I’ve been nudging my wife for some years now about putting in a garden. There are a few reasons I think a garden is prudent:
- Food is expensive. Food we grow is food we don’t need to buy.
- Possibly the time is coming when being a little self sufficient will be very important. Better to have the infrastructure in place now.
She has previously fended off my suggestions with recriminations about my helpfulness, or lack thereof, the last time we tried to grow something1. During one lively engagement on that topic, we stumbled across a point on which we agree: bending over, or kneeling, to work in a garden, sucks. From that, we came to an agreement that we would try a raised bed garden.
The space we decided on runs along the south end of the garage. It’s about 36’ long, and 7’ wide. In high summer, the whole length gets good sun. It’s also in easy reach of a garden hose. We decided to put in three beds, 9’ long by 3’ wide, right up against the garage wall. Because we are both tall, we set the bed wall height at 32”. We could have made them taller, but we knew we’d have to reach over the width of the bed.
The beds are an up-front capital investment. There are plenty of examples online of people building raised beds out of untreated framing lumber and plywood, but I wanted these to last a while. I decided on a design of treated lumber and steel barn siding. Happily, I started this in March, when materials were inexpensive2. One point was to make sure the treated lumber was rated for contact with the ground. Not all treated lumber is created equally, and the cheaper stuff (*cough* Lowes *cough*) is only rated for exposure to weather, not constant contact with soil.
The beds are just a box sitting on the ground. The box doesn’t need a bottom, just walls. Each wall is a wooden frame with the steel siding on the inside face. Just whack together the frames and done, right? Well, kind of.
Nailing or screwing into the end grain of wood is a weak joint for construction that will be exposed to weather. As time passes, the wood fibers shrink. A fastener driven into the end grain is parallel to the wood fibers. As those shrink, they pull away from the fastener, weakening its the grip.
I put my frames together using pocket screws. Or rather, regular screws in pocket screw holes. The “pocket” hole is drilled with a special stepped bit, at a shallow angle to the side of the board. When a screw is inserted into the pocket, the threads protrude out through the end grain, so that they can be driven into the side grain of a perpendicular board. This is a better joint.
The frames are screwed to each other through the vertical members, so I was screwing through side grain into side grain.
I had read about concerns that the chemicals in the treated lumber would leach into the soil. I can’t say that those concerns are unfounded, so I took precautions. The whole inside of each bed is covered in the steel siding. The screws that hold the siding on have rubber washers, so the screw holes are sealed up. To the extent possible, the treated lumber will not come in contact with the garden soil.
The steel siding is oriented vertically. The siding is most rigid along the corrugations, so installing it vertically means the strong axis only spans 32”, instead of 9’ if it was oriented horizontally. The siding comes in 3’ x 12’ sheets, so I had to cut it into 32” lengths3. The jagged edges will cut a bitch, so I covered them with some J-channel.
Since the beds are 9’ long, I was also concerned about the sides bowing out under the weight of the dirt and water inside the box. At 3’ in from each end, top and bottom, I ran a piece of ¼” all-thread from side to side, with nuts on the outside, as reinforcement. To prevent the all-thread rusting (particularly the pieces that will be buried at the bottom of the bed) I enclosed the all-thread in ½” PVC conduit.
Before putting the boxes in place, I leveled out the spots where the beds would go. Really, just the parts where the bed walls would actually sit. Any high spots in the middle were just going to get covered with dirt.
One of the things I came across browsing for videos on raised beds, was the idea of Hugelkultur4. The basic idea is that you put layers of compostable mass at the bottom of the raised beds, and this releases nutrients into the soil over time. I don’t know how realistic that is, but I do know that I had a bunch of twigs and branches that I could dispose of by burying them in the beds. We were also just tossing compostable kitchen waste into the beds for the week or so before the dirt showed up. We filled the beds maybe 1/3 full with compostable material.
Based on some random internet website5, I calculated we would need six tons of topsoil to fill the beds. At the last minute, I panicked and reduced the order to five tons. That was a good call, as it turns out. We had the dirt dumped onto a big tarp at one end of the line of beds. We also picked up a ton of sand, and some unknown quantity of chicken manure from my in-law’s farm. We planned to cut the sand (for better drainage), chicken manure and our own kitchen compost into the dirt as we filled the beds. It took a weekend to fill the beds, shoveling dirt into the wheelbarrow, cutting in the sand and manure, dumping the wheelbarrow in the beds. We had probably two tons of dirt left.
We ran out to the wife’s preferred nursery and bought a bunch of stuff: cucumbers, tomatoes (cherry and normal), sweet peppers (mini and normal), green beans, melons, cabbage, broccoli, and cauliflower. Peas and carrots we planted from seed. Our compost pile generates volunteer butternut squash every year, so we transplanted some of those. If that sounds like a lot, it was. We cheated the minimum spacing for everything. Since there was space between the beds, we put the vining plants (squash, pumpkin, melon, cucumber) at the ends so they could grow over. We got some wire frames6 to support the tomatoes and vines.
Results and Lessons
Most of the plants grew well. The carrots did not (crowded out by broccoli) and the peas did not (started too late, too hot). The butternut squash grew like crazy, giant leaves, plenty of blooms, but not one single squash. The father-in-law told us this is a soil composition problem, that happens with too much nitrogen (chicken manure). We got plenty of cucumbers, and some decent heads from the broccoli and cauliflower. We got some green beans. The full size peppers have not produced well, but the mini peppers are making up for it. The tomatoes went completely ape shit. The melon and pumpkin both have three or four good size fruits working.
The big lesson is, we overestimated what we could do with the space available. When I was building the beds, I was focusing on the volume of the beds. I was thinking, these are huge. However, what matters is surface area. The minimum spacing requirements really do matter. We planted too much. Our tomatoes are so close together, and so big, the fruits in the middle are aren’t getting sun to ripen. The beds being up against the garage is also sub-optimal, particularly with the tomatoes. The vining plants are all over between and in front of the beds, making access a little difficult.
Next year, we’re planning on putting in at least one more bed. This one will be away from the garage, so we can get to both sides. We’ll probably put the tomatoes in this bed, to address the issues we had this year. Also, we’ll crack out the Organic Method book and get some advice about soil composition for specific plants. Last, we’ll look at putting in plants at the best time for each type. This year, we waited on everything until Last Frost Date for Ohio (sometime in late May). Next year, we’ll look at putting in some types earlier (peas). The wood frames of the beds will make it easy to attach an improvised greenhouse-ish cover if we’re worried about hard frosts.
1 Strawberries. In my defense, we planted about 160 ft2 of June-bearers, based on some dubious advice.
2 Jesus wept. My ass still hurts from the cost of the materials.
5 DDG “how much topsoil in a ton”, input some BS numbers, get a BS result.
6 https://ohioamishcountry.info/directory/berlin-seeds/. Silly Amish don’t have a website of their own.