I was lucky enough to go to Kew Gardens in the summer of 2009. I was just getting into bamboo at the time and I didn't really appreciate their bamboo specimens as much as I would today.
I still took some pictures and saw a few bamboo I knew I wanted to try. Fargesia denudata was a nice looking bamboo.
Imagine my surprise when I actually sourced one at a garden center off the highway in Nova Scotia. Bamboo are extremely rare on the East coast of Canada. Home Depot sold some Fargesia species (tissue culture) for a couple years and that's about it. The plant tag said zone 5 but I knew better. The books I had rated it hardy to -22 degrres Celsius or so. I knew it would probably defoliate in the winter.
Summer 2010
I really started to question the hardiness when I noticed leaves browning up shortly after temperatures just below zero. Considering its age and how little time it had to establish itself, I thought maybe those factors and the site location (fairly dry) may have contributed to its poor hardiness. Time will tell with bamboo.
Spring 2011
Obviously it was totally fried after the winter. I didn't have much hope, but it shot up new culms in the Spring and leafed out nicely. I would say a little smaller in size than the original planting. I thought that after a full season to get established, it may improve its hardiness.
Summer 2011
Winter 2011 - after temps of negative 17 degrees Celsius. Total culm death again. We will see what happens next Spring.
In general Fargesia species have done quite poorly so far. They are painfully slow to upsize and shoot very late in the season. EXCEPT for rufa. Fargesia rufa has done extremely well, holding up to temperatures beyond its hardiness rating.
Only time will tell if denudata, murielae or nitida will finally get going and upsize.
TC