Over the last few days my croton has dropped about 5 leaves between the two TOP stems. None from the bottom. It is in Miracle Grow potting soil. I purchased it from Walmart about 2.5 months ago. It was repotted after two weeks of taking it home. I mist it twice a week, and water when the soil begins to feel dry. It is in an eastern-facing window, and gets about 1.5-2 hours of fairly direct sunlight each day. It also has no bugs. Since the weather is getting colder, could that be it? I'm also thinking maybe it isn't getting enough water. Since overwatering usually causes the lower leaves to drop/die, I would assume maybe water isn't making it all the way to the top of my plant. I'm new to growing, and it's one of 10 other plants I have growing in the house. I also have baby tomato and lemon trees in the same window. All look fine. Any help? I don't want it to die!