Give Your Garden Beds a Finished Look with Corner Blocks

Setting up garden beds is a great way to make room for plants like herbs, vegetables, flowers, and more. The blocks that line the sides of garden beds keep the soil in place, stop it from washing away, and give the bed a nice, finished look. What about the corners? If you leave them open, the bed might look like it’s not finished. Corner blocks are a simple way to make your garden beds look neat and professional, whether you made them yourself or bought them.

What Are Garden Bed Corner Blocks?

Garden bed corner blocks, also called planter corner blocks or raised bed corner blocks, are blocks specially designed to fill in the corners of garden beds. Most corner blocks are the same height and length as standard garden bed blocks Corner blocks interlock or stack securely onto the ends of the straight blocks used for the sides of the bed. This locks the corners into place and prevents gaps or weak points

Corner blocks are typically L-shaped, with two sides that are the same length as the sides of the bed. However, 45-degree angled corner blocks are also available. These produce a rounded corner that has a more natural look. Corner blocks come in a variety of materials including concrete, plastic, stone, and wood.

Benefits of Using Corner Blocks for Garden Beds

There are several advantages to using corner blocks for raised garden beds and planter boxes

  • Gives beds a finished, uniform look. Corner blocks finish off the look of the garden bed in a neat way.

  • Prevents erosion and soil loss. Corner blocks keep the dirt inside and stop it from washing out around corners that aren’t blocked.

  • Allows efficient use of space. Corner blocks maximize planting space and avoid wasted space in bed corners.

  • Keeps plants and soil contained. Corner blocks provide a border that keeps garden soil and plants neatly in the bed.

  • Adds decorative interest. Corner blocks come in various colors and styles that can complement the look of the garden bed.

  • Provides a firm edge. Corner blocks give the edges and corners of beds more stability and reinforcement.

  • Easy installation. Corner blocks simply stack or lock into place without requiring special skills.

Choosing Corner Blocks for Your Garden Bed

If you’re looking to add corner blocks to your new or existing raised garden bed, there are a few things to consider:

  • Material: Corner blocks come in concrete, plastic, natural stone, faux stone, wood, and more. Consider appearance, durability, and cost.

  • Size: Measure your bed to determine the required length of the corner blocks. Standard sizes are 6″, 8″, and 12″.

  • Style: Choose from basic 90-degree corners or angled 45-degree corners based on the look you prefer.

  • Color: Select a neutral color that matches or complements your garden bed blocks.

  • Weight: Concrete corner blocks are durable but very heavy. Plastic or wood may be better options for large beds.

  • Budget: Concrete and stone corner blocks tend to be more expensive than plastic or wood. Choose the best material for your needs and budget.

DIY Concrete Corner Blocks

If you want to save money on corner blocks, you can make your own concrete blocks for garden bed corners. Here’s a simple DIY concrete corner block method:

Supplies Needed:

  • Concrete mix
  • Mold for corner block (an upside-down storage bin works well)
  • Shovel and trowel
  • Water
  • Mixing tub


  1. Prepare the mold. Coat the inside with cooking oil or plastic sheeting so the concrete won’t stick.

  2. Mix the concrete according to the package directions. The mixture should be dry and firm.

  3. Scoop concrete into the mold, packing it down firmly. Smooth off the top.

  4. Allow the concrete to cure for 1-2 days before removing from the mold.

  5. Use a chisel or putty knife to smooth any rough edges. Allow to finish curing for a full 7 days.

  6. Seal the concrete blocks with an exterior sealer to protect from weathering.

  7. Install the corner blocks at the corners of your garden beds using standard masonry techniques.

With some simple materials and a DIY spirit, you can create durable, customized corner blocks tailored for your garden!

Shop Corner Blocks for Garden Beds

Rather buy your corner blocks than make them? Many home improvement stores carry corner blocks made specifically for garden beds and planter boxes.

Some top options include:

  • Oldcastle Tan Brown Concrete Planter Wall Block: Interlocks with standard wall blocks and features a natural stone-like look. Approx. $5 per 7.5″ x 7.5″ corner block.

