Also, if you grow them in shade this usually means they're close to some trees, which might have roots competing underground for water and nutrients. Gingers like LOTS of water, so you might need to water them extra in the shade, and give them a really rich top-dressing of compost c/w fert once in a while. (if you put it on top, the tree roots won't gobble all the goodies before the gingers have a chance) I had a clump fairly close to my mango tree for years, and I've gradually had to divide it and move it out because the mango gives too dense shade in summer, and also has out-competed them for water so they pretty much stopped blooming.
Still made nice foliage, though. They're strong plants, if you give them what they need!
