The No Excuses Raised Bed Garden
By John Dunbar
Summer 2001

 

Dr. Randall of Urban Harvest has recommended the use of cement blocks for our urban vegetable gardens.  His book, Year Round Vegetables, Fruits and Flowers for Metro Houston, points out that cement blocks have the greatest overall convenience and material safety for backyard gardens, and they are not very expensive.  Following his advice, I have put in five gardens using various sizes of cement blocks.  This article describes small cement block gardens that can be easily built by anyone.

 

Types of blocks

These are the popular types of cement blocks for gardens in our Gulf Coast area found at most hardware stores:

-  8" x 8" x 8" solids,

-  8" x 8" x 16" construction (hollow),

-  4" x 8" x 16" solids,

-  4" x 16" x 16" solids.

 

Of these, we need to exclude the 4"x16"x16" as being too heavy and unwieldy for most people.  The 8" x 8" x 8" solids are popular at many community gardens as they are easy to sit on, and they are fairly easy to lift.  These blocks work out for the larger gardens because they are sturdy.  But I find them difficult to keep in alignment and they don't provide the soil depth that I prefer.

 

I use the 8" x  8" x 16" construction (hollow) blocks and top them with a 4" x 8" x 16" solid block laying sideways.  That gives me the height and the sturdiness required for an urban garden bed.  I can walk on top of these 12 " high walls.  The increased depth gives plant roots more room to grow.  The drawback is these take more alignment when building. But these are the only combination of cement blocks that hold their alignment past one growing season.

 

For one of my wife's small gardens, I used a smaller and easier to build format.  I now think anyone can build one of these smaller gardens in a very short afternoon.  It has the same height as the 8" x 8" x 8" solids and it is much more convenient to put in.  The only problem is that you just can't sit on the garden's side walls as this garden is built with the 4" x 8" x 16" blocks.  Because it is built with the narrower block, the walls are not appropriate for wide gardens.

 

I call it the "no brainer / no excuse raised bed garden" because its narrower blocks are easier to handle.  I recommend this style to all my friends who are just getting started in vegetable gardening and want something to grow smaller plants, or want a garden that can squeeze into a small space.

 

How to Build

 

It is best to lay out your garden with stakes and strings before you start.  However, here's the good news: you can often forego this step when using these smaller 4" x 8" x 16" blocks.  You can simply layout these blocks along the paths you desire and any necessary corrections can be made on the fly.  My wife and I made these gardens narrow because the 4" width allows us to squeeze the garden into tight places.

Typically, the garden might be only 2 feet wide by many feet long.  I believe you could make the bed wider but it really fits a small width best.  The overall garden should not slope too much as the rains will wash the soils to one end.

 

After I have the blocks tightly laid out in their positions.  I take a spade and dig or scrape out the soil underneath those blocks that are too high. Then after it looks relatively level I check that the crevices between each of the blocks are in alignment. When I'm satisfied with this alignment, I lay down six to eight sheets (more is better) of newspaper along the bottoms of the bed to keep the weeds from sprouting.  Then I add my garden mix soil. I usually buy the garden mix soil from Gardenville in Stafford.  The soil can be ordered in large plastic bags that are fairly easy to carry using a dolly.

 

Please note there is a big difference between "Garden Mix Soil" and "Top Soil". Generally the garden mixes have lots of organic material added in the form of compost.  Also, Gardenville sells compost separately and we often use this as well.

 

What To Plant

 

This type of garden is appropriate for any smaller type of plant. We plant all kinds of lettuce.  Currently we are harvesting Red Sail's Lettuce as well as Chinese Lettuce ("Wah Gee").  We also have lots of Edible Chrysanthemums ("Shungiku"), Garlic Chives and Green Onions. There are two small Red Cluster Pepper plants growing there also. Next year we will try out some Mizuna in this garden.  Last year we grew Fennel.

 

Benefits

 

Because the cement blocks are only 4 inches wide I can put this garden in tight corners, or follow fence lines with it.  I can build one of these gardens easily in an afternoon including the planting of several feet of onions.  The gardens do not cost a lot to put in.  They are easy to set up.

 

Maintenance

 

Maybe once a year you will need to check the alignment of the blocks. If they prove troublesome, then you can drive in some short (12" or 18") steel rebar rods along the sides.  These can be bought at Loews Hardware.  Also, you will need to periodically add more garden soil as time passes.

 

Is it easy?

 

It's extremely easy.  First, drive over to Home Depot to buy the blocks. They will load up your car for you.  The hard part is taking the blocks to the proposed location for your garden.  For this you will need a very inexpensive two-wheeled dolly.  Buy the one with the fattest tires - they won't sink into the soft ground.  Scratching or digging the dirt under the blocks for alignment can be a little difficult when you try to go through some tough sod.

 

When you are ready to load your garden with garden mix soil, you can buy the soil in bags and carry it with the two-wheeled dolly also.  At Gardenville in Stafford, if the bags are too heavy you can ask them to repackage them into two halves.  I've done this when buying bags of sand.  They didn't charge extra for this.

This garden is easier to build than using the 8" x 8" x 8" blocks and can fit into tighter spots.  They are much easier to build than our larger gardens which require two layers of blocks.  This garden is most appropriate for small spaces... and is just the type for beginners.