  • Pavestone Rumbled Stone Large Corner Block: Made of natural stone in a tumbled style. Approx. $13 per 8″ x 8″ corner.

  • New England Arbors Garden Bed Corner Block: Plastic corner with faux wood grain; lightweight and easy to handle. Approx. $9 per 7.5″ x 7.5″ corner.

  • Keystone Freestanding Garden Bed Corner Block: Textured, multi-colored concrete suited for freestanding raised beds. Approx. $6 per 8″ x 7.75″ corner.

  • Veranda Bed Corner Block: Rustic faux stone suited for use with Veranda bed kits. Approx. $13 per 12″ x 12″ corner.

Check product details to ensure the corner blocks match up with dimensions of your existing garden bed or planter box blocks. Prices will also vary by retailer.

Installing Corner Blocks on Your Garden Bed

Adding corner blocks to your raised garden bed or planter box is a simple weekend project. Just follow these basic steps:

  1. Clear any debris from the corners and level the bed area if needed.

  2. Dry stack the corner blocks without mortar. Level and align with bed edges.

  3. Use gravel, sand, or soil to backfill any small gaps between blocks if needed.

  4. Ensure the blocks are stable, level, and properly support one another.

  5. Consider using exterior construction adhesive between blocks for added stability if needed.

  6. Fill bed with soil mix up to 1-2 inches below top of blocks.

  7. Plant flowers, herbs, vegetables or other plants as desired.

  8. Periodically check corners and adjust blocks as needed over time.

And that’s it! Adding corner blocks is an easy way to put a polished finish on your DIY or store-bought raised garden beds. The finished corners give your bed a neat, planned look that makes your flowers and plants pop.

Get Creative with Corner Block Designs

Standard square corner blocks certainly get the job done, but don’t be afraid to get creative! Here are some unique ways to use corner blocks:

  • Contrasting colors: Use corner blocks in a different color from the straight blocks for visual interest.

  • Alternating materials: Combine different materials like concrete and wood at the corners for texture.

  • Plant pockets: Choose corner blocks with recessed pockets to plant flowers or herbs.

  • Edge seating: Use extra-wide corner blocks to create a place to perch or rest.

  • Accent lighting: Set lighting fixtures into corner blocks to illuminate the garden bed at night.

  • Water features: Use watertight corner blocks with tubing to create a small cascading waterfall.

  • Corner trellises: Include tall, angled trellises built into the corner blocks for climbing vines.

Think outside the box and discover unique ways to make functional and beautiful garden bed corner blocks!

Maintaining Garden Bed Corner Blocks

Corner blocks are designed to be long lasting, but periodic maintenance will keep them looking their best:

  • Remove any weeds or grass growing in corner block cracks.

  • Re-level any shifted or settled blocks to keep the bed square.

  • Fill gaps between blocks as needed with added gravel or soil.

  • Replace any severely damaged, cracked, or crumbling blocks.

  • Reapply exterior sealer on concrete, wood, or other porous blocks every 2-3 years.

  • Pressure wash stained blocks with mild soap and water when needed.

With proper installation and occasional maintenance, quality corner blocks should last for many years of gardening enjoyment!

Give Your Garden a Finished Look

Adding corner blocks is a straightforward DIY project that can instantly take your garden beds to the next level. Corner blocks contain the soil, prevent erosion, maximize planting space, and provide a clean, finished look to your garden bed or planter box. Choose corner blocks that match the height, length, and style of your existing blocks. Or get creative with unique shapes, materials, or built-in features. Your plants will thrive within the tidy, well-defined borders, giving your garden space a polished, professional look.



Are concrete blocks safe for raised garden beds?

Build your raised bed with a decay-resistant type of wood, such as cedar, black cherry, oak (bur, chestnut, post, white), black locust, Osage orange, or redwood. (Source: USDA Forest Products Lab) Use a non-wood material such as stones, concrete blocks, bricks, or synthetic lumber.

How many cinder blocks for a 4×8 garden bed?

20 blocks will give an interior bed area of 4′ x 8′. Leave a side open to bring in the soil until the new bed is filled. No mortar or special installation is necessary unless you desire a bed which is higher than 8″ raised over the surrounding area.

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