I could plant it in between plants that don't go dormant instead of having a bed of entirely curcumas if they all get bald. That way, if the curcumas go into dormancy, there would still be foliage to cover-up the bare spots. Will the curcumas just suddenly sprout up again after their dormancy is over? I would still have to water the other plants that aren't dormant, is this ok? or will it kill the dormant rhizome or something?

In zone 9, they all go dormant and just fade away. They return for me starting in March, but each one has its own schedule.

Dormancy in our zone blew my mind too! Lots of the gingers do it though- globbas and pinecone gingers, some Hedychiums etc.
My curcumas get watered while they are dormant- no problem.

You have the right idea-plant them between other things, so you don't have an empty bed all winter.

Hi
I'm not sure if all curcumas go dormant but the ones that I have do. They are just waking up right now . They slowly die down in late Dec. If your set on gingers there are hundreds of varieties many of which do not go dormant.
In the Phillipines I wouldn't know what to suggest but geez there are hundreds if not thousands of plants that should thrive in your climate. gary

Here in Costa Rica they don't go dormant. Even in the very dry season, they are fine, but with some additional water they should produce blooms year round. Some of the them, such as the various Costus species I have propagated but cutting the stalk into six inch lengths and put the pieces right into the ground. In fact, all my costus plants were started that way.