David, I have heard only anecdotal claims that granite grit is to be preferred to lava rock - but I have heard it from more than one grower. I have great success with CA natives in a mix that is 1-1-1-2 decomposed granite, pumice, coarse sand, "potting mix" or various brands. I think adding granite sand to your proposed mix sounds like a good idea. I collect granite from roadsides in the mountains where the free-thaw cycles create a wonderful, especially coarse DG. -|<ipp ________________________________ From: pbs <pbs-bounces@lists.pacificbulbsociety.net> on behalf of D V Andres via pbs <pbs@lists.pacificbulbsociety.net> Sent: Tuesday, October 20, 2020 3:58 PM To: pbs@lists.pacificbulbsociety.net <pbs@lists.pacificbulbsociety.net> Cc: D V Andres <davidvandres@gmail.com> Subject: [pbs] Soil advice Hi, I'm new to growing bulbs from seed. Currently I'm sourcing a cubic yard of soil for a raised garden bed which I'll line with plastic planters and back fill. I'll be growing a few Fritillaria, Calochortus, Iris, species along along with others all native to the the Pacific Northwest. What I'm considering is a 50/50 mix of a seed starting soil from a company called Grab N Grow out of Santa Rosa that contains peat moss, perlite, 1/8″ minus red lava sand, blood meal, bone meal, kelp meal, greensand, dolomite 10, Azomite™, gypsum, oyster shell flour, and soil sulfur and mixing with 3/8'' minus or number 3 sand. The premix soil is pH neutral and sterile and I can buy it in bulk. If I go this option I wonder if I should add granite sand or lava rock sand, etc. My other option is to mix 50/50 3/8'' minus sand with peat moss but I'm not sure if the PH would be ok for seeds. Any suggestions or recommendations would be greatly appreciated Thanks, David Andres Angwin, CA _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>