Fertilizing lemon tree: when, how & with what is the right fertilizer?
The yellow fruits of the lemon tree bring a Mediterranean flair to our gardens. When, how and with what to fertilize the lemon tree correctly, you can find out here.
The lemon should be fertilized regularly during the growth period as well as during flowering and fruiting [Photo: Frank Gaertner / Shutterstock.com]
The lemon tree ( Citrus x limon ) with its bright yellow fruits is one of the most popular citrus plants among the diamond plants (Rutaceae). Due to its sensitivity to cold, the lemon tree is almost exclusively cultivated in planters in our latitudes. The supply of nutrients in the planter is limited, which is why the lemon tree needs additional fertilization in addition to fresh soil if it is repotted regularly. But which fertilizer is suitable for lemons? When and how often should the lemon tree be fertilized? We have summarized the answers to these questions for you in the following article.
When to fertilize a lemon tree
The lemon tree is only fertilized in the growth phase, because in this phase the nutrients are well absorbed and metabolized. The growth of the lemon depends mainly on the temperature and the light conditions. The first fertilization takes place between April and May for shoot growth and new shoots of the young leaves. If the lemon tree is repotted and given fresh potting soil, it does not have to be fertilized for the first time until a few weeks later. You can find out details about this in our article on the timing and procedure for repotting the lemon tree. In the summer months, fertilization should also be carried out regularly during flowering and fruiting. As soon as the lemon tree stops growing in autumn, you should no longer fertilize, because the plants hardly take up any more nutrients from the soil at low temperatures. Over-fertilizing the substrate during the resting phase in winter should be avoided in order to protect the roots.
Summary: when should you fertilize the lemon tree?
- First fertilization at the beginning of leaf shoots from April.
- If the pots are repotted, fertilization is only necessary a few weeks later.
- Re-fertilize regularly during the growing season up to October.
Recognize deficiency symptoms in the lemon tree
A nutrient deficiency is likely if you have not or only rarely fertilized your lemon tree and have not repotted it for a long time. The most common deficiency in citrus plants is chlorosis of young leaves due to an iron deficiency. The leaf veins usually remain green. In the case of acute deficiency, iron fertilizers are most effectively administered via foliar fertilization. You can find more information on the procedure and suitable products for iron fertilization in our special article.
A yellow coloration of the lemon tree leaves is often due to a lack of nutrients such as nitrogen, magnesium or iron [Photo: Gengis90 / Shutterstock.com]
In addition to iron, deficiencies in nitrogen, magnesium and other nutrients can also be responsible for the yellow coloration. It is therefore all the more important to fertilize as required, which can prevent such a deficiency. The reasons for the deficiency can, however, also lie elsewhere. In our article on the topic of yellow leaves on the lemon tree, we go into the various causes of chlorosis and give tips so that your lemon shines in a lush green again.
Tip: Lime-containing tap water for watering lemon trees can increase the pH value in the soil and thus, for example, inhibit iron absorption. It is therefore best to water your citrus plant with rainwater or stale water and leave the lime that has settled on the ground behind. Together with optimal fertilization, deficiency symptoms – such as chlorosis – can be avoided in this way.
Fertilizing lemon tree: how and with what?
When fertilizing lemon trees, the most important thing is the right combination of nutrients. The plant mainly needs nitrogen (N) for growth, small amounts of phosphate (P) for flower formation and potassium (K) for fruit formation and plant health. The ideal fertilizer should contain a comparably high proportion of nitrogen and potassium. The required amount of phosphate is usually already present in the soil; in fertilizers it should be contained in significantly smaller amounts than N and K. A suitable fertilizer for lemons is also characterized by the addition of micronutrients such as boron (B), manganese (Mn) and iron (Fe).
Organically fertilize lemon tree: instructions
More and more garden fans are relying on organic agents when choosing fertilizers. The use of these near-natural, natural fertilizers for lemon trees offers many advantages, for example:
- Gentle mode of action without danger to soil organisms or over-fertilization.
- Activation and promotion of the microorganisms in the soil.
- Environmentally friendly and resource-friendly by dispensing with chemical synthesis compared to mineral fertilizers.
Our mainly organic Plantura organic citrus & Mediterranean fertilizer fulfills all of these criteria and is ideal for fertilizing your lemon tree. The production from completely animal-free residues from the food, luxury and animal feed industries uses existing resources. In addition, the liquid fertilizer for lemon trees, olives and the like comes to you in a mostly recycled bottle. Of course, optimal fertilization not only depends on the ideal composition, but also on the right amount of nutrients. The primarily organic liquid fertilizer can be used during the lemon growth phase from April to October. Depending on the size and needs of the plant, the fertilizer should be added to the irrigation water and applied every week to every two weeks. 15 to 25 ml of the liquid fertilizer are required for 5 liters of water.
Fertilize lemon tree minerally
In addition to organic fertilizers, there is also a large selection of mineral fertilizers available. In these artificial fertilizers, the nutrients are in water-soluble pure form and can be absorbed directly by the plant. The use of blue grain and Co. does provide a quick nutrient boost, but it also has some disadvantages. Mineral fertilizers cause the salt concentration in the substrate or soil to rise rapidly. Sensitive plants take damage to the roots and can die. If mineral fertilizers are washed out into the deeper soil layers by downpours faster than absorbed by the plants, they can lead to increased nitrate pollution in the groundwater there. The high energy consumption for the production and the often environmentally harmful extraction of raw materials also do not speak in favor of the use of artificial fertilizers.
Mineral fertilizers work quickly, but also have many disadvantages for plants and the environment [Photo: AUKARAWATCYBER / Shutterstock.com]
Fertilize the lemon tree with coffee grounds and the like
If you prefer to use near-natural fertilizers in your garden, there are also various options here. A floor life in the bucket is only available to a limited extent. Therefore, the products should be well matured and the nutrients should be available for plants. Ripe compost or a plant stock made from nettle can be easily made yourself and can make an important contribution to the fertilization of your lemon tree. Nettle liquid manure and other Pflanzensude often contain numerous minerals and can undiluted and annoying pests like aphids (Aphidoidea) away.
Another popular natural fertilizer is a waste product in many households almost every day: Fertilizing with dried coffee grounds above all brings a lot of nitrogen and phosphate into the soil. It can be sprinkled on the ground or added to the irrigation water. Due to its high acid content, coffee grounds should only rarely be used in the lemon tree – i.e. once or twice a year – in low doses.
When the temperatures drop in autumn, it's time to think about hibernating the lemon tree. We will give you tips on which quarters are suitable and how to care for the citrus plant in winter.