Dec 14, Low levels of magnesium or phosphorous in the soil can cause leaves to turn purplish or red, though typically leaves exhibit yellowing before reaching the red stage.
Mar 23, Reddening of the leaves of blueberry plants can be caused by a lack of phosphorus. Although coffee grounds contain phosphorus, they are also highly acidic. If your blueberry plant were already in acidic soil as it should have been, you could have made it even more acidic rendering phosphorus insoluble and unavailable to the roots.
Phosphorus deficiency causes purple coloration in blueberry leaves, but this is rarely observed in the field. Blueberries have a low P requirement. If the pH is too high (>) for adequate P uptake, other nutrients likely will be unavailable as well. Leaves are red: Reddening is interveinal. Possible causes: Magnesium deficiency. Blueberry is a crown forming, woody, perennial shrub in the family Ericaceae grown for its fruits, or berries, of the same name.
The blueberry plant possesses oval or elliptical leaves which grow alternately on the stems.
The stems, or twigs, are yellow/green in color and turn reddish in winter. Flowers are bell shaped and can be either white or pink, occurring in clusters of 8 to 10 flowers.