I'm not familiar with Promix so can't comment on it one way or the other. Is Miracle Grow potting mix too expensive? You could try that as a base, but you would have to add lots more perlite and other amendments to it. I can't give you an exact recipe or ingredients for your area, just make sure whatever you settle on doesn't clump in your hand when you finish the final blending. Also watch the moisture your daylilies receive over winter. The roots will go dormant and if you add too much water they will just rot. .....Maryl
