Pumice, expanded shale, or turface for hot climates?
I live in Texas with crazy hot, long summers and plan on growing 10 blueberry plants and 6 raspberry plants in Fabric pots. I am worried about the pots drying out incredibly fast even if I water every day and then running into the issues associated with rehydrating a mixture of pine bark, peat moss, and perlite.
So I was considering replacing the perlite with either turface, pumice, or expanded shale if I can find it in less than 3/8" size. I've read if you go higher than a 8:1 ratio of pine bark to turface then growth is impeded and that Turface is also very difficult to rehydrate.
Recommendations for increasing moisture retention?