First let me apologize for a lack of pictures while the project was in the process. I always think I will take some then get engrossed in the project and totally forget. Anyway, my wife and I really wanted a garden at our new home but we have a group of deer that live in our yard. So instead of just creating a regular garden I decided to have a 2 tiered garden with a raised bed around the outside and a regular garden enclosed in the middle. We currently have zucchini, watermelon, and some tomatoes growing in the lower level. On the top level we have tomatoes, carrots, 2 kinds of peppers, beans, basil, cilantro, onions and peas.
Step 1: Prepare Your Garden Area and Plot Out the Location of the Exterior
We already had a garden in our yard although the prior owner let it go. So I spent a lot of time cleaning out grass and weeds from the area. Once I had the weeds cleared out I outlined where each of the support posts should be located. The exterior measurements of our garden are about 18 x 8 I chose these dimensions to try and limit the number of cuts I had to make on the sides of the raised bed.
Step 2: Add Support Posts
I used treated lumber on all parts of this project since it would be outside and we would be watering the garden or a regular basis. The posts are 4x4 and about 4 feet tall, I bought 8 footers and cut them in half. Each post is sunk 10 inches into the ground giving the garden a height of 38 inches. I didn't bother with concrete footings because the weight of the wood and dirt is plenty to hold everything in place, not to mention there are 10 posts in the ground. The reason the height is 38 inches is because the boards of the support walls are 2x8. Which actually means 1.75x7.5 so when I put 5 on top of each other they came out to about 38 inches high. I simply attached the support posts so the walls of the raised garden are flush with the tops of the posts. I used reverse engineering a lot mainly because I seem to be terrible at measuring. (not sure why since I have always been good at math) Anyway, when I was buying wood I wanted to minimize the number of pieces and cuts and the easiest way was to make the number match the wood rather than cut wood to match my arbitrary numbers.
Step 3: Connect the Walls
As you saw in the last step my one post is a little crooked and that is because of the technique I used to assemble the walls. I attached the two very exterior posts to the boards that would make up the left and right sides and stood them up making them as level as possible. I then worked my way around the outside of the garden sinking a post and attaching the boards as level as possible then finished the insde. When I got to the last post it had to be crooked to get everything connected. It's not as bad as it looks in the picture. I decided to use bolts because I had some left over from another project and liked the way they look. I counter sunk the nut so that it would be covered as much as possible from the elements. I used one bolt on each board which seems to be holding fine, I probably could have used 2 just in case but after testing with my weight I was happy with one. My total for all posts and wood is 3 support posts in the back, 3 on the inside, and 4 in the very front. So 5 8 ft 4x4 cut in half.
The wood sides are all 2x8, the back has 5 boards 12 foot each and 5 boards 6 foot each. The sides each have 5 boards 8 foot each, so 10 total. The two front ends each have 5 boards 2 foot each so 10 total. The interior parts do not go all the way to the ground so I only had to use 2 on each side to contain the dirt. The sides are each 6 feet long (4 total) and the ones along the back/interior are 8 and 6 feet long (2 of each). This made the raised bed about 15 inches deep and 2 feet wide at any one spot. I wasn't sure if this was enough although as you can tell things are growing just fine.
Step 4: Bottom Support
I had to work a little at figuring out how to attach the bottom of the raised garden. What I decided to do was attach a support rail along both sides of the garden then simply lay the boards across the support rails. I had a fair amount of the 2x8 boards left and simply cut them to 2 feet long, laid them on the rails and screwed them into the rails to keep them in place. Since this was holding the majority of the weight of the dirt I decided the more screws the better. I had some general purpose screws from another project and they worked fine.
Step 5: Line With Landscaping Fabric
To keep the dirt in the bed and still allow water to drain out effectively I lined the entire bed with landscaping fabric. It still holds water in pretty good but allows it to drain out the bottom as necessary. My wife was also concerned about the wood having chemicals and so that made her happy to have a layer between the dirt and wood. Plus I had it laying around the garage. I used a staple gun to hold it in place
Step 6: Add the Rabbit Fence
I wanted the fence around the top to keep out deer and the one around the bottom to keep out rabbits. On the back I simply attached some garden stakes and then attached the fence to them. In the front I hid the stakes inside the bed and attached the fence again. On the bottom level I drove the stakes into the ground and then attached the stakes with staples to one side. I didn't attach them to the other side in case I want to bring in a rototiller each year. I also have a small row of bricks in the front to keep the fence down, plus they were also just laying around the garage.
Step 7: Add Dirt and Plant Plants
I was able to get free dirt from the dump and then added some fertilizer and peat moss to help things grow. We started all of our plants in a seedling thing my wife had and then transferred them to the garden later on. I rented a rototiller for the bottom garden since the dirt was pretty crushed down with all the work I did making the garden.
Thanks for reading look forward to any questions!