Status: 04/02/2023 05:00 a.m
Which fertilizer is particularly suitable for rhododendrons? And when is the best time to fertilize? To ensure that the plant blooms profusely in spring, you should pay attention to a few things.
A healthy rhododendron can be recognized by its lush green leaves and colorful flowers, which appear between April and May, depending on the variety. So that the plant gets enough nutrients, it must be fertilized regularly and should be in loose, lime-free soil grow garden soil.
Fertilize rhododendrons in spring and summer
Horn shavings are often used in the garden as an organic long-term fertilizer.
Rhododendrons are usually fertilized once or twice a year. The ideal time for this is in spring before flowering and again with half the amount at the end of June to mid-July. If rhododendrons are planted fresh in spring, they should first take root well before they receive additional nutrients for the first time after about two to three weeks. If you plant it in autumn, the first fertilization should take place regularly in spring.
A mixture consisting of equal parts of horn semolina or horn shavings (organic fertilizer) and a complete fertilizer. A bush of one meter in height and width needs about 100 grams of the mentioned mixture for spring fertilization. Small-leaved rhododendrons get by with half the amount of nutrients. There are also special fertilizers for rhododendrons that are precisely tailored to the needs of the plant.
Rhododendron is sensitive to lime
Rhododendrons are sensitive to excessive lime content in the soil. They belong to the moor bed plants and prefer a pH value of 4.5 to 6. The easiest way to achieve this is with a special soil or a peat-soil mixture in a ratio of 1:1. If the pH of the soil is too high, the rhododendron can only poorly absorb the nutrients in the soil. It is therefore recommended to avoid calcareous tap water when watering and instead to use use rainwater.
Additionally, adding coffee grounds can help improve the soil. However, coffee grounds are not a substitute for fertilizing as they contain only a small amount of nutrients. Using household vinegar can also help improve the soil and make the soil more acidic. For this purpose, it is essential to check the pH value of the soil in advance using a commercially available test kit. Always use vinegar carefully: add one to two tablespoons of vinegar to three liters of water. Repeat the procedure at most every three months.
Yellow leaves are a sign of nutrient deficiency
Yellow discoloration on the leaves indicates a nutrient deficiency.
Yellow leaves on rhododendrons are usually a sign of nutrient deficiency. If the leaves are consistently yellow, the plant often lacks nitrogen or magnesium. If the leaves also have a green bone pattern, iron is missing. A special rhododendron fertilizer from specialist shops supplies the plant with the missing nutrients in the short term. In the case of an acute magnesium deficiency, the addition of Epsom salt (magnesium sulfate) can also help. Either work this directly into the soil or dissolve it in the irrigation water.
Possible nitrogen deficiency due to mulch layer
If the soil around the rhododendron been mulched, it is essential to carefully remove the mulch layer before fertilizing. Mulch prevents rhododendrons from receiving all of the nutrients supplied. Bark mulch often causes a nitrogen deficiency in plants.
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