Beginner Gardening: Pieris Turning Yellow, 1 by GardeningMommy

GardeningMommy wrote:
My Pieris japonica 'Mountain Fire' has gone from a healthy green and red to a distinct yellow (on the outer leaves--the ones on the inside of the shrub are still green). What could be happening? It's getting regular water through sprinklers, is in full sun, and has had no supplemental fertilizer (just compost in the hole when I planted it in April-ish). Could it be the heat/sun? It's been 90-100 degrees here regularly lately. Oh, and the brown spots on the leaves almost look like burn marks, making me again wonder if it's the heat/sun. What can I do?