground

   Assess the ground in your area to determine how to prepare it for the bed. Remove grass or do some digging to flatten out the existing soil for planting, as needed.

   Put down a layer of landscaping fabric before laying your cinder blocks and filling in with soil for improved weed control.

4. Arrange the Cinder Blocks

   Place the cinder blocks on the perimeter with the openings facing up. This will serve as the border of whatever soil and mulch you’ll be filling it with, so you don’t want cinder blocks to be tilted, uneven, or have gaps between them.

5. Add Another Layer of Blocks (Optional)

   Depending on the aesthetic you prefer, you may stack your cinder blocks for a bed with higher edges (in which case you’ll need to double the number you calculated).

   While the cinder blocks are hefty, you’ll still want to secure them on top of each other. Place a wooden stake or a piece of rebar through the holes of the first layer of cinder blocks, then place the second layer over them so the stake is threaded through the openings of the cinder blocks. Filling them in with dirt secures them further.
   

   Tip

   Consider what types of plants and flowers you plan to grow when you decide the height of your bed. Small plants will be more visible with a shorter border, whereas taller plants will grow up and over the border easily. Some plants may require more room for their roots to grow.

6. Fill Perimeter With Dirt

   Fill the perimeter of the cinder blocks (i.e., the openings in the blocks) with dirt and/or mulch. To keep the cinder blocks firmly in place, you can fill the holes with soil as well—that also creates spots for additional plantings should you choose to garden in them.

7. Fill With Topsoil and Plant

   Fill in the center of the bed with topsoil. Now that you've done the work, you can plant any flowers, plants, herbs, and vegetables you desire and enjoy your new garden.

What to Grow in a Cinder Block Garden Bed

You can grow just about anything you want to in a cinder block garden, provided you’ve got the right amount of sun exposure.

That said, you will want to consider the overall aesthetic of your garden, including how tall your plants will grow. Keep in mind that a typical cinderblock is 8 x 8 x 16 inches, so you’ll have an 8-inch high border with a one-layer perimeter, less any topsoil you add to the interior. Assuming you want to see your plants from a distance, you’ll want to choose plants that grow higher than the border.

Here are some choices for quick and easy plantings right inside those cinder block openings:

• Marigolds (good for keeping out insects and other garden pests)
• Herbs
• Strawberries
• Lettuce
• Beans

Any hardy plant that will thrive in a tight space can be planted in the openings of a cinder block. You could simply fill the holes with topsoil and plant, or you might even consider fitting small potted plants in the holes instead for easy swapping/repotting later.