That article confirms it I think. It has never set seed, and they do address the graceful aspect, which sounds so much better than twiggy, LOL. I has remained at about 4' tall, but has gotten wider, which sounds right on. Mine is in partial shade, and blooms its heart out, another thing they mentioned. Now, sounds like I need to figure out how to propagate this apparent gem! You, our resident Lilac Queen, must have one! I believe I will try layering it.