Blueberry leaves turning red.
I have a two-year-old planting of four types of blueberries containing 750 plants. All of a sudden in the last few days the leaves on all plants have turned red. New growth starts out green and healthy-looking but the leaves begin turning right away. I've been amending the sandy soil with sulfur for several years, the last time being last fall at the rate of about 550 lbs. per acre. The soil pH had edged up near 6.0 from around 5.2 when I planted two years ago. This spring each plant received 4 oz. of ammonium sulfate applied through bark mulch at bud formation and I plan to apply the same amount again in a week or so. Our weather has been all over the map from hot and dry to freezing (frost last two nights) and the berries are just now blossoming. I'm at my wit's end and need some advice as to how to proceed. Thanks
The red color is just the leaves response to the cool weather we are having.
The red coloration will go away when the temperatures warm back up.
I have seen this many times and it is nothing to worry about.