Hi Michael,
Your plants look wonderful!!
Was there a reason you went with Fertilome Ultimate Potting Mix? In reading the Spec Sheet at their site, it lists Sphagnum Peat Moss as between 83 to 93% of its composition. Coarse Perlite, Dolomitic and Calcitic Limestone make up the balance. This seems similar to Pro-Mix BX as well as the "original" Sunshine Mix #4.
Just curious as I am searching to replace the Sunshine
Advanced Mix #4 in my InnTainers this Winter, and was leaning toward a Pro-Mix BX (or HP) formulation. The Sunshine Advanced coir based product ran too wet for my liking this Summer.
Raybo