Tropicals & Tender Perennials: Brug Not Blooming?, 1 by Marlene4

Marlene4 wrote:
Greetings,
I received a gift of a brugmansia, dr. seuss, last fall. When I received it, it had been cut below the Y, which I understood, to be an excellent thing for blooming. I kept it carefully, then when the weather warmed up, I set it out. I transplanted it to a garden box along with a few other plants. The Brug gains and loses leaves but does not want to flower at all. It is in a good bit of sun, at least 6 hours per day.
Can any one tell me what is going on? Have I overcrowed it? Is it in a deep enough pot? Anything else that I may not have thought of?
Please let me know what you think.
Cheers!
Marlene