Backyard Garden Grower
Plan, grow, work, watch, and eat
Here's a design and instructions for a beautiful raised bed garden. The design here will call for a 6'x4' raised bed that is approximately 8'' off the ground.
Step 1 - Buy two 10' x 10'' x 2'' wood planks. These can be found at any local lumber department. Get the planks cut also at the 4' mark. Most places will cut it for you if you buy it there.
Step 2 - Use 3 screws on each end to assemble the box. The ends should alternate so that you have a more square box than rectangular (see the right picture vs the left below). Since the square foot gardening method is recommended, a square box will make this method easier to follow. Here's why. If you don't alternate the ends you will end up with a box that is 6' in one direction, and 3' 8'' in another. You lose 4 whole inches in one direction. This can really mess up your square foot gardening because you will have to either have one 8'' square, or 4 10.25'' squares. What can happen if you alternate the corners however is you end with a box that is 5'10'' by 3'10''. This means that you can now have 24 squares that are 11.25'' by 11.75'' (approximately 11.75). This will give squares much closer to 1' x 1'. Of course, to avoid all this confusion just use 4 planks of wood that are all 2'' longer, and then all squares will be exactly 1' x 1'.
Step 3 - The next part is putting your raised bed in your desired location. Some people will plop it down and be done with it. You can do that. However digging a 2''-3'' trench where you will be placing your bed can be advantageous. This is for two main reasons. The first is you now have 3'' less of soil to worry about buying to fill the bed up. The second is for looks. Placing your bed onto the ground withouth trenching will cause the bottom of your bed to be off the ground in some places, and some do not like that look. Placing it in the ground a bit allows for a nice uniform look of the bed coming out of the ground, and the bottom of the planks being hid from view.
Step 4 - You'll need to add soil to your bed. Knowing how much soil to add however can be a tough task. Let's use some math to figure it out. If you alternated the ends of the wood planks you will have a 70'' x 46'' box. This multiplied together gives you an area of 3220 inches squared. Now, you need to now multiply this by your box depth to get the volume. You originally had 10'' high wood planks, but 3'' are taken up by the trench you made. Also you probably don't want the soil all the way up to the top, so let's cut an inch off the top. That gives you 6'' of depth you need to work with. So we can multiply 3220'' squared x 6'' to get 19320 inches cubed. We can convert this number to cubit feet by dividing by 1728 (this is from 12*12*12, or the fact that 1 cubic foot is 1728 cubic inches). We end up with 11.2 ft cubed of volume to fill. This means you can now go to any store that sells soil and compost and know exactly how much soil to get. They usually sell bags in 1, 1.5, 2, or 3 cubic feet, just be sure to check the bag size on the front.