Hello to all who will listen. I am new to this web site and know practically nothing about trees and plants. But, I do know that I love my Fringe tree (old mans beard/blooming ash?)

I was given a sprig or cutting off of a well developed tree and planted it about 15 years ago in my front yard. It gradually took off and I actually saw and smelled the beautiful white fringes that came out at the end of may. The tree only got as tall ad about three feet. My wife thought it wasn't growing any longer because there was another plant or tree next to it, so she moved the other plant/tree away from the fringe tree. The fringe tree then took off very well and stands about 20' tall. However, ever since she moved that other plant/tree away from it, my fringe tree will not bloom with the white fringes any more. The green fringe pods grow but never open up to reveal its beautiful ferrules and aroma. Someone please help me to get my tree back to blooming so I can see the white fringes dangle and smell that Godly aroma again. Thank you so much.