I thought it might be interesting to gather some information about what the pros use: Tobias Spanner, the owner of Palme Per Paket, published the book "Das Palmen-Kulturhandbuch" 1999. He recommends these soil mixes: 30% {60%} Peat based soil mix or limed peat (pH 6) or coconut substrate (e g "Kokohum") 20% {10%} fine lime-free clay soil or loam 25% {15%} quartz sand 0-4mm 25% {15%} other mineral for drainage: pumice, perlite, vermiculite, LECA, Lavalit (crushed l