Hey Karyn, Theres small specimens around that give a stunning display of blooms here in Cal, probably at around 10 feet. Keep in mind though that these are in ground trees, not in pots. I think that it is possible to grow it in a container though because it is sometimes used for bonsai. It would probably just take a little longer to bloom than a non-stunted tree. just my two cents.

Hi
Over the years have tried to dwarf many types of tropical trees Mainly because I live on a postage stamp lol.
Have no experience with the type you name .But have found some that dwarf very well while others grow well but don't flower well or not at all. Have a white form of a Delonix regia grown in a pot for around 11 years ,Has yet to flower.
You might check on your particular species as a true Bonsai. It see if it actually does well . At least you'll have some info on your own growing conditions.
You'll definitely want a plan lol. That tree is GIGANTIC.
lol gary

Thanks. I still can't figure out what possessed me to grow that tree. lol I've been racking my brain trying to remember where I bought the seeds. I figure the description will give me a clue as to why I started it. It has beautiful foliage and an interesting shape but will soon outgrow the GH if I can't keep it pruned to a manageable size. I have another sapling that I believe is another type of Australian bottle tree growing that's much smaller but the tag has been lost. I'll have to get a pic and get someone to ID it for me. Hopefully it can be identified without blooms.
Karyn

Hi
Since you already have the tree and it must be grown in a GH. Not many options because it does get gigantic for sure.lol
I find almost all will grow severely pruned even to "Bonsai." What they don't do is flower well
The other poster gives you some hope ?? What have you got to lose??
Isn't it fun researching tropical plants?? There's always another species lol
In my case I bought the seeds listed as "white form of Delonix regia" There is a separate species called "white delonix" apparently it is entirely different than regia.
So do I have white form or white delonix.?? There are some striking differences in growth habit and arrangement of leaves from the delonix I'm familiar with. But it is growing in a pot and has been root pruned several times.
Flowering would tell me for sure as they are very different or at least appear to be from pix.
Anyway good luck with your problem . 15 feet would be about 10 percent or less of normal growth?? that is a glorious tree at least from the pix I've seen gary

The Flame tree will grow even in temperate climate , as it is the floral emblem for my local area I did some research on it and was very surprised at the extant of its habitat .
It grows from the true wet tropics here in Queensland , way down to the Illawara region in NSW , thats nearly 2000kl. I have a 10 m one in my back yard , and it is leafless now , looking forward to another great display of flowers .

Here is a link that might be useful: Oz Native thread on Flame tress in temperate