Off-grid vs RV park

If you can't go the box planters like muddydogs suggested, do some research on growing veggies in pots. there are lots you can grow if you sit several flower pots around. by using pots, you may have to water more frequently or fertilize (you can do it organically) but you can have veggies without the permanence of regular garden. My mom grows all her tomatoes, peppers, etc in pots rather than the ground, just because it is easier. Good soil to start, no digging holes in clay and then soil conditioning and she has less weeds. With pots, she can move to adjust amount of sun/shade, if a plant isn't doing well and watering pots actually uses less water than watering ground. (She uses old coolers, that have broken handles, hinges, etc.. helps insulate the roots both winter and summer. She has these in back yard of house, where they are not visible to street.. you may not have that option).