Wisteria

Twelve years ago, I bought a sweet little wisteria vine just hanging with blossoms. I planted it in my garden and over the years, it has grown over our front porch shading our wicker rockers and providing a nesting home for a family of robins that return every spring. I have pruned and fussed and cut it back and let it grow, fertilized and left it alone...with nary another bloom. HELP!