How to Build a Vegetable Garden Cinder Block Raised Bed

The spot had never been gardened before and was covered in weedy grass. My hard-working husband tilled and raked and tilled and raked until the area was clear. We tried to work the soil a bit, but it was clear right away that it would take a lot of work to even half-way decent the heavy clay soil.

If we wanted to garden any time soon, we would need another option. Many thoughts were given, but the best choice was to build raised beds and fill them with healthy soil.

Before, we built raised beds with wooden frames, which worked fine. But wood gets old, and we wanted to make something that would last a very long time.

So we chose concrete blocks. They can break if they’re dropped hard or hit by heavy machinery, but overall, they’re very strong, and most of them will probably last longer than us. .

Since the blocks are about 8 inches by 8 inches by 16 inches, you can move them around to make beds wherever and however you want (no special tools needed). It’s certainly hard work. Putting together the garden you want is possible with the blocks, even though they are heavy and you have to move the dirt around.

If you live somewhere that freezes really hard in the winter, you will probably have some frost heave. (The soil pushes up during freezing conditions. ) What that means practically is that you will have to adjust a few bricks come spring. With a hand shovel, move the brick back into place by rolling it over and adding or removing soil.

Cinder block raised beds offer an affordable and durable way to grow vegetables and flowers. The hollow blocks are easy to assemble into customized beds of any size or shape to fit your space. Filling them with rich soil gives plant roots the nutrients they need while improving drainage. Follow these simple steps to create your own cinder block raised bed for a productive vegetable garden.

Benefits of Raised Beds for Vegetable Gardens

Constructing a raised planting bed for vegetables has many advantages over growing directly in the ground

Improves drainage in heavy or compacted soil
Allows control over soil quality by filling with amended planting mix

Extends the growing season by warming soils earlier in spring
Reduces weed pressure and eliminates soil compaction from foot traffic
Raises plants to a comfortable working height, reducing back strain

Defines neat planting areas, keeping plants organized
Provides good drainage and aeration for healthy root growth

Why Use Cinder Blocks for Raised Beds?

Cinder blocks offer an affordable, durable material for building raised garden beds. Here are some of the benefits of using cinder blocks:

Inexpensive and widely available
Sturdier than wood, won’t rot or warp

Each block has built-in planting pockets
Easy to construct, rearrange, or expand beds later
Provides some frost protection for plant roots

Can support greater soil depth than traditional beds
Permits better drainage and air circulation to plant roots
Block interiors can be filled with soil or compost

Planning Your Cinder Block Garden Bed

When planning a cinder block raised bed, first decide on the location. Choose a level, sunny spot with good drainage. Check that water doesn’t collect after heavy rains.

Decide on the size and shape of your raised bed. Rectangles or squares work well for efficient use of space. Limit your reach to 3 feet across for easy access. Bed width can be adjusted based on the length of your cinder blocks.

For example, standard 8″ x 8″ x 16″ cinder blocks will give you a 32″ wide bed when placed in pairs along the length of the bed. Arrange blocks in the planned shape before filling to ensure proper alignment.

Building Your Cinder Block Raised Garden Bed

Follow these simple steps for constructing a raised bed from standard cinder blocks:

Step 1: Define the Bed Area

Mark off the shape and perimeter of your planned raised bed with stakes and string.

Remove any grass or weeds inside the bed area.

Step 2: Level the Ground

Ensure the soil surface is as flat and level as possible where the blocks will be placed.
Add or remove soil as needed to level the ground.

Step 3: Arrange the Blocks

Place cinder blocks directly on the soil in your planned layout without mortar.
Check with a level and add or remove soil beneath to stabilize any wobbly blocks.
Optional: Leave a gap every few blocks to allow drainage.

Step 4: Fill Blocks and Bed

Shovel good quality planting soil into each cinder block, filling the holes.
Fill the interior bed area with soil up to 1 inch below the block tops.
Avoid compacting the soil; leave it loose for good drainage.

Step 5: Plant!

Your raised bed is ready for planting. Sow seeds or transplant vegetables and herbs.
Add soaker hoses or drip irrigation if desired to easily water your new raised bed.
Mulch around plants to conserve moisture and suppress weeds.

Cinder Block Raised Bed Soil Mix

The soil mix used in a raised bed is key to growing healthy, productive plants. Avoid using heavy native soil which can drain poorly. The ideal mix is:

1/3 compost, leaf mold or peat moss – improves moisture retention

1/3 coarse sand or perlite – creates loose texture for drainage
1/3 topsoil – provides nutrients for plant growth

Mix in a balanced organic fertilizer when filling the bed and replenish annually. Mixing in worm castings or compost provides nutrients plants need.

