First of all, we would like to make it clear that jaundice in plants is not actually a disease, but rather a care error. The good news is that you can do something about the problem relatively quickly. If you act in time, the plant will not suffer any long-term damage. Another reason why it's worth checking your garden plants every now and then. So, how do you recognize hydrangea chlorosis, what causes it and what can you do about it?
How do you recognize bleaching addiction?
The problem is relatively easy to identify, regardless of whether it is a panicle hydrangea, farmer's hydrangea or another variety, by looking at the leaves:
- The first symptoms appear on the young leaves
- Hydrangea first gets light green leaves
- soon the leaves turn yellow
- The leaf veins, however, are still green and therefore clearly visible
Notice: Since there are also plant diseases that have similar symptoms, you should first rule them out. If it is not one of the usual diseases, you can take action against chlorosis in the hydrangea.
What is the cause of chlorosis in hydrangea?
So if it is not a disease in the true sense and not caused by viruses, bacteria orcaused by fungithen where do the symptoms come from? Why do the leaves turn yellow?
The reason why the leaves turn yellow is because the plant can no longer produce chlorophyll because its metabolism in relation to photosynthesis is disturbed. In extreme cases it even begins to break it down. Accordingly, the green color disappears. But why is this happening?
The cause is a nutrient deficiency and, more precisely, the plant lacks iron. This happens if you fertilize either too rarely or with the wrong products, i.e. with an inadequate composition. Plants always react differently to nutrient deficiencies, depending on which nutrient they are missing.
What are the consequences of chlorosis in hydrangeas and other plants?
As already mentioned, the metabolism is disturbed. Photosynthesis in plants serves to convert the sun's energy into plant energy. If this process is disrupted, your plant will gradually die after first shedding its leaves. Depending on whether they are vegetable plants or ornamental plants, you will also have a weaker harvest/bloom, if not none at all.
Since this process takes place quite slowly until it finally dies (months to years), you don't have to panic right away, because you have almost all the time in the world to save your hydrangea and will only have to lose out on the blooms this season at most.
What you can do about iron deficiency in plants
It's actually quite obvious: you should of course make sure that you fix the problem. This does not mean anything other than that you should apply iron fertilizer as soon as possible. Suitable are:
- Iron granulate
- Iron liquid fertilizer
- Blattdünger
Foliar fertilizer works fastest, but is rather unnecessary for the hobby gardener as it is expensive and is primarily intended to save large harvests. In private gardens, it is completely sufficient to use normal liquid fertilizer. Special rhododendron fertilizers, for example, are well suited because their composition is tailored to exactly what you need for hydrangeas with iron deficiency. Granules decompose more slowly and would be a good option after applying liquid fertilizer, for example.
Pests common to the hydrangea bushcan be found here.
Important: Why iron fertilizer is sometimes not enough
Have you discovered during a soil test that it is actually not lacking in iron and are now wondering why yellow leaves appear on hydrangeas even though there is no other disease? The reason is quite simply that the nutrient content is not the problem, but rather that the plant is not able to absorb the iron effectively. In this case, the soil composition is not optimal.
That means:
Once the plant has been well cared for, you should also think about a long-term solution to prevent the problem from recurring. How should the soil be composed to avoid chlorosis in hydrangeas in the future?
- sauer
- rich in iron
- peat reduced
In the future, it is also best to use granules for fertilization, which ideally are able to additionally acidify the soil with the help of iron sulfate. In this way, you not only continuously supply the soil with iron, but also create the necessary pH value so that the hydrangea can absorb the nutrient. You should also know the value immediatelycheck annuallyto avoid a new deficiency.
A good home remedy that can, among other things, make the earth more acidic,is coffee grounds.
Worth knowing:
There is the so-called “absolute iron deficiency” and the “relative iron deficiency”. What's the difference?
- Absolute iron deficiencymeans that the iron in the soil is missing or severely lacking and the plant is therefore suffering. If your hydrangea is a potted plant, this type of deficiency is more likely. Otherwise, this absolute deficiency is rare.
- Relative iron deficiencyis what we explained last: iron is in the soil, but cannot be absorbed due to the unfavorable pH value, so this has to be adjusted. This mainly happens in calcareous soils.
Distinguish other nutrient deficiencies
You already know the symptoms of chlorosis in hydrangeas. But to be on the safe side, you should also be aware of other nutrient deficiencies:
- Potassium deficiency – edges of leaves turn brown and eventually wilt; If there is insufficient potassium supply, the plant is more likely to suffer from fungal diseases
- Magnesium deficiency – the same signs as iron deficiency,BUTfirst on the old leaves
- Phosphorus deficiency – leaves become dark green or even reddish
- Nitrogen deficiency – old leaves are affected first, turning yellow; Leaf veins are in this casenotgreen
- Sulfur deficiency – see nitrogen deficiency; occurs very rarely and can initially be ruled out
How pH affects flower colorfind out here.
Cover photo: Sveten/Shutterstock
