Sunday, July 4, 2010

Raised Bed Gardening

A quick search of "raised bed gardening" will bring up a basic list of its fundamental advantages... Loose soil, warms sooner, less maintenance, better drainage. Those are all fine and dandy. Perhaps you have other reasons. Significantly raised beds are easier to work. Just imagine being able to sit down and work the beds instead of bending and reaching, hurting your back?


Regardless of your reasoning, building the beds are simple. My own photos will be coming online as soon as my project is done. My personal garden this year (as I've just moved and am starting over) will consist of twelve beds measuring four feet by eight feet. I am also using some reclaimed lumber from my parents' deck. Since I'm on a budget anyway, the beds will initially be just 5-6 inches tall as the boards from the deck are only roughly 5.5 inches wide. To summarize so far...

  • Beds will be 4' Wide x 8' Long x 6" Tall
  • Beds will be held in places with four corner stakes made from 1" x 1" lumber
  • Lumber used is reclaimed decking (previously pressure treated but at 15 years old, I'm not too worried)
  • The sides are 1" x roughly 6"
To fill in the beds, I have extra top soil on hand. Many suggest cutting and removing sod but instead, I would turn it over. This will kill the grass and add more organic material to your beds over time. This is also handy if you're just starting out and don't have any compost yet. If you don't have any topsoil on hand, it can be bought by the bag (and you will need many many bags just for a few beds) or you can obtain good topsoil from many nurseries or hauling companies. It should at least be dark and rich looking, loose, and contain few if any rocks. You will need to fertilize or add compost/manure to this over time anyway so while starting with good soil is important, it isn't impossible to improve it. This all depends on your budget and needs.

For more detailed instructions, try Lowe's Creative Ideas website. They also have a video how to.

My Project
One of the main reasons I need to build raised beds is the massive water problem in my yard. The area is heavy thick clay and retains water badly. My plants would drown. See the photos of the standing water (1 and 2) and my foot in the middle of it (1). The raised beds are getting the plants out of the water.
Materials and Specs
  • Lumber
    Do not use pressure treated wood for vegetable gardens. Nix railroad ties too. Unfortunately the chemicals found within them will leach into the soil tainting your food. Try cedar or redwood for rot resistant lumber.
  • Blocks or bricks
    Cement cinder blocks and bricks can also make fine beds. This is a more permanent solution though. I have also read about chemical issues on cement but honestly, I doubt it. Its a rarely raised issue.
  • SizingFigure out what you can comfortably reach, either sitting or knealing, then determine your bed size. I made my beds four feet wide so I can comfortably reach everything inside without walking on it. Some people make beds five feet wide and yet others only go two or three feet. Length is only limited to what is convenient for you.
  • SoilSggestions here can vary. I prefer to go with a no dig method. This means that once the soil is in place, it is only minimally disturbed. This saves the soil structure (quick version: over time bacteria begin to grow in the soil and this is beneficial to plants, digging the soil disturbs the bacteria). No dig has been found to improve harvest yields no only in home vegetable gardens but also in large scale agriculture. The other route that some suggest is deep digging. This is digging up the initial twelve to sixteen inches of soil before adding anything to your frame. If you really wish to do this, I suggest waiting a season. Growing in the grow for a season will actually loosen the original soil and make it easier to work.
The Down Side (well maybe...)

Moisture

If you're in a poorly drained area, raised beds make sense. If you live in a fairly dry area, the beds can actually dry out faster. This is not always the case as raised beds often lead to closer planting which encourages better moisture retention.

Instead of building raised beds, you can invert them in dry areas.  By double digging and removing the soil, then replacing only half, you create a depression where water will naturally go.