Yellow leaves on grapevines indicate iron deficiency. Plants often suffer from what is known as chlorosis due to an incorrect pH value.
If vines develop yellow leaves although autumn is far from in sight, this is called chlorosis. The plant disease, also known as chlorosis, can even lead to the death of the entire vine plant over a long period of time. In the case of chlorosis, green chlorophyll is no longer produced in the leaves. Without this dye, however, the plant cannot carry out photosynthesis. So that the plant still produces a rich harvest, you should definitely treat the chlorosis.
Detecting chlorosis on grapevines
In wine, jaundice is usually caused by a lack of the important nutrient iron. Such a deficiency can also occur when there are actually enough iron reserves in the soil. But more on that later. In the case of vines, it is often the young leaves that turn yellow first, with the leaf veins initially remaining green. Tendrils, young shoots and grapes can also be affected. If chlorosis spreads, it's only a matter of time before the leaves fall off. Incidentally, magnesium deficiency chlorosis with similar symptoms can also occur in white wine varieties.
Grapevines: prevent chlorosis
As already mentioned, in most cases an iron deficiency is responsible for the chlorosis. This is triggered by drought, waterlogging, compacted soil and especially by a too high pH value. In all cases, the wine cannot absorb enough iron, although there is actually enough in the soil. If the drought persists, it must be watered occasionally. Green manure or compost can help against compacted soil and waterlogging. The humus in the compost allows water to drain off better and ensures a better soil structure. If none of this helps, then it is worth taking a look at the soil pH value. This is fairly easy to measure with an easy-to-use test. For light soil the pH should not be above 6.3 and for heavy soil the limit is around 7. Most soils will not exceed these pH levels.If yours does, you can adjust the pH down with Epsom s alts or lime-free peat.
Chlorosis and chlorosis of grapevines: treat and fight
If all preventive measures have not helped, then there may really be a real nutrient deficiency of iron or magnesium. In order to remedy this particularly quickly, foliar fertilization is a good idea. Since the fertilizer must not be too highly concentrated here, a special foliar fertilizer should be used. In general, you should pay attention to a balanced and regular fertilization of your wine. It doesn't even have to be a special wine fertilizer: a good fruit fertilizer or organic fertilizer will also do. In the event of an acute deficiency, we recommend our Plantura organic tomato & vegetable fertilizer. The liquid fertilizer is characterized by its rapid effectiveness. If you want to prevent chlorosis, you can use our Plantura organic hydrangea fertilizer. This contains iron and has a three-month long-term effect.
In addition to chlorosis on grapes, powdery mildew is also a problem that many hobby gardeners struggle with. In our special article you will learn how to identify, combat and prevent downy and powdery mildew on wine.