Pirate farming is where you plant edibles in what you might consider hidden or abandoned areas.

The idea is that you keep the seeds of things you eat and then plant them out and about. You don't do anything other than plant them and let them grow. You don't get hung up on harvesting either as you accept that many will not germinate, the birds will get many, other animals will get their share and anybody else who comes along may take their fill.

Some obvious caveats:

1. Many monoculture fruits/veggies will not germinate or will not fruit because they've been modified that way so this will work better with heirloom varieties and natural/wild foods.
2. For some plants, you're going to have to plant alongside support and be mindful of sun/shade, etc. Even though you're not tending to the plants, you're not just blindly broadcasting either.
3. There will be much more unmolested space in rural or small town areas than in cities. In cities, you might want to concentrate on root crops, greens, and native/wild edibles. You can also hide food plants amongst landscaping in many instances.
4. You'll also want to be mindful about where NOT to plant, especially in cities. You don't want to break through fencing, for example plant in toxic or contaminated soil.

Most pirate farmers are either people who do not own land, are migratory, or focus mostly on providing foods to wildlife.

It seems practically tailor made for collapse, doesn't it?