I run about 60/40 on my maple mix. I use a little more organic because our summers are very hot and arid. I start with a premium blend of potting soil and add in some inorganic to even the mix. Pumice, lava rock, chicken grit, perlite all are used as is turface.*
Maples are not that picky about soils and do well in a wide range of subtrates. Watering habit is more important. Acers resent changes. If you keep yours on the wet side, don't let them dry out. If you keep on the drier side don't flood them periodicly. Whether it's wetter or drier try to maintain a consistant moisture content. In my arid summer climate I tend to keep mine a little wet because they are very wet during our winter months.
*I am not using the turface in my repots. It has worked well, but I don't like the way it behaves in the pots. It doesn't play well with others. Lava rock, pumice, perlite all have rough surfaces and tend to cling to and hold the organics in place. The smoothe surface of turface does not adhere to the organic matter and I see the turface staying in place and the oraganics washing out to the sides. I have to keep turning it back in.
All in all, I'm not real happy with the performance. It was nice to get 50lb sacks and not have to crawl around gathering pumice and lava, but I think I'll go back to the jungle on this one. Sincerly, Rick
