I used to grow my Fargesia in an area receiving noon and pm sun (to create a screen). They were not happy so I moved them to dappled AM sun--big difference. Fargesia and other mountain bamboos have a bit of an issue with high heat (especially at night)--one reason they have problems in the southeast. It has just been too hot to the liking of these mountain bamboo and your exposure sounds hot. You may have to go with a differ plant screen in the current area and relocate the Fargesia to a shadier/cooler locale. In the area that I originally had the bamboo in, I decided to put in a fence and then establised a hedge of boxwood. Good luck!

I concur with the points njoasis makes. The only other thing I can suggest is plenty of water. It's hard to over-water bamboo. Once a day in your weather may be the MINIMUM you should do....

Thanks njoasis and kudzu9. Since sun may be
the culprit and/or underwatering, I will follow
your advice. Any suggestions for a clumping,sun tolerant
variety thats hardy to zone 6?

Sometimes it takes a while for newly planted bamboo to settle in and get established, especially in hot weather. They may perk up yet if you keep them watered. However, I am a little concerned about winter since you are at the limits of hardiness for robusta in Zone 6. If these bamboo don't work out for you, you could try a hardier clumper like Fargesia nitida or one of its cultivars.

It's hard to over-water bamboo unless there is poor drainage and the soil stays soggy. Especially with a new small plant. Does under-watering result in yellow culms?

When new shoots get yellowish, they usually have stopped growing and have died for whatever reason. When mature culms change from green to yellow, it may just be due to sun exposure. However, when a mature culm becomes tan and the surface is "flat-looking," it is either dying or getting toward the end of its expected life.

I have tried growing various fargesias here in SE Michigan and the problem has always been summer heat. The only one I have had success with is Fargesia 'Rufa' - after 2 years in the ground, my Rufas have been growing like crazy here with some fertilizer and a little water, and they don't seem to mind the heat at all.