TheRhododendron is an ornamental treewith the most beautiful flowers. If cared for properly, it will delight the eye all spring long with its large, delicate flowers. Above all, it is very important to provide the plant with regular fertilization. The hobby gardener should keep a few things in mind. We explain how to fertilize the rhododendron, which home remedies can be used and how you can improve the soil.
Fertilize rhododendrons: Supply the plants with important nutrients in spring
The rhododendron is usually fertilized in spring. Fertilizing in autumn makes the tree more susceptible to frost, so it is not recommended. March is the right time to improve the soil with suitable fertilizer. Young plants in particular need a lot of nutrients to develop their roots and grow quickly. The rule of thumb applies: You should incorporate long-term fertilizer into the soil in March and liquid fertilizer in April. Depending on your needs and soil composition, you can fertilize the tree a second time in the summer.
However, finding the right fertilizer is not easy. Because the rhododendron is very sensitivereacts to lime, the fertilizer should have a neutral to slightly acidic pH value. Suitable fertilizers include:
- Coffee grounds – fertilize once at the start of the garden season
- Coniferous compost – fertilize every three weeks
- Horn shavings – fertilize the rhododendron every two weeks
- Horse manure – spread on the ground every two weeks
- Blaukorn – use every two to three weeks
- Vinegar – only use when necessary, highly diluted, maximum once a year
Fertilize the rhododendron correctly: horn shavings improve the soil without changing its pH value
The horn shavings are made from the claws and the horns of barks. The horn shavings are mainly rich in nitrogen, but contain very little phosphate, potassium and other useful building materials. If the soil in your garden is humus-rich, you can only fertilize the rhododendron with horn shavings. Simply spread them around the roots, which mostly grow superficially. However, if it is lean, you can add the horn shavings to the fertilizer. For example, compost that contains important nutrients is well suited. Compost made from bark or leaves that is made without adding lime is best.
Fertilizer with iron to combat limescale in the soil: Fertilize the rhododendron with coffee grounds
Coffee grounds offer several advantages over iron fertilizer from the garden center: They are a natural fertilizer and do not contain any harmful substances. It can also lower the pH of the soil and help against limescale in the soil. Since the rhododendron reacts very sensitively to lime and, in the worst case, can even die, you should water the plant with lime-free water and regularly check the soil composition in the laboratory. It's best to do this at the start of the gardening season. Along with the lab results, you will also receive fertilizer recommendations. If these also contain iron fertilizer, you can take coffee grounds and work them directly into the root area.
Fertilizer from horse manure
More matureHorse manure may be the perfect fertilizerfor the rhododendron. It smells significantly less than cow manure and supplies the soil with all the important nutrients. Spread horse manure around the plant every two weeks. You can start doing this in March. You can stop fertilizing in mid-May.
Fertilize rhododendron: Yellow leaves are a sign of iron deficiency
The excessive lime content in the soil prevents the rhododendron from absorbing iron. The deficiency is noticeable through yellow leaves. But what should you do if the rhododendron leaves turn yellow? The first thing you should do is measure the pH of the soil. If it is above 8.5, then only one thing can help: replace the soil. It is best to buy substrate for rhododendron andmix blue grainat. If the pH is between 7 and 8.5, then you can save yourself the laborious and expensive replacement and instead dilute vinegar with water and water the plant with the solution. However, this home remedy kills all microorganisms in the soil that decompose the substances and are very important for the plants. Therefore, you should supply the soil with natural fertilizer in the next few days. Homemade coniferous compost is best.
Vinegar against weeds and pests
By the way, vinegar also helps with pest infestationsagainst weeds. If you have weeds, simply pour the vinegar solution directly onto the plants. After two weeks you can repeat the process. Then you should definitely fertilize the rhododendron.
However, you should only use vinegar if it is highly diluted. Otherwise it could burn the roots of the rhododendron.
