Late last Summer, 2009, we bought over 35 bamboo plants from MidAtlantic. They are great people and very honest. We got all of our plants in the ground by the end of September. This past winter was the heaviest snowfalls we had experienced in almost 10 years. We did not lose a plant and they all are very healthy. They gave us tips on building our barrier and prunning twice a year. We had to stake some of the new growth because of the high winds. I highly recommend a visit to their groves if possible. Their prices are fair and they select the hardiest plants to send home with you. Now it's my job to manage our investment.
Last year (long before I ever found out about Dave's Garden), I purchased 3 different bamboos from them. Namely Phyllostacys atrovaginata, P. rubromarginata, and Semiarundinaria fastuosa.
All bamboos survived subzero winter temps in my area (as advertised on their site), with only light damage to the leaves, except for the Semiarundinaria fastuosa, which suffered 75% leaf loss but is already sprouting new leaves and sending up at least one new shoot.
Since their nursery is more or less along the route which I traveled when I went to visit one of my friends in Greenville, SC, I just called my orders in and picked the plants up in person, which saved me the shipping costs. On top of that, I got to see their bamboo growing operation first-hand, and I must say that I was totally impressed with the amount and varieties of field-grown bamboo they had on their farm! No tissue cultured or greenhouse-raised stuff from these guys! All their bamboo is grown outdoors, so you can rely on their claims of which bamboos are hardy to zone 7a. I, and a few of the more northerly gardeners (in zones 6 and above) have been giving them feedback on how bamboos we ordered from them fare with our colder temps, which they can then use to update their bamboo hardiness evaluations.
All-in-all top-notch bamboo company, with great plants and books on bamboo and other bamboo-related products (including the all-important rhizome barrier for those who want to grow running bamboos in suburbia).
I've purchased one plant, a phylostachys Aureosulcata Spectabilis, from Mid Atlantic. It was healthy and met their description and my expectations. Service was prompt and they were very helpful. I plan on buying more bamboo from them.