Davevall
Yamadori
Try Frank at Sonlight Nursery. I just bought a beautiful Trident from him. http://www.sonlightnursery.com/SonlightNursery/Welcome.html
Were they bare root seedlings when you received them in December? If so, it is generally best to protect them from freezing the duration of the winter. If they were established in a pot then they would not need protection from freezing. Recently repotted/potted trees are more fragile and susceptible to death due to environmental conditions. Just a thought.Every one of my tridents met their demise as the result of a couple of nights around 23 degrees. I thought that they would be a bit tougher as they were dormant but not so much. *cry* Next year I will start with tridents!
Were they bare root seedlings when you received them in December? If so, it is generally best to protect them from freezing the duration of the winter. If they were established in a pot then they would not need protection from freezing. Recently repotted/potted trees are more fragile and susceptible to death due to environmental conditions. Just a thought.