Plant Spacing for Vegetable Raised Beds

By growing in raised beds instead of rows, you can increase yields while making the most of your growing space. Here are some recommended plant spacings for raised bed vegetable gardens:

Leafy greens like lettuce, spinach – 4-6 inches apart
Root crops like radishes, carrots – 2-4 inches apart
Bush beans, peas – 2-4 inches apart

Peppers, broccoli – 12-18 inches apart
Tomatoes – 18-24 inches apart
Melons, squash, cucumbers – 18-24 inches apart

Onions, beets – 3-6 inches apart

Stagger plantings in blocks instead of rows. Intercrop quick-growing vegetables between slower-developing ones.

Caring for Your Cinder Block Garden

Ensure beds receive at least 6 hours of direct sun daily.
Water when soil dries down 1-2 inches below surface; use drip irrigation to conserve water.
Weed weekly to prevent competition for nutrients and water.

Replenish soil nutrients each spring by mixing in 2-3 inches of compost.
Watch for pests like slugs, snails or aphids and take action if populations increase.
Cover beds with fabric row covers to protect from frost or pests as needed.

Customizing and Expanding Cinder Block Beds

Part of the appeal of using cinder blocks is the ability to easily make changes down the road. To expand the footprint of your garden, simply add more blocks in the desired shape.

For a taller raised bed, stack additional blocks on top of your existing layout and fill with soil to the desired height. Cap the top rows with concrete caps or patio stones for a finished look.

Leave gaps between certain blocks when constructing the bed for convenient access points later on. Pathway blocks can be incorporated to create walking spaces between beds.

With cinder block raised beds, you can grow an abundant vegetable garden tailored to your unique space. Follow this simple process and soon you’ll be harvesting fresh produce just steps from your kitchen!

No More Sore Knees

Another plus is that concrete block beds can be built to a greater height for easier gardening. We are in our 60s, and we want to garden for the rest of our lives. Having a taller edge we can sit on is a plus.

For now, our garden beds are only one block high. But we plan to add one or two more levels with top pavers so we can sit on them while we work in the beds.

Also, we learned the first spring that the concrete blocks soak up heat, which helped our garden area melt much faster. Once the sun hit the blocks, the snow melted in a hurry. That’s a real plus in Washington state where we have such a short growing season. Every year, we can get the garden ready pretty early and then wait for the right weather to plant.

Make a Cinder Block Raised Bed

FAQ

Are cinder blocks good for raised garden beds?

There are a lot of options when it comes to the material used to build a raised bed border. Wood is a common choice. Bricks and stones are good options, too. But if you want something cheap and attractive that’s not going to go anywhere, you can’t do better than cinder blocks.

What plants grow well in cinder blocks?

I planted each of these cloves in its own cinder-block hole. Each one will grow into a full bulb. I also planted two bunches of basil, two bunches of cilantro and one bunch of oregano. Each of these grows in its own cinder-block hole as well.

Are bricks safe for vegetable gardens?

Bricks may have been mortared with toxic adhesives. Painted bricks should be avoided because chemicals can leach into your soil. Industrial and specialty bricks can contain harmful elements that can contaminate your soil. It’s best to avoid commercial bricks entirely.

Is cement safe for vegetable gardens?

Cement is an ingredient used to make concrete. That explains why concrete planters are okay for plants. It’s the cement from the concrete mixture that is dangerous for the plants if they come in touch. While using cement and concrete you have to be aware of acid rain as this can lead to dangerous situations.

Are cinder block raised beds a good idea?

Overall, cinder block raised beds are a great way to create a garden in your backyard. They are easy to build, versatile, and affordable. As well, they can provide a strong foundation for your raised garden that can last forever. Cinder block raised beds are great for those who have mobility issues or disabilities.

How to build a garden bed with cinder blocks?

Build the supports for your raised garden bed with the cinder blocks. Make sure to leave enough space between each wall for storage. Then, place wood planks or even a full box on top of the walls to finish the raised bed. If you don’t use a full wooden box, you can place individual cinder blocks on top for your plants.

Should you build a cinder block garden?

Also, keep in mind that the soil in your raised bed will settle over the first few days and weeks, so you may need to add more to fill in the holes and spaces. If you’re looking for a cheap and easy raised bed project, then building a cinder block garden is the perfect project for you.

How do you build a raised cinder block garden?

The quick-and-dirty way of building a raised cinder block garden is to arrange the blocks, fill in the perimeter with dirt, and start planting. But there’s a little more to it if you want it to thrive and look beautiful, too. Here, we’ll walk you through how to create a four-by-eight-foot cinder block garden bed.