It doesn't seem to have much potential for an ecosystem-based agriculture and I can't seem to find a plant that can survive its ailanthone.
I'm okay with planting the bad guys, like butterfly bush or black locust or willow or nearly any herbaceous weed, but this might be outside my comfort zone. For now it stays in the pot on top of cement.
William James wrote:I finally got my hands on one, but now I'm having serious doubts about planting it. All the literature says not to plant it, all parts of it seem alleleopathic, which might rule out using it as soil-building mulch. And once it's in the ground you pretty much can't get rid of it.
Based on my experience with ailanthus I think it's allopathic nature is overstated. The towering tree in the picture above is close to my forest garden where I grow all kinds of stuff without any noticeable problem. I have strawberry, basil, tomatoes, mints, service berry, snap peas, lavender etc. all growing less than 15 feet from the trunk.
This tree suckers from the roots and will form a colony if you don't weed the suckers. I would personally not plant this as anything but a windbreak or first pioneer for organic material in depleted soil. It spreads just as easily by seed, but the seedlings pull out of the ground root and all pretty easily. It's always a strong tree but in some climates I think it can really grow super fast and dominant.