Guerrilla Gardening With Fruit Trees

Most of them do.  Sometimes they are chopped down by the parks department.  Like I said, it's about climate, drought tolerance, amount of sun/shade that it receives. On some, I will water them for the first year.  
John S
PDX OR

Off topic but did Fukuoka include fruit tree seeds in his seed balls? I understand that with seed balls, plants probably get naturally thinned out with the weaker slower growing plants growing in the shade of another plant thus  more likely to be eaten by insects because it's weak. But how would this work for trees that are growing too close? I'm sure that in a forest, eventually over a hundred year or so trees naturally thin out to their optimum spacing with weaker trees dieing earlier and the lucky trees that are spaced out more evenly grow healthy. But wouldn't this process take like a hundred years? My question is when doing Fukuoka gardening , how do you approach planting fruit trees? Would Fukuoka just include them in his seedball which probably would result in overcrowded fruit trees or would he manually plant them perfectly spaced for his orchard?

I'm not sure about his style of gardening, so I can't speak to that specifically. However, I do know of people planting trees by seed in clay cubes in arid regions without watering and the trees have sometimes made it.

As for tree spacing, that's more complicated from what I've seen. Sometimes people get away with spacing trees closer together. The trees adapt as they grow up and are fine. Yet sometimes overly dense plantings cause the trees to be stressed out and compete too much for resources like water. In the Pacific Northwest, for example, the summers have gotten drier and hotter, which has stressed the trees more. Personally I would go for a planned spacing just to be sure, but plenty of people are more experimental and it works for them

Ok here's my plan to create a covert urban orchard. I have used my city's GIS to locate all of the flowering crabapples in town. I will start close to my house and graft onto a few of the branches using apple scion wood from my own tree pruning. I figure it will be easier to use the existing trees and graft rather than attempt to plant new trees and hope they don't get mowed over or eaten by animals.  If the city employees find out about them, they'll probably get chopped off. I'm ok with that, I just need to use the trees that they won't find. I can use brown elastic that will more or less camouflage the graft union. If I use a bright neon-colored elastic, it'll be easy to spot and likely removed.

I'd probably feel bad about doing this if I were to just abandon the grafts and let the apples fall and make a mess. But as long as I keep the trees close to my house, I'll be able to take care of any pest management and harvesting just as I do for my own trees. I think of it as an extension of my own backyard orchard.

The dream is to one day be able to harvest enough fruit to provide to the local food bank or a homeless shelter.