I’m just starting to explore the use of akadama. It does sound like an excellent growing medium, from all I’ve heard and read.
But a bonsai professional who lives in a slightly milder climate downstate recently told me that he does not use akadama in the mix for any trees that will spend the winter outdoors in freezing temperatures. His reason: he has found that akadama holds enough water that when it freezes, not being fired, it is reduced to dust. And that does his trees no good. He has switched to a product called calidama for ponderosas, etc.
Has anyone else had similar experience with akadama? Is this its one significant weak point?
(BTW, I checked Ryan’s local climate: per the government websites, St. Helens, OR, does not get lows below freezing in an average year.)