A few years ago, I enlisted some friends to design and build two raised garden beds* for a local nursing home. The goal was to design a raised bed that would be easily accessible for elderly people who were working while standing or seated. I haven’t given this a lot of thought since then, but wanted to revisit it now that I’m in the Master Gardener class.
Materials for one 5’x3′ bed
- Four 1″ x 6″ x 8′ boards for the sides of the box
- Four 2″ x 4″ x 10′ boards for the bottom of the box
- Five 2″ x 4″ x 8′ boards for the legs and bracing
- One roll of screen that is at least 3′ wide and 5′ long for the bottom
- 2-1/4″ wood screws
- About 12 cubic feet of top soil or fill
- Optional – Three 6′ lengths of foam pipe insulation for 1″ pipe for padding along the edges
A few notes:
- We made our beds 5’x3′ because they are only accessible from one side and the narrower width would be easier to reach across. A 4’x4′ bed could be made the same way, with only slightly different supplies.
- Refer to the sketches at the end of this post for additional detail.
- We originally designed the beds 2″ taller (28″ clearance between the ground and the bottom of the bed) based on the ADA accessibility guidelines for adequate knee clearance for people in wheelchairs (27″). This turned out to be uncomfortably high for people standing. We measured a few wheelchairs and shortened the beds to have 26″ of clearance, which was an improvement for both sitting and standing. The instructions below are for 26″ of clearance.
Part 1: Assemble parts for box
1) Cut the 1″x6″x8’s into two lengths: 5′ and 2′ 10.5″ for the sides of the box (see sketches at the bottom of post).
2) Cut the 2″x4″x10’s into 4’10.25″ lengths for the bottom of the box.
3) Screw the boards together to make two 5’x3′ rectangles. If one side of the lumber is rough, make sure to have that pointing inside.
4) Measure the width of the rectangle, and cut two pieces of that length from one of the 2″x4″x8’s for bottom braces.
5) One of the rectangles will become the bottom of the box. Screw the 4’10.25″ 2x4s into the bottom of the rectangle. These will hold the soil in place. Because our garden beds were only going to be accessed from one side, we put the boards together tightly on the “front” so that water wouldn’t drip onto people’s laps as they worked. Then, on the “back” side, we spaced the 2x4s farther apart so that the bed would have adequate drainage.
6) Screw two braces to the bottom of the box, about 6″ from the ends.
Note: This is a good point to stop and order pizza!
Part 2: Assemble legs
7) Cut each of the remaining four 2″x4″x8’s into three lengths for the legs and braces : 35″, 12″, and 24.5″ (see sketches below for angles).
8) Screw the 35″ and 24.5″ pieces together. We put a 45-degree cut on the 35″ length so that it would look a bit nicer as a finished product.
9) Attach each of the legs to the bottom half of the box. Each leg will support the crosspiece that is attached to the bottom of the box, making it 26″ from the ground to the bottom of the box
10) Slide the top rectangle into place and screw it to the outside leg.
11) Flip the bed over and attach a brace to each leg.
Part 3: Add soil
12) Cut a screen to the size of the box. Pull tight and staple.
We used regular window screen, which worked pretty well to hold the soil in place. We were worried that some soil would work its way through the screen after a rain, but we visited the beds after a few rains that the pavement below them was clean.
13) Make sure the bed is very study, and add or tighten any screws.
14) Move the bed to its final location. Make sure that the good side, if you have one, is pointing out. Check and make sure that the legs are perpendicular to the ground. If you are on a hard surface, you could bolt the legs to the ground.
15) Fill the beds with soil. We used a mixture of cheap, bagged top soil and manure, alternating the two and mixing as we went. The soil was very dense and not the easiest to work it. It may have worked better to mix in peat or some other materials to add organic matter to the soil and reduce its overall weight.
16) Plant and tend!!
** Here are the sketches!