DIY: How to Build a Sturdy and Drainable Garden Bed Using Lava Fines and Cinder Blocks

July 17, 2023

There is something particularly rewarding about rolling up your sleeves and getting your hands dirty in your own garden. And at APC Construction, we understand the joy that comes from creating a personal garden space that looks and functions the way you want it. That’s why we’re sharing a unique DIY project – building a sturdy, drainable garden bed using lava fines and cinder blocks. 

Lava fines, with their excellent drainage properties and nutrient-rich content, paired with cinder blocks’ durability, make for an excellent and efficient garden bed. Let’s get started! 

Here’s a list of materials you’ll need to start with: 

  • 24 cinder blocks (standard size: 8”x8”x16”) 
  • About 4 cubic feet of lava fines
  • Compost and topsoil 
  • Weed barrier 
  • Gloves and safety goggles 

1. Prepare Your Area 

Choose a sunny, flat area in your garden. Clear any debris and grass, leveling the ground to ensure a stable base for your cinder block bed. The size of your bed will be determined by the number of cinder blocks used. A standard size is 4×4, using 24 blocks. 

2. Lay Your Cinder Blocks 

Start by placing your cinder blocks in your chosen design, ensuring each block is level. The holes should face upward. This creates a neat, sturdy perimeter for your garden bed. Always wear your safety gloves and goggles during this step. 

3. Install the Weed Barrier 

Lay down your weed barrier inside the garden bed, covering the ground entirely. The barrier prevents weeds from growing up through your bed and ensures your plants are the stars of the show. 

4. Add Lava Fines 

Lava fines not only make for great drainage but also keep your garden bed aerated and prevent it from compacting over time. Pour the lava fines into the bed, filling it about a third of the way up. 

5. Add Compost and Topsoil 

Add a layer of compost over the lava fines to provide nutrients to your plants, filling another third of the bed. Then, top up the bed with a layer of topsoil. Your soil should be level with the top of the cinder blocks. 

6. Plant and Enjoy 

Now comes the fun part – planting! Choose your favorite plants or vegetables and start planting. Remember to water thoroughly after planting, and regularly afterward. 

Building a cinder block and lava fines garden bed is a straightforward weekend project that not only enhances the functionality and appeal of your garden but also provides the perfect home for your favorite plants. And the best part? You can tell everyone you did it yourself.