Which nutrient is the flower lacking? You can tell by looking at the leaves

Telling which nutrient a flower is lacking by its leaves:

① If symptoms first appear on old leaves, the plant is lacking chlorine, phosphorus, potassium, magnesium, zinc, etc. If symptoms first appear on new growth, the plant is lacking calcium, iron, boron, etc.

② When fluorine is deficient, the whole plant turns dark green, the leaf stalks turn purple, growth is stunted, the old leaves have no spots but yellowing appears between the veins, and the leaves drop easily.

③ When potassium or zinc is deficient, yellow, brown and purple spots appear on the old leaves (varying by flower), the leaf tips scorch and curl downward, the leaves turn yellow from the edges toward the center while the veins remain green, the leaf margins curl upward or downward, and the leaves gradually wither.

④ When boron or calcium is deficient, symptoms begin on the new leaves and can easily cause the terminal bud to die.

⑤ When iron is deficient, the young leaves appear yellow-white, the veins remain green, but over time the leaf margins gradually wither.