Raised bed gardening
We have a problem with our soil: almost anything will grow in it. This doesn't sound like a problem, but that means in addition to the things we want to grow, like beans, tomatoes, and peppers, we are constantly fighting the weeds. I have nothing against weeding and find it quite fulfilling in its own way, but some of our weeds are nasty things that have long thorns. That takes the joy out of weeding pretty quickly. Additionally, our soil has a good bit of clay in it. Water can't penetrate easily, but when it does (like after a long day of rain), it makes a sticky mess. A plow or tiller is required, and pulling weeds becomes hard - you just can't get to the roots without a huge chunk of the surrounding ground coming with it.
At the school at which I teach, we constructed several raised beds last year, and I was really pleased with how well the school garden did. I decided to try raised beds at home. One of the appeals that gardening holds for me is that it is basically a giant experiment, one that I embrace! Like anything, the success of gardening in raised beds rests largely in the planning, so the process of planning began in February.
Based on what I had learned from our school garden, I decided to construct my raised beds out of cement block (the kind used in constructing the foundations of houses). I wanted each bed to be about 4 feet wide by 30 feet long by 2 block high (about 2 feet). Over the years, we have learned that any project becomes easier if you work within the limits of readily available materials, so the dimensions of most of our projects are built in multiples of 8 or 10 ft., which are the common lengths of lumber, metal posts, and other construction materials. The 4 foot width is wide enough to accommodate two rows of plants and allows for easy harvesting.
Some quick math showed for each bed I would need about 100 blocks. I wanted 4 beds, so that meant I needed 400 block total. Each block is pretty heavy, and when I gave the total to my husband, he looked at me with a panicked expression. Even with our trailer, this would mean multiple trips to the home improvement store. It would also mean loading those 400 block onto a cart, checking out, transferring them to the trailer, moving them off of the trailer when we got home and then placing them to create the beds. While math is not my husband's favorite, he was able to figure out that we would essentially be moving 1600 block. And then we would need bagged soil on top of that! My raised bed future was looking dim, but then I discovered that for a nominal fee of $65, the home improvement store would pull the order and deliver it right to my house. All I had to do was place my order online, and within 24 hours we received delivery of 400 block and 6 pallets of soil. (I used Miracle-gro garden soil combined with topsoil that was on special at the store).
The next step was to level the ground. We did a light till just to loosen the soil and break of the clods of clay, then roughly marked where each bed would go, allowing for enough space in between the beds so that my push mower would fit easily (about 30 inches). Then the real work began...
I'll admit, our ground looked fairly flat, so I thought putting in the block would be pretty straightforward, other than having to move 400 block that each weighed about 40 lbs. I was wrong. Ground that is kind of flat will not do. If you lay the block and they aren't perfectly level, the project won't go well. The process went something like this: 1)level out the ground as best you can for the 30 foot run on one side. 2) Place a block, cavities placing up, and see if it is level front to back and side to side. If it is (never happens!), repeat the process with the next block. 3) If it isn't level, remove the block and level out the ground as needed, place the block again and hope it is level now (if not, see step 3). A small shovel and and hand trowel worked best for me as I went through this process. Once you finish a long side, you turn the corner and work on a short side. Don't get too attached to the short side - you will likely have to move it as you square up the bed, but this lets you know where the next row will begin. Once you start of the next long row you are basically repeating steps 1, 2 and 3, but with an added twist: you have to keep the row parallel with the first row. Enter my secret weapon: the story pole. Story poles are used in construction when you need to keep a specific distance in multiple places. What I used was an old adjustable shower curtain rod. This allowed me to precisely place the block in the second long row so the bed stayed square. Once the two long rows were complete, I leveled and placed the two short rows. This will form the bottom course of the bed. Forming the bottom course took me about 2 hours for each bed. The good news is that if you do a good job on the bottom course and make it level, the top course doesn't take that long. You just stack the block, staggering this row over the first row. This takes less than 30 minutes working by yourself.
The next step is optional, but is a good safety measure: use 2 foot lengths of rebar and drive them in the cavity part of the block every 6 feet or so. This provides some stability once the soil is filled in and will also keep the blocks from tipping if you sit on them when planting or harvesting.
After the block walls are constructed, we lined the bottom of the bed with landscape fabric so that any hidden weeds wouldn't pop up later.
Once the landscape fabric was complete, the final step was to fill the beds with soil. I used 2 types of bagged soil: regular topsoil Miracle-gro garden soil. I did not use the "raised bed soil" made by several companies, mainly because at $8-9 a bag, they were budget busters. Instead I waited until my home improvement store had soil on special. I ordered half of the bags needed in topsoil and the other half in the "fancier" soil and had them delivered at the same time the block were ordered. As I filled each bed, I used a rake to mix the soils together. This was the part my husband was most skeptical of in my plan. His thinking was: "We have 30 acres of land. Why are we BUYING soil?" The answer is, putting our soil in the beds would not have solved our soil problems, it would have just raised the soil level about 2 feet. I could have amended the soil, but that wouldn't be any cheaper, and there would still be an overrun of weeds.
I filled the beds to within about 6 inches of the top, and if you just want a simple raised bed, that would be the end of the project. We chose, however, to add a few additional features to the raised beds. The first being "hoops" that would allow us to extend out growing season. This was quick and easy. We bought a spool of 1/2 inch flexible PVC pipe, cut it into 10 foot lengths and slipped the ends over the rebar that we used to anchor the block. We used 5 hoops per bed. To stabilize the hoops, we drilled small holes on either side at the top and ran wire through them, securing the wire at the ends to a post. Then we fastened fishing weights on either side of the hoop so they wouldn't blow over since our property has very windy conditions. Once the hoops are in place, you can use plastic or bird netting, depending on the season. I used bird netting since it wasn't very cool outside and my chickens were a little too anxious to scratch around in the beds. For the size hoop and bed we have, 7 foot wide netting worked well.
When the plants got bigger, we adjusted the bird netting by lifting it from the hoops and stringing it along the sides on wire we stretched between posts. This was a necessity for us in order to keep the chickens and wild rabbits from ravaging the garden.
Another add-on was securing cattle panels along the center of 2 of the beds to act as trellises for the green beans and cucumbers. Once again, the wire and posts served as anchor points and we just zip-tied to them. I've used lattice panels in the past, but we had the cattle panels handy.
The final addition we made was a water ting system. We purchased a soaker hose kit from TSC last year on clearance, and they have made watering a breeze. We use much less water, too. My husband hooked all four hoses to a single manifold so that I can control which beds are watered at any given time.
The raised beds have been even better than I hoped. Our plants are healthy, there have been very few weeds (and these are easily pulled), and the chickens have been thwarted! In our beds I am currently growing sweet potatoes, snow peas, onions, cantaloupe, watermelon, zucchini, crooked-neck squash, peppers, tomatoes, green beans, okra, turnip greens and cucumbers. I grow a lot to share, can and sell, so the average family would be fine with just one or two beds.
