Blueberries develop a maroon color in autumn, but this is normal. They also can develop a reddish-purplish hue in spring if the weather is cold. This coloration disappears during warm weather.
Phosphorus deficiency causes purple coloration in blueberry leaves, but this is rarely observed in the field. Blueberries have a low P requirement, and if the pH is too high for adequate P uptake, other nutrients likely will be unavailable as well.
Back to Blueberry Diagnostic Tool
This is a part of The Berry Diagnostic Tool - a companion to the NRAES Production Guides for Strawberries, Raspberries and Blueberries