I think they could use some Miracle Grow once a week and some time release fertilizer 3 or 4 times during the summer. They need lots of fertilizer. It is not too late. Start giving them fertilizer today and by August you will have blooms. And pour on the water.
Mine do not bloom til August here in Ga. or sometimes later.
The part sun may be a factor. They like full sun.

It sounds as if you are doing everything right for them to bloom and I think they are going to burst forth soon. I live in San Antonio and I suggest that you do NOT grow them in full sun or they will turn crispy. My heydichiums are just now starting to bud although Kaempferia started blooming a couple of weeks ago. It will happen for you soon.

Should I continue to fertilize until they bloom? What do bloom stalks look like?
My gingers are a little crispy fried around the edges, so I think I'll keep them under an umbrella that still lets some sunlight through (sunbrella type material).
Thanks for your help. Sometimes, I think I just need some reassurance.

I grow in Florida which is a lot hotter that San Antonio (I know I used to live in Austin) and we grow all the hedychiums (butterfly gingers) in full sun. I even grow some semi-aquatically in a natural bog and they have been in bloom for 3 weeks. They won't crisp up if you keep them watered well enough, and they need sun to bloom, as well as FOOD. Try weekly Miracle Grow as was suggested, you could even alternate with 10-50-10. Its not too late, my plants start blooming in late June and bloom through September. Right now I have Daniel Weeks, Coronarium, Brandie Sato, Dr Moy, Pink V and Elizabeth in bloom.

Thanks y'all for the advice. I will act on it.

I am the same zone as you and my Gingers bloom Late July but mainly in August. The flower heads well think of a glad but bunch the flower heads together. The flowers are a waxy petaled flower with an incredable scent. Mine prefer a bit of shade in the high noon time but I have grown them in full sun they just require more attention. If this is your first year with them just give them another month and they should perform for you. Gingers at least the common white butterfly ones are rather hardy.

Guess what! Yep, I have a couple of blooms today! I did what was recommended - lots of fertilizer, and water, and took the umbrella away. I'm so happy, because it means I can grow them and with good results. Oh, the fragrance is wonderful. Thanks guys for your tips.