My Gardenia is very young (received in fall of 2011) and has few new leaves coming out. Some of the leaves are green but others are yellowing and turning brown tipped. I have my plant in a small container outside in full sun. We have had 31/2 inches of rain in the last couple days and I water my plants every Monday. I water with Miracle Grow 1x month. The temps are fluctuating weekly here 40-70 eve's. /early am to 55 to 80 afternoon/day.