One idea- you could figure out the dimensions you wanted and ask the local Boy Scouts to make them for you out of plywood using concrete blocks as legs. They would need to be at least 12" deep.
vickie

Buy a 50 ft. roll of turkey wire 4 ft. high with 2" x 4" spacing. Cut it in three 15 ft. lengths with 2" extra wire sticking out at one end to hook onto the other end. Bring the ends together to form a large cage about 4 ft. in diameter. Use the 2" piece to hook the ends together from top to bottom. Now weave vertical blind slats in the fence wire horizontally all the way around from top to bottom to make a large basket. This 50 ft. roll will make you three baskets. Be sure you locate each basket on level ground. Fill each basket with leaves,any kind except pine needles, and keep adding leaves for at least 2 weeks as they settle. This is very, very important because the leaves will pack down like a sponge. At the end of 2 weeks put at least 6 inches of planting soil on top covering the entire surface over the leaves. You must plant now because the weight of the soil will press the leaves down further and it will be hard to plant reaching over the fence wire after it settles. It will continue to settle for about 2 to 6 weeks depending on the type of leaves and the amount of rain. It should stop settling at about a 3 ft. height or waist height, ideal for those using wheelchairs. After the soil has settled to this point cut the top 10 inches of the fence wire off leaving 2 inch pieces sticking up all the way around, about 90 pieces. Bend these down inside to avoid being cut by the sharp ends. Save the part you cut off for use later. In 2 to 3 years it will have settled to about 2 ft. or less. This is slow composting also known as anaerobic digestion. In the end you end up with good humus. When you are ready to start over just lift the wire cage off leaving a large cake of humus, set the cage in a new location, put the 10 inch piece back on top, fill it with leaves, keep adding leaves for 2 weeks, add 6 inches of soil and you've started all over again. Plant.

I forgot to mention that the roots of the flowers or vegetables will feed off of the nutrients in the leaves of the large basket gardens. The leaves also hold a lot of moisture depending on the amount of watering or rain. Some of the leaves will hold water in a cup shape inside the cage and after a hard rain I haven't had to water large plants for a month. Signed: Anaerobic.

Neat idea, anaerobic (so that's where you get your name from!). I have even seen bags of sand used as a wall to build raised bends.

One of the difficulties of raised beds for wheelchair bound gardeners is it is difficult to work from the side all the time. It is nice to be able to pull the chair beneath a table type structure.

If you can't have a table like structure, I say plant vegetables in pots and put them on stands to make them accessible or make them light enough so that someone could place them on a table for the wheelchair bound gardener to work on.

I am in no hurry for compost or humus. The idea behind the Large Basket Gardens is to support the raised beds with the compressed leaves as long as possible. In the end the result is a high quality humus. While the plants are growing they will feed off of the nutrients in the leaves. The leaves in a cupped shape will hold water for quite a while and I have't had to water large plants for up to a month. When the soil has settled below the 3' height the sides will keep plants. The big advantage or this type of raised bed is that many handicapped persons can take care of planting, weeding and harvesting at a waist-height level. I realize that most people are in a hurry for compost but this is another ball game altogether. This is not the normal way to make compost I know, and by the way, composting is aerobic. The Large Basket Gardens are not exactly composting. This is known as Anaerobic Digestion, no air, no turning, no work, no hurry. But in the end you still get the same thing, good old humus. Signed: ANAEROBIC

Contact the various service clubs in your area, like the Eagles, Elk, Moose, Lions, Kiwanis, etc, and ask if they could make something like this for you. BE SURE to have the design and measurements already drawn up.

Ask for donations of soil, compost, etc.

Sue

I just built some planters based upon those posted by the American Horticultural Therapy Association
here : http://www.ahta.org/AHTA Raised Bed.pdf

They take a LOT of soil to fill!!!
However a very rewarding project.

pictures of the project are posted at the link below

Here is a link that might be useful: Theraputic Garden

A less resource-intense method of providing raised beds for mobility impaired people is laid out in Mel Bartholomew's recent edition of "Square Foot Gardening." Basically, the beds are made with a bottom, including drainage holes, and placed on sawhorses or other, more sturdy, supports. Bartholomew provides photos.

His website also gives ideas about this: www.squarefootgardening.com

in el cerrito

My father got himself onto the garden committee at the assisted living place where he lives, convinced them to create gardens, and has slowly but surely been expanding the space. His design is for a 4 x 8 raised bed that's about 30' high. They're made with plastic "lumber". as you can see (if the link works) some people insisted on 8 x 8 beds that are about 12" high. But many are now realizing this isn't a good idea because they can't reach to the center of the bed.

He usually works his garden by sitting in his walker, so it should work for people in wheelchairs.

I took this photo the day after his 85th birthday BTW. He took on a second plot this year, and grows potatoes in addition to radishes, onions, lettuce, carrots, beets, tomatoes, and summer squash.

Here is a link that might be useful: Tor's garden

I read where old chest-type freezers have been used for raised beds at a nursing home. That would be a good way to recycle them. I'm not sure what they did for drainage, other than the drain hole in the bottom of them. You could even surround the exteriors of them with a picket fence to improve the appearance.