Ginger flower (butterfly lily) won't bloom?

Question

i have several pots of white ginger flower, or so call the Btterfly Lily. unfortunately i live in a condo, i have a concret back yard, i have to grow them in planter.
they grow very tall and lush but just won't bloom!?
i had them for more then 3 years now, i got a couple of bulbs during these time, very frustrating.
i love the fragrant, we have these flowers back home(taiwan) and i really miss the smell of it
the planters are on the east side of the back yard with tree shade half of the day. i water it regularly
http://www.tropilab.com/butterflylily.html

Answer 1

How big of a container do you have them in? A plant that large is certain to need at least a 25 liter container or half barrel to do well. I'm not that familiar with Butterfly lily, but I know of other plants that will not bloom if they are root bound. Their roots need a lot of room to spread out. I wish I could be more help, but that is all I can think of since I've never grown a butterfly lily. Have you given it fertilizer?
Good Luck

Answer 2

It is extremely important to make sure there is good drainage where you plant your bulbs and that you fertilize the bulbs 3 times with a well-balanced 10-10-10 fertilizer. Fertilize once when planting, once when they just come above the surface, and once right after flowering.

Container plants cannot get all the nutrients they need after about 3 months, so you need to feed them.