Fruits and Nuts: How Do I Coax a Honeybell Tangelo to Bloom?, 1 by RxBenson

RxBenson wrote:
My plants are at least seven years old, started from seed. (The first one I ever ate had seeds, but almost all since have been seedless...) They are together in a tub and will probably need potting-up to larger accommodations this spring as they are almost 4-ft tall now and quite fully branched. (The photo is from April 2013.)

They spend the winter on the floor in front of an east window. (They used to be on the sill....) Their summers are spent in the yard here in Zone 7.

I know that late winter is their bloom time in their native FL habitat, but I have never seen any semblance of intent to bloom from them here in MD -- or in NJ where they began.

Do they need a winter chill rather than room temperature? Grow lights? Are they too immature to bloom yet? I don't dream of raising my own fruit, but I would adore having them flower. Is there a fertilizer trick or a photo-period problem?

Thank you for all assistance.

Roxanna