Brown Leaves on Blueberry Bush
I planted this blueberry bush about a month ago, using half potting soil and half peat moss. It first started to turn brown when we were having a pretty bad heat week, after several very mild weeks. I started watering it more, and put about 2 to 3 inches of mulch down. Since I've taken the pictures (right after I mulched them), it's gotten browner and more leaves have fallen off. The blueberry bush right next to it, however, hasn't turned brown, at all. It is either a reka vaccinum cory or a duke early vaccinum cory. It is dying, or this just normal fall browning?
Your blueberries are stressed. The foliage in the fall turns a beautiful reddish color not brown. Blueberries have a shallow root system and are devoid of root hairs. This makes them very sensitive to changing water and soil conditions. Mulch should be thin in the containers. In containers you will have to pay attention to watering and may require watering every day depending upon hot summer temperatures and the soil conditions. In small containers the roots can heat up and they can be affected. The plants will also need winter protection because the roots will be susceptible to freezing temperatures.
You will have to make some decisions. Blueberries grow best in the ground. If you have a location to plant them, you may want to do this now. Blueberries like an acidic soil high in organic matter, attention to moisture, and mulch.
If you do not plant in the ground, you should transplant into larger containers about 5 gallons. Make sure the containers have good drainage. See our fruit profile on blueberries http://extension.umd.edu/growit/fruit-profiles/blueberries