Gardenia soil -- too basic
So I recently repotted a small gardenia and watered it with Miracle Gro Rhododendron and Azalea mix, but a significant portion of leaves turned yellow. I just tested the soil and its pH was nearly 8! Too basic! How can I get back to the correct pH? I suspect I did not combine the right amount of water and soluble mix in the watering pot. :-(
And should I be using fertilizer in October or should I hold off until the spring?