Answer: The results you described are consistent with a winter hardiness problem. Miscanthus sinensis 'Variegatus' is considered hardy into zone 5. Your zip code places you in zone 5A, the coldest part of the zone. However it is possible that if your microclimate is a cold one (windy or exposed, rural and open) then you are actually gardening in a zone 4 situation. Plants set out in the fall are somewhat more subject to winter damage than those planted in the spring, so this may not be representative of their performance over time. I would suggest you mulch around them (not over top of them) in late fall and wait until early spring to trim them back. Fertilize them in early spring and make sure they are well watered. This, plus an extra year in the ground to become better established, may help them get through the winter and recover a bit better. If not, you may want to try a different, more winter hardy plant instead. I'm sorry these are not doing so well for you.
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