International Bonsai Master Walter Pall has an article titled “The cork bark oak catastrophy“. Basically according to Walter the tree suffered a huge set back to an over night frost. The tree was in a greenhouse and still suffered damage. I have one Cork Bark Oak and I take it into the garage when temps get down to 32 F. I once left it out when it was colder it also suffered damage. Learned my lesson the hard way, any sign of cold and into the garage it goes. I have added the article to the Quercus (Oak) Bonsai page, under Deciduous Bonsai and Bonsai Tree Information.

Quercus Suber – Cork Bark Bonsai Courtesy of Walter Pall

Quercus Suber – Cork Bark Bonsai Courtesy of Walter Pall

Quercus Suber – Cork Bark Bonsai Courtesy of Walter Pall