Guerilla gardening is find a scrap of land that’s being wasted and turn it green, in the hopes that whoever owns it won’t care or can’t be bothered to tear up what you’ve planted.

Whatever it is that you plant, if you intend for it to be a source of food or shade, you should intend for it to be permanent, and able to survive without your continued care. Ideally fruit or nut trees, berry bushes if trees are not an option and if all else fails perennial vegetables, herbs or flowers. Even something as simple as clover is going to help your local pollinators. Time is a big factor. Do you expect your plants will last a season? Will they get dug up next year? You don't want your effort, or these plants, to go to waste, so don't commit a row of fruit trees to the earth when you know soon enough they would be destroyed mindlessly. If all you've got is a summer, go ahead and plant annuals. Throw down those tomatoes, plant some corn. Be showy, so the locals begin to realize what could have been.

Regardless of how long you expect your gardening to last, how you go about it is another key idea. There are two simple ways: you belong there, or you were never there.

You Belong There:

This is an easy enough outfit: jeans, work boots, and a reflective vest will keep most people from second-guessing you. If more than one of you are out and about on a piece of land, try to match your shirt to add even more legitimacy. Cap this off with a truck and some equipment and you'll be virtually invisible to anyone. Make sure one of you is doing all the work while the other lounges by the cooler with some Oakleys on.

You Were Never There:

Obviously enough, here you're trying to not be seen. Plant at night or in a secluded area. Guerilla gardening doesn't mean you're just taking over a median or a patch of grass beside an exit - you might be taking advantage of extant green space, as well. Say you've got a patch of park that's disused, and nothing but grass? Make it worth the space. And again, it doesn't have to be an orchard to be successful guerrilla gardening. Red clover can go a long way toward improving soil, and helping out the area bee population.

If you're planting near roads or industrial areas, it's best to test the soil before you try to plant anything edible. If the soil is in question, there are a variety of plants capable of phytoremediation - meaning the plant can help clean up the place. Just be sure to pull the plants and dispose of them properly rather than let them decompose in place, thus returning the contaminant to the earth.