Along with Bill's marvelous raised bed or as an alternative, a person with disabilities might want to consider vertical gardening.
Many vegetables and of course, fruits and
flowers, can be trained to grow in this manner.
While planning a vertical garden either alone or in conjunction with a raised bed, planter box or other container, you will need to keep in mind two important things;
1) How high you can safely and comfortably reach and
2) the stability of the vertical structure to avoid accidents.
Consider the possibilities for vertical gardening: there are trellises of countless designs and materials, A-frames,fences and fences with twine and poles added, towers, teepees, stakes and cages, netting and elaborate systems of ropes and pulleys, all the way to espaliers and cordons.