By Nutrient/Mineral#

pH	Hydrangeas: Pink flowers indicate acid soil; blue flowers indicate alkaline soil; due to anthocyanin content of flowers.
Boron	Toxicity indicated by ChickPeas; symptoms show as a yellowing or dying

of the tips and margins of the leaves, with the older leaves being more severely affected than younger leaves.

Zinc	Deficiency may be indicated by ChickPeas.

By Plant Species#

ChickPeas

ChickPeas are sensitive to Zinc deficiency, so may be an indicator for this. They are also considered sensitive to boron toxicity. Symptoms show as a yellowing or dying

of the tips and margins of the leaves, with the older leaves being more severely affected than younger leaves.