When people first think of wheelchairs and planter boxes, they visualize something like a raised box that a person in a wheelchair can 'drive' under, so they are facing the box. While not impossible, it does complicate the design and increase the expense. The boxes themselves would need to be at least 8" deep (10" would be better), about 3 ft wide, and as long as practical, depending on where they would be placed. The boxes would have to sit on a frame, and I think that's where the problems would come in with this design.

Most wheelchair seats are about 19" from the ground. Allowing 6" clearance, that would put the bottom of the box about 25" from the ground. If the box is 8" deep, the top edge of the box would be 33" from the ground. This is about chest-high to the person in a wheelchair. If you used 2" lumber for the box (for strength and rigidity), the top of the box would be 34.5" from the ground. This is getting pretty high for a smaller person in the chair.

Even using a lightweight soilless potting soil, with water added, you would have a pretty heavy box.

And it would need drainage. You would need some kind of specific drainage, not just perforations, so the water wouldn't drip into the laps of the person in the wheelchair. It would have to gather in the center or something, and drain down via a tube or something, probably into a bucket. Then you would need the supports under the box. Two-by-fours would be the smallest you would want to use. To allow for rolling the wheelchair under the table, you couldn't have any crosspieces that would brace and stabilize the legs, and I suspect the weight of the moist soil would tend to make the legs want to spread outwards. After some period of time, this could be a danger if the legs spread out enough to allow the box to collapse on top of someone sitting under the box.

Personally, I would make the boxes so they almost sat right on the ground. 'Almost' because I think they should be elevated on 2x4s for good drainage. These boxes could be 24" high, which would be a good height for most people in wheelchairs. (Actually, it would be about 25.5" high with the 2x4s underneath.

The person in the wheelchair would have to park alongside the box, but I think the lower cost and higher degree of safety would offset any small inconvenience.

Even this wouldn't be cheap. If you used something like that Trex deck material (composite boards of wood & plastic), one box would cost about $280 for the side boards alone (for a box 12'x3'x2'), never mind the braces, screws, etc. More if a bottom was built in (maybe about another $250). You could use cedar or some other water-resistant wood if it was available in your area, or you could use pine or fir, and line it with heavy sheet plastic.

Then you would get to fill it. The box with the above dimensions would hold 72 cubic feet of potting soil (or a little less, since you wouldn't want it right up to the very top). Sixty-six cubic feet (2.5 cubic yards) would be 33 bags of potting soil of the large size (2 cubic feet). That's about $400 worth of MiracleGro potting soil. If you could find some good soil mix in bulk (by the cubic yard) at a landscape materials source, it would probably cost closer to $65 to fill the box.

Unless you're getting some really good donations of materials, you're looking at a lot of money.

Still with me? Why not consider livestock water tanks? They come in plastic or galvanized steel, and while they're not as big, they're decently good-looking, long-lasting, and are designed to take a lot of abuse. One useful size is 6ft long x 2ft wide x 2ft tall (about 20 cu ft or .75cu yard) (see link below) for $135. The plastic ones go up to about 300 gallons (40 cu ft or 1.5 cubic yards) for $210.

These already have drainage built in. I would raise them off the ground by setting them on 2x4s.

The problem with the stock tanks is that there is nothing for the Eagle Scouts to build, unless you got the ones that are only one foot tall, and set them on sturdy stands. The advantage is that you could provide several tanks in different locations.

Whichever way you go, try to solicit donations of materials or tanks. Tractor Supply Co. has bought out many smaller feed stores all over the country. You could offer to install a sign on the tank or box a company donates to your project: "Materials generously supplied by Lowe's" or "Containers generously supplied by Tractor Supply Co." Some free advertising can't hurt.

Sue

Here is a link that might be useful: Six foot galvanized stock tank

Thanks for threads and reply made in this forum is beneficial for us.

I like the idea of the side access planters. Everything out side gets lots of spiders, including black widows, in this area and the thought of legs and laps under a dark table top just freaks me out.

In addition to all the practical engineering of tables.

My family has build lots of raised beds with pallet wood. Only lasts three to four years, but it's free and if you read the codes right, untreated with chemicals.