A couple of weeks ago I bought a small mugho pine intending to keep it
in a pot on my deck. I potted it with Miracle Gro potting soil, and it
has been steadily turning brown ever since. It's on a south-facing
deck, along with my container garden, and gets plenty of sun and
regular watering. Today I got some Miracle Gro for azaleas and other
acid-loving plants on the hunch that maybe the potting soil wasn't
acidic enough.

Any other ideas?