I'm reading all about Black Locust and am very excited about the prospects of this amazing tree. Nitrogen fixation, naturally preserved, hot burning wood all sound fantastic. I'm thinking of eventually working it into a food forest for nitrogen fixation on some georgia soil that was depleted from the bygone intensive cotton farming days. I'd also love to make fence posts out of it. I guess my questions are, based on any anecdotal experience folks have with it, the following:
1) Does it take over and become invasive like sweetgum or privet? If so does it just attack disturbed soil or does it creep into old growth forests as well?
2) Has anybody been able to grow lumber straight enough to make fence posts from it? About how long did it take?
3) If I raise a few cows in the same field that its growing in, will it kill em if they decide to munch of the leaves or beans?
1. It sends up suckers and seeds profusely after a while, but I don't think it would invade old growth forests as it really only does well where there's not a lot of nitrogen. It's not really shade tolerant, definitely an early succession tree. Of course, it's also native where I live so I don't worry about it.
2. Yes, that's pretty easy. Fence posts don't need to be perfectly straight anyway. I've built 2 arbors with black locust logs. Takes about 5 - 15 years for posts depending on how big you want them.
3. No. If they have access to other foods they'll only eat as much of it as they can tolerate.
"To oppose something is to maintain it" -- Ursula LeGuin
Hardwood cuttings planted directly in the ground will take, I haven't done this a ton, but I've had about 50% success.
Also, stooling works very well, and depending on the situation they may root sucker aggressively when coppiced, in which case you can dig up suckers and just let the original grow, then repeat annually. Around here stump sprouts and root suckers will grow easily 7-8' in the first year.