Perlite particle size for 5-1-1
Hello All. As you know I use the 5-1-1 mix for growing conifers and maples in nursery containers. Up to this point I've been using Manna Pro granite instead of perlite in my soil mixes since I had a bunch of granite on hand and wanted to use it up. I'm nearly out of granite now and will switch back to perlite for future soil mixes.
When making the 5-1-1 should I use the coarse (large) grade of perlite? I have a small bag of MG perlite on hand but I think the particle size is "medium" at best, mostly 1/4" and smaller.
I have not found any coarse grades of perlite locally so I might have to use mail order.