My brother owns a funeral home. When he bought it, there were numerous vaults stacked behind a big ambulance barn. A vault is used to contain a casket when someone is buried, ostensibly to contain any formaldehyde from embalmed bodies. While talking to him one day, he bitched that he had to buy more vaults because “these last 5 aren’t up to snuff”. He explained that whoever designed them had made them of plastic with double wall construction, and then injected the space between walls with foam. Essentially, they were made like a fishing buoy, and he was not risking legal action against his estate if they ever “floated up”. I volunteered to take the 5 ‘under-snuff’ vaults off his hands.
We use them to catch rainwater from the roofs, but the lids of these things were not really usable for much, being built like a shallow ribbed bathtub. I thought about using them for a roof, but they weigh about 80 lb. each – and no way to really join them and have water flow off effectively.
Now, being as I have my robo-hip and robo-knee, and I don’t want to wear out their artificial cartilage too soon, it occurred to me that I could make them into a sort of raised bed gardening setup. So I did exactly that.
I used salvaged, treated deck lumber (Craigslist – we tore the deck out and kept the wood) to make a frame of 2×6, and then used 4×4 posts as legs. I set the height at 34 inches for the legs, and used 3” and 1-1/2” deck screws to assemble the frames. These frames are 36” wide and 7-1/2’ long. I built a shelf on each end to make transplanting and dirt work easier.
I bought a nylon tow rope for $9 at Dollar General. This was rated at 4500 lbs, so I knew it would hold the vault lids even filled with water. I used 3 straps for each one to spread the load.
I doubled the ends of the cut straps, measuring so that the span was uniform, but left 6-8 inches of length at each end of every strap. This allowed me to double the ends back on themselves. The reason for this is the constant weight pulling on the nylon would eventually stretch the screw holes. But if the ends are doubled, then if the top layer stretches, the other layer tightens. I used deck screws with washers to help spread the load a little more.
I painted these “grow benches” with alkaline enamel I bought at the paint store for $5 as mismatched paint. It is green or greenish and that is good enough for me. Brown or gray would be as good, but the reason I painted them was because it was recycled lumber, and in full weather, it will degrade faster unpainted. I also painted the exposed nylon strapping for the same reason – UV protection.
I set the first one up, leveled it with rocks and a little digging, then slid the vault lid into the frame. I drilled 3/4” holes in between the largest reinforcing ribs. I covered that with 3 layers of aluminum screen, then covered each of the screens with pea gravel. Now the water could drain and root rot be avoided (been an issue last couple of years as we have had record rainfall).
I loaded it with a combo of: peat moss, cow manure, top soil, a little sand and Osmocote. I let the weeds from the topsoil sprout in the fresh, loose soil and then plucked them all out – it was very easy and zero backache or knee pain.
So now, I have 4 of these up and have run out of scrap lumber. But I will get the final one done as soon as we get new tires on the F250, and can get more Craigslist free deck lumber in Houston.
I am pretty happy with this setup. I don’t have to bend to weed these beds, I can see the plants at chest level so checking for bugs is dead simple. When I need to turn the dirt, it can be done with a garden claw or a trowel instead of a tiller, and I don’t have to worry about gophers. But the main reason for doing this is the ease of use it makes for guys like me, who aren’t aging like Benjamin Button…
This same thing can be done using plastic barrels, but if you opt for that, I recommend using food grade blue plastic or else that harder gray or maroon barrel they ship sausage casings or other wet food products in. Both of those can take the UV rays for years and not degrade much. I plan on doing a smaller ‘grow bench’ with 2 old blue water barrels we used before we had water on the property. This will be smaller, but it is a good use for those barrels now that they are just sitting there.
I imagine you could use a large tote similarly by cutting it in half and just making a stand for it to sit on. I do recommend you make the final height from 32”-36”, depending on who else is using them. And by that height, I mean the level of the dirt, not the legs. This lets the plants get 3’ tall and still be easily reachable and workable.
Remember – for most vegetables, a foot of good soil is sufficient. No need to make these things much deeper than that.
This is what I think “Raised Bed Gardening” should be, instead of the 1’-2’ high versions. I have tried that, and that height is too low to work the soil easily without bending at the waist for an hour or staying on your knees. 1’-2’ high is also plenty low enough for dogs to run through or cats to leave you an unwanted present, so this increase in height helps with that, and small kids too.
One final way you might do this on the cheap is to buy used 3/4” plywood and simply make a raised box. In Houston, used plywood sells for $5 a sheet, and usually it is only the corners or edges that are problematic. A circular saw will cure that, and making them 4’ wide is too wide to work effectively. And the dirt/water load (rain) will require a lot of bracing at 4’ wide. After you build the box and legs, buy used billboard canvas and use that as a liner inside the box. Modern billboards aren’t painted, but are printed on waterproof canvas that is then hung and stretched on the billboard. When the billboard is changed out, there isn’t much one can do with it. But for this, it would work great. You can find these on Craigslist in most big cities. Most any advertising company will have them, even in smaller towns.
This is a great thing to make for aging parents or grandparents, who mainly cease gardening due to the difficulty in doing things like weeding and soil work. This increase in height changes a lot of things from traditional gardening methods. And like I said – I think this is what raised bed gardening should be, and my robo-knee, robo-hip and 4 herniated discs agree!