Well-drained soil makes gardening so much easier. And some folks are fortunate enough to have this with no real effort required, once their plot has been prepared. But gardeners who have a base soil that drains poorly may want to consider using raised beds instead of the traditional type of garden plot.
With lots of time and effort, not to mention the outlay of some cash, you can turn your heavy earth into rich humus filled soil. But why go through all that when you don’t have to? It’s simply a lot quicker and much easier to build some raised beds to use for your garden patch.
A raised bed is simply soil that is mounded higher than ground level and formed into a flat surface suitable for planting. There are two basic types of raised beds: freestanding and contained.
As the name suggests a freestanding raised bed has nothing enclosing it. The top is flat or may be slightly rounded, with sides that slope. With a freestanding bed, you can easily change the size and shape of the bed, or even move it to a new location.
One disadvantage of a freestanding bed though is that with nothing holding the soil in, over time some of the soil will almost certainly wash away from the bed, due to rainfall or even just watering.
That’s why a contained raised bed is more commonly used. This type will have a semi-permanent frame built around the perimeter. You can use a wide variety of materials for the frame. Everything from bricks, concrete blocks, or rocks, to landscaping timbers, or railroad ties works well.
(I would not use railroad ties for a vegetable garden, as you would not want the chemicals used to treat them to leach into vegetables that you are going to eat.)
You can even utilize pressure treated boards for the frame. To hold them in place, drive stakes into the ground and attach the boards to these stakes. You can also use rebar.
If your garden plot is located near your house, you may want to choose a material for the framework which will blend into the surrounding area. It probably won’t matter as much if your garden is tucked away in the backyard.
I used cinder blocks for my raised bed garden, and spray-painted them meadow green to match the grass.
There are lots of advantages to having framed beds. For instance, with a freestanding bed, you’ll constantly be fighting to keep grass and weeds from creeping into the bed area. By using a frame, you provide a barrier to grass and weeds which will save you a lot of aggravation and time.
When building a raised bed garden in a new area, it’s best to mark off each area that you are going to use, and remove grass and weeds before constructing the bed. You may also want to till the area in order to loosen the soil and so promote better drainage. Be sure to remove any weed roots or grass rhizomes after tilling.
I removed all of the grass for my first raised bed garden, and let me tell you it is a lot of work. I don’t deny that it is a good way to go, I’m just saying it is hard work if you’re building a large garden. (I was making four beds, 4 feet X 24 feet.)
Anyway, what some experienced gardeners told me to do make sense to me and I tried it… And it works just fine.
What I did was I framed out my raised bed garden with cinder blocks right on top of the grass. Then, I covered all of the grass inside the raised be with flattened out cardboard boxes that I got from grocery stores. Then I just filled in the bed with my soil mix.
The cardboard makes a temporary barrier against the grass and weeds and will kill it before it bio-degrades into a mulch that worms love (you definitely want worms in your garden!)
With the grass and weeds subdued, they will not grow any more being buried under your soil (your bed should be at least 8 inches deep, or more) because they need sunlight to grow.
Another benefit of building your raised bed garden on top of the existing grass is that it preserves the eco-system that is already in place beneath your grass. Removing the grass and tilling destroys that existing eco-system, and you have to create a new one from scratch.
Once you’ve prepared the area, it’s time to add soil. Add the highest quality soil that you can to the bed area, and continue to add humus-rich earth, on a regular basis to maintain a high quality environment for your plants. After you’ve prepared your beds, you may want to test the soil periodically to ensure that it is properly balanced in order to get the highest possible yield.
The higher you can build the raised beds, the better, especially if the soil under the beds is of poor quality. That’s because even with a raised bed, if your area sustains heavy rainfall, drainage of excess moisture will take awhile to penetrate the heavy soil that is underneath the beds. But at a minimum you should plan on adding at least 8 to 12 inches of soil to the bed area.
The more soil you have above the ground, the more quickly the beds will dry. And in spring, the soil will warm up more quickly than soil in the ground, allowing for earlier planting.
One other advantage is that raised beds are a more accessible way of gardening for the older gardener. Instead of kneeling down or stooping over to ground level to plant or pull weeds, with a raised bed the garden is closer to the gardener. It’s even possible to sit on the edge of the bed or on a small stool and have the garden within easy reach to work.
With proper planning, a raised bed garden can even be made wheelchair accessible. Just allow adequate space and have relatively flat and smooth paths between each bed.
It’s virtually impossible to avoid treading on the ground in a traditional garden. But with a properly planned raised bed garden, there is little chance of the soil becoming compacted from being walked on. And because the soil is loose, it allows for better root growth too.
For the most efficient use of space as well as ease of working your raised garden beds, plan on building them so that you can easily reach the middle of the bed from either side, without having to ever set foot in the planting area itself.
How far that is will depend on how far you can comfortably reach. But generally a width of 4 feet seems to work in most cases. And of course, you can build each bed as long as you’d like to make the best use of your available space.
With raised beds, less water is needed because you don’t have to soak the entire plot. Only the beds need to be watered. The same applies to fertilizers, if you use them.
Because you are planting in a confined area, you don’t have to leave walking room between each row as you would in a conventional garden plot. Although it’s important to leave some space between each plant, without rows there is going to be less open ground, which means less opportunity for weeds to germinate.
And with plants being closer together, they act like mulch, helping to conserve moisture in the soil. This is important because although raised beds encourage better drainage, they do tend to dry out more quickly because they are above ground level.
Even so, you may have to water more frequently than you would in a conventional garden. But more frequent watering is really a small price to pay for the convenience of gardening with beds that are raised.
As you can see, there is a lot to like about raised bed gardening. Once you get the initial constructing of the beds done, you can look forward to years of spending more time on the planting and harvesting, and less time on the weeding and upkeep.