Raised Bed Gardening
Raised Bed - Any ornamental or vegetable bed that has soil higher than the surrounding immediate area. Sometimes bounded by boards, stone, brick or any material to hold in the soil, raised beds make a supreme growing area.
That's how Emily Compost defines a raised bed, but the experience is something different.
Columbia, South Carolina
We wanted to place a well-defined vegetable garden in a backyard lawn that had a slight slope and whose soil was at least suspect and perhaps contaminated with construction debris left ten years ago.
It should be large enough to provide sufficient vegetables to define success, but small enough to manage with limited time and effort.
Initially we thought that four feet by six feet would provide both challenge and vegetables.
We initially thought we should build the border with wood. Wood is easy to use, completely adaptable as to size, and not unpleasant to look at. However, wood rots. Dirt and moisture pretty much define a garden and also pretty much declare the demise of wood. So we needed treated wood or a wood that is impervious to rot.
Treated wood did not seem to be in the spirit of eco-friendly growing. Do treatments leach into the soil? What are the issues involved?
Cedar would not need to be treated but was expensive and had environmental issues of its own.
It would be easy to buy some 2x6 lumber, screw them together and try them out for a season or two. Very little risk. There are also quite a number of pre-packaged raised bed kits on the market, but, again at a greater cost.
I don't know where the inspiration for stone came from, but we looked at decorative stones, bricks, and finally settled on cinder blocks mainly for cost considerations.
Measuring out the garden and dividing by the length of the cinder blocks we did our math and bought twenty.
Halfway through loading them into the car, we thought, "Maybe wood would be lighter."
In a four by six bed (24 square feet), six inches of soil meant we needed 12 cubic feet of soil. So we bought that much of the least expensive soil that we could find. Add to that one bag of cow manure and one bag of chicken manure. We could have studied this to death and made some intelligent calculations of nutrient value of more expensive soil or details of more defined manure, but we figured, "let's get on with it."
One advantage of a raised bed and especially of raised cinder blocks is that if you don't like it, you can make it completely go away next year. But for now, we wanted to give it a shot. Let's figure out where to place the garden.
We had already scoped out the daily sunlight in the yard and made some calculated guesses where the sun would be in a few months.
We laid out the bricks and thought about it overnight. The next morning we removed the grass beneath so we could level the bricks in the lawn.
Next we dug out the lawn inside the garden, shook out the dirt, and discarded the grass. (There are those who suggest just dumping the new soil on top of the existing lawn and letting the grass decompose beneath your garden. However we wanted the roots to go deeper into the ground and so we decided it would be best to remove as much of the grass as we could.)
After removing the grass we turned over the yard another six inches, removed debris that we found, and added the soil and manure. We also filled in the holes of the cinder blocks with soil, intending overflowing plants to soften the look of the blocks in the lawn.
With little more bother, we defined some rows and planted the seeds.
After a few weeks.
After 30 Days!!
After six weeks.
After seven weeks.
Meanwhile in another part of the country, we used a raised bed made of treated lumber that came with the house when it was purchased. It was impossible to tell what the original purpose of this bed was (it could have been a doggy potty box or a children's sand box: the evidence was lacking) but we moved it into a sunny place and filled it with compost and dirt from the main garden.
Planted with lettuce and arugula it has grown with almost no weeds, especially when compared to the main garden right next to it.