It may be your water quality. Stromanthe and Maranta are very sensitive to things like fluoride and chlorine in the water.

You might try buying pure water or using R/O water and see if it makes a difference.

I grow the variegated tri-color stromanthe and another all green one that gets red flowers out in my yard as "die back" perennials here. They can take temps in the high 20's fine but will die back to the roots in the lower 20's, but they do come back, so I would think you might be able to prune it back and let the new growth flush out again, especially now that its summer.

Hey gardenlady,
Yes they burn like crazy!! And they can get very crispy down her in Fl., the very shaded ones not so bad if watered really really well. Tell ya what we do,(it's so simple yet rarely though of) just trim off all the dry or brown areas with a pare of sisors(!!) even reshaping to leaf till it looks just like new only smaller...it works.
It is better than cutting off the whole leaf if just the ends are burnt, we do it all the time with all our tropical
plants, they all seem to burn a bit in the HOT and Dry months. Also good for triming of the little frost bites we get. Now we do have on Stromanthea tucked way back in the shade along side our ponds waterfall that i'm sure gets lots of srip and overflow water...that one seem to burn much much less. I think I'll try on in the ponds edge or in the falls to see if keeping there feet wet solves the burning problems and to see if they can take having there feet wet all the time, we'll see. Well, here's a few pic's of the one back by the falls and a few of one of the other Stro's flowering. Happy Gardening, Terry.http://picasaweb.google.com/terfran/BackUpCopyMovedFromFrancesSComputer/photo#5204632100972689746
this one's a little bright.http://picasaweb.google.com/terfran/GardenPics41908/photo#5194466219742334514

Hmmm, no picture...

rose, what a beautiful photo. Thanks for sharing that!
I recieved the tricolor stomanthe from a great friend. It likes bright indirect light and to stay a little on the damp side. It seems to like rainwater.

Thank you Rose...I'm going to try your suggestion on just trimming the dead off with a scissors! I like that idea better.
Love your picture too....