Passion Flowers Won't Bloom

I have grown a passion flower from seed, it is now in it's third year in my porch and has not had one single flower, I do feed it regularly on a mixed feed for both growth and flowering.

Passion flower needs a great deal of light to bloom. A south window would be the best spot for the winter, out of doors probably best for the summer. To make up for a possible lack of strong light, fertilize with a high phosphate fertilizer such as "Blossom - Boost" and try for either no nitrogen or at least very low nitrogen in the fertilizer. This means, in the three number rating given for fertilizers, the middle number should be high, the first number much lower or even zero.
One of our customers who summered his passion flower out of doors had it set buds out of doors, but then drop them when moved back indoors - probably because outdoors it was cool and moist, but indoors it was hot and dry. It would therefore be a good idea to use a sunny but cool room and a pebble tray with water under the plant to move the plant to when it becomes too cold out of doors.