My Agapanthus won't bloom!

I have three very large pots of Agapanthus that I have nurtured for years The first few years I got 25-30 blooms per pot. Each year, for the last three years, I have only had one or two blooms per pot - one pot has not bloomed in 3 years!). Since they are not hardy, I winter them in my basement, then cut back and put outside in the spring. I've tried everything I can think of to encourage bloom. I've read that they like to be potbound, so I have not divided them in several years (I started with one pot, divided 5-6 years ago to have two and was given the 3rd pot by a friend who could not make it bloom). For several winters, I let the pots sit in my cool basement, in the dark, all winter - I let them dry out and wither. In spring, I cut off the dead leaves and brought out to the patio to grow. Seeking a solution to the lack of blooms, I put them by windows in my basement last fall and kept them watered (lightly) so they held their leaves. I'm ready to move them out today, but I'm not sure they're going to bloom this year either.

Anybody have the secret to making Agapanthus bloom?

I'm curious to read responses as well. I've never had any experience with aggies, but have started some from seed that are doing well. While I've assumed I'll have to overwinter like you've done, I may experiment with their hardiness with a few. It will be a few years, I imagine, before I'll see blooms, but hoping I have the swing of growing them by then.

Have you tried Osmocote? Works well on my potted plants.

I haven't tried Osmocote. I've used both MiracleGro and Peters (different years) on them in the spring, and always have lush leaves, but for the last few years, only one or two blooms. I'm ready to give them away!

Time to split them up and keep the newer (outside edge of clumps) plants. You can always trade away the excess? Too bad tho.

eye candy, this photo has nothing to do with the topic being discussed...

I wonder if one of the bloom booster fertilizer products would help? Shultz, Miracle Grow, and other brands have a version of similar products.

I think you should consider not feeding them at all as they will just grow more leaves at the expense of flowers. They like hot dry conditions and like to be potbound and once planted not moved. If you are cruel to them they will reward you more!