I'm sorry, the "5:1:1 mix" was referring to 5 parts pine, 1 part perlite, 1 part humus / worm castings.
The ferilizer changes throughout the year. But it's mostly 4-3-6, with some 5-1-4 in early spring, and some chelates, when I feel the plant needs them.
At first they stay green (even the fallen ones). But as the tree keeps declining, some will turn brown along the edges, in an inverted v-shape, starting from the tip.
Temperature stress is something I'll have to look into. Thank you!