Elderberry trees don't always make berries. I've looked into this, because I have one that doesn't. First, they prefer a pH of 5.5 to 6.5...but they're supposed to be adaptable to some areas with higher pH (fairly high pH around here). Then there's cross-pollination, which I think is what's wrong with mine. There should be two different cultivars within 60 feet for adequate pollination. I've moved suckering plants from mine out by the dry creek on the corner of the property, but that doesn't count...they are clones of mine. As far as I know, there aren't any other elderberry trees anywhere locally.I really need another kind of elderberry!