On 11 May 2010, at 14:51, Justin Smith wrote: > I read that a mix of leaf mold/sand/yellow lava was good. Not sure what yellow > lava is but pumice I am sure would be ok. Sounds like one of the varieties of pumice distinguished by Japanese bonsai growers. Try googling "bonsai pumice" and you should find plenty of leads that will, if you burrow deeply enough, tell you all about this mysterious substance. You may be able to buy it in small bags from bonsai supply houses, as it's imported from Japan, but you would need to know the "usual" name in order to get the right kind. -- Rodger Whitlock Victoria, British Columbia, Canada Maritime Zone 8, a cool Mediterranean climate on beautiful Vancouver Island http://maps.google.ca/maps/…