This disease is not caused by a pathogen, but by nutritional deficiencies of the plant, in particular it occurs when the plant is not able to perform the photosynthesis of chlorophyll due to the lack or absent assimilation of iron and microelements from the soil.
This may be due to an excess of limestone in the soil, due to a lack of iron, potassium, zinc or nitrogen.
The symptoms consist of a progressive yellowing of the leaves, whose ribs remain of a darker color, and of the deterioration of the plant, which often fails to bloom and produce fruit, and which nevertheless grows in a stunted manner.
It is useful to intervene, even promptly, by administering iron chelated to the plant, so as to favor the absorption of this micro-element by the plants; afterwards it is advisable to keep the soil well ventilated and rich in organic substance in order to avoid any recurrence of chlorosis.
The plants most often affected by chlorosis ferric are: azalea, quince, strawberry, wisteria, raspberry, lauroceraso, hydrangea, peach, rhododendron, rose. In the case of plants, such as the azalea, rhododendron or hydrangea, which love particularly acid soils, it is advisable to use a soil of this type both in the garden, burying it in the hole before planting the plant, and in pots; in this way, and with appropriate fertilizers based on specific fertilizers for acidophilic plants, we will avoid the appearance of chlorosis ferric.
In the event that our plants have already been affected by chlorosis it is appropriate to add so-called greening fertilizers to the irrigation water, which will give the soil the microelements it lacks.