Building a Raised Flower Bed Using Cinder Blocks

Cinder blocks are an easy way to build raised beds.

For an economical way to landscape, consider building a raised flower bed using cinder blocks. Not only will you create a quick and easy place for your flowers to bloom, you can save significant money over traditional flower bed materials. Whether you are an expert gardener or just a beginner, a cinder block flower bed will get you gardening in no time.

Planning Your Flower Bed

Before starting to lay the cinder blocks, you must first decide where the beds should go. If you want a symmetrical look to your beds, measure the block you are going to use so will know how many blocks to buy. Use a garden hose to outline the area you wish to plant, then calculate how many blocks it will take to create the frame. If the flower bed is going to be built next to your home's foundation, there is no need to place blocks on all four sides. Instead, buy enough cinder blocks to frame three sides and let the foundation form the fourth. This saves time, money, and space. Also, decide how high you want your raised flower bed to be. Most raised beds are typically six to 12 inches tall so a single layer of standard cinder blocks, which are eight inches tall, should be sufficient.


Once you measure and calculate the number of cinder blocks you need, make a list of the other items required. Buy a roll of landscape fabric to reduce the amount of weeding later and purchase small pebbles or sand to fill in the cinder block holes. The soil in raised flower beds warms faster than soil in traditional beds but it also has a tendency to dry out faster.

If your planned flower bed is large, you may want to incorporate a drip hose system to keep the flowers looking their best. Peat moss is a good material to use with your potting soil because it helps retain moisture. When mixed with potting soil and peat moss, composts such as cow manure, mushroom compost and worm casings help give your plants the necessary nutrients to grow into healthy plants.

Building a Raised Flower Bed Using Cinder Blocks

  1. Remove any debris from the area where your raised bed will be. If grass is currently growing, use a shovel to dig approximately six inches into the soil and remove the sod. Clear the entire area of grass, weeds, and rocks then smooth the soil with a rake.
  2. Place the first cinder block with the holes facing up then tamp firmly with a mallet so the base is approximately an inch deep in the soil. This will help keep the blocks stable once the soil and plants are added. You may want to use a level as each block is placed so the entire frame remains symmetrical. Repeat with each cinder block until the outline is formed.
  3. Fill in each hole with gravel or sand so weeds will not grow through. Measure the inner outline and cut the landscape fabric to match. Lay the fabric in the bed before adding soil materials. This will deter weeds or grass from growing up through the bottom of your bed.
  4. Dump alternating bags of potting soil, peat moss, and compost into the raised bed until it the material is nearly level with the top of the cinder blocks. Mix thoroughly using a shovel, then smooth flat. If you plan to add a drip irrigation hose, dig a small trench and add it now. Cover the hose with a thin layer of soil material then smooth again.
  5. Add seeds or plants as desired then water well. Check often during summer months to ensure the plants have enough water and fertilize as needed. If the plants you used were annuals, pull any remaining stalks at the end of the growing season and plant again in the spring. If you used perennials, consider adding a layer of mulch to keep them from damage during the winter months.

Other Cinder Block Suggestions

Now that you know building a raised flower bed using cinder blocks is not that hard, perhaps you should try your hand at using cinder blocks for other areas of your landscaping. Cinder blocks make a good edging for garden paths by laying them end to end on their sides and filling the holes with monkey grass or other ground cover. Partially buried cinder blocks placed with their smooth side up can also be used for stepping stones.

Building a Raised Flower Bed Using Cinder Blocks