Why is my lemon tree getting yellow leaves? We explain what can cause it and how to get rid of it.
Yellow leaves on the lemon tree (Citrus x limon) are always a clear sign that something is wrong with the nutrient supply or care . The task now is to find and eliminate the cause of this yellowing, also known as chlorosis. Because over time, your lemon tree will gradually shed its leaves and may even die. Nevertheless, yellow leaves or a slight loss of leaves are not a reason to panic at first. Once the cause has been found, the tree can usually be easily cured. Even if your lemon has already lost all its leaves, it can sprout again fresh.
Detect chlorosis in lemon trees
Chlorosis in lemons and other members of the rue family (Rutaceae) usually looks very similar: Due to a lack or breakdown of chlorophyll, the green leaf pigment, the leaves on the lemon tree turn yellow. Sometimes the whole leaf is affected, sometimes only the spaces between the leaves, while the veins remain green. Untreated chlorosis severely weakens the affected plant and in some cases can even lead to the death of the entire plant.
Causes of Yellow Leaves on Lemon Tree
Chlorosis can have various causes. Every now and then some old leaves turn yellow. But if many leaves are affected at the same time, this is a clear warning signal. It can indicate different problems:
- Waterlogging: Frequent watering is well intentioned, but can quickly become too much for the Mediterranean plants. If waterlogging forms, the roots begin to rot and the leaves turn yellow. Check to see if the soil is heavily soaked or there is water in the planter.
- Drought: Long periods of drought can also lead to yellow leaves. The leaves are then often slightly curved. This type of chlorosis is rare on lemon trees.
- Iron deficiency: Various deficiency symptoms of the lemon tree are expressed in leaf chlorosis. Most often occurs on the lemon treeiron deficiency. The still young leaves and shoot tips turn completely yellow to almost white from the edge of the leaf inwards. Lemons have a high iron requirement. Too high or too low a pH value in the soil binds the existing iron and the plant can no longer absorb it. A pH between 5.0 and 7.5 is ideal for the lemon tree.
- Magnesium deficiency: Yellow leaves with green veins are typical of a magnesium deficiency in lemon trees. The yellowing begins first on the old, lower leaves. The leaf veins remain dark green in the middle for a long time and stand out clearly. Acidic soils with a pH below 5 fix the magnesium in the soil. The plant then increasingly suffers from deficiency symptoms because it can no longer absorb the nutrient.
- Lack of nitrogen: If the lemon has not been fertilized or repotted for a long time, the nitrogen may be lacking. Chlorosis begins on the lower, older leaves. After a while, these tend to fall off. The yellowing then slowly spreads upwards towards the young leaves. Deficiencies in other elements - such as zinc or molybdenum - can also cause similar symptoms, but this is very rare.
- Cold: Lemon trees need warmth and their roots quickly suffer from low temperatures in winter. If these sink too much in the winter quarters, yellow leaves form on the lemon. In this so-called winter chlorosis, the leaf veins turn yellow first. A mat or styrofoam plate under the pot protects the roots of the lemon tree from too much cold. The temperature during the winter should be around 3 to 10 °C. Winter chlorosis will resolve itself as the temperature increases.
- Wrong location: An unsuitable location can also lead to yellow leaves and leaf shedding. Drafts or a lack of light may be the causes. Especially in the winter quarters, a combination of too much heat and too little light is often responsible for the discoloration of the leaves and leaf fall. But be careful: changing location too often also causes stress in the plant.
Control and avoid yellow leaves on the lemon tree
Different causes require different measures - but how do you tackle the causes of chlorosis in lemon trees?
- In case of waterlogging the first thing to do is to water less. Especially in the coldWinter quarters, when the plant hardly evaporates any water, it should only be watered extremely sparingly. To prevent waterlogging, permeable soil, a drainage layer and good drainage in the pot are helpful. However, repotting the plant as an immediate measure only makes sense in spring at the beginning of the new vegetation period, as plant growth is stimulated by repotting.
- In case of drought the plant should be sufficiently watered, especially during the growing season in the warm months. But first make sure that dryness is really the trigger for the yellow leaves. Oftentimes, well-intentioned watering will only damage already weakened lemon trees when drought is not the actual cause.
- If there is a lack of nutrients the correct fertilization of the lemon tree is crucial. Many nutrient deficiencies can be remedied quickly and effectively with the help of a primarily organic liquid fertilizer, such as our Plantura Organic Citrus & Mediterranean Fertilizer. In addition to the main nutrients nitrogen and potassium, iron is also included in addition to other minerals, so that the liquid fertilizer can also be used against iron deficiency symptoms. However, keep in mind that even if there are signs of deficiency, you should no longer fertilize from August until next spring. Regular repotting of the lemon is a preventive measure against nutrient deficiency.
Tip: Additional magnesium deficiencies can be remedied by spraying the leaves with a special magnesium fertilizer. Adjusting the pH value, for example by repotting in suitable soil or lightly liming, is usually sufficient.
- In case of a wrong location you should of course find a new place for your lemon tree. The lemon prefers sunny, warm and sheltered locations. Cold drafts, on the other hand, can damage the lemon tree. Therefore, think carefully about whether the planned location is really suitable, because a change of location also brings new stress with it.
Preventing chlorosis on the lemon tree
The cause of iron deficiency and the associated chlorosis often lies in the soil. The soil of purchased potted plants is usually of poor quality and the plant should therefore be repotted to prevent chlorosis. For repotting, we recommend high-quality, loose soil with an optimal pH of around 5.5 to 6.5. It does not necessarily have to be a special citrus soil. Suitable potting soil can be sand, bentonite or othersloosening materials and can thus be mixed by yourself.
It is much more important that as much of the old soil as possible is removed when repotting without damaging the roots. Alternatively, you can determine the pH of the soil, for example with a pH measuring set. If the pH value is actually too high or too low, it can be lowered with a little Epsom s alt or carefully raised with a light addition of lime.
Note: Citrus plants in general only require small amounts of the plant nutrient element phosphate. It is therefore practical to use phosphate-reduced citrus fertilizers such as our Plantura Organic Citrus & Mediteranean Fertilizer, because this not only meets the needs of the beloved lemon, but also saves finite resources.
Yellow leaves and leaf fall are often accompanied by a failure to flower. In our special article you will find out why this is so and what other reasons it can have that your lemon tree is not blooming.
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