Question
I just wanted to see if you would have any more information for me on my tulip tree that is not flowering.  The tree at this time is about 5 to 6 years old.  I received an answer from Tom Alonzo and he had asked me to contact you for more information. Hope to hear from you soon.

Thank you,
Eileen

Answer
I am assuming you have a tree called tulip tree or yellow poplar Liriodendron Tulipifera  There are other trees called by the name tulip tree--saucer magnolia is one.
Yellow poplar produces a few flowers early but it usually takes about 10-15 years for many flowers to be produced. You can speed up this process by fertilizing the tree. The most crucial fertilizer ingredient for promoting flowering is phosphorus, as phosphorus helps to maximize the amount and quality of blossoms that form. For this reason, if you want to increase the flower production of a flowering tree, the fertilizer you use should have a high percentage of phosphorus and relatively lower percentages of nitrogen and potassium. Examples include 5-30-5 and 10-52-10.

I would use 1 lb per inch of trunk diameter scattered around the tree and watered in good. Go ahead and fertilize now and again in the spring. It still may take a couple of years to see results. The age is the determining factor for flowers. Check with your local garden type store for this fertilizer. I recommend granular fertilizer.