Fertilizing rhododendrons: tips on fertilizer & timing

In order for the rhododendron to fully develop its flowers, it needs the right nutrients. We give you tips on how to properly fertilize the rhododendron.

Of the rhododendron (rhododendron) is a shrub genus from the heather family (Ericaceaea). The genus grows in nature primarily on acidic sites with a very permeable subsoil. And fertilization should also be adapted to these special conditions. We'll tell you how you can create the perfect conditions in the home garden and which fertilizers are particularly suitable for your rhododendron.

Rhododendrons are adapted to an acidic, humus-rich and well-drained subsoil. Symptoms of deficiency are very often observed in them, especially yellow leaves. In very many cases, this is due to a lack of nutrients: a lack of nitrogen, iron or magnesium can lead to yellow foliage on rhododendrons. In order to remedy this, it is not always enough to just distribute iron fertilizer for rhododendrons, because that too

Soil pHin which the plant grows must be taken into account. If the value is above 5, i.e. if it is no longer nicely acidic, the acid-loving plant is less able to absorb iron efficiently - even if there is sufficient iron in the soil. That is why it is particularly relevant when Plants of the rhododendron to ensure the acidification of the soil directly.
If the soil is acidic enough, you can fertilize your rhododendron to make it very special shines - in the following we explain the important questions about fertilizing the popular Bushes.

When should you fertilize rhododendrons?

Most rhododendrons need to be fertilized once a year, but it is important when the rhododendrons are fertilized. An organic slow release fertilizer like ours is also best suited for this Plantura organic flower fertilizerthat releases its nutrients over a long period of time. The best time to fertilize is late spring between mid-April and mid-May. A rhododendron should then no longer be fertilized later than mid-June in order not to endanger the hardiness of frost. If you want particularly lush growth, you can also apply two fertilizations at the beginning and at the end of early summer, but one fertilization is sufficient for the health of the shrub. In the case of special weather conditions or unfavorable site conditions, a second fertilization in early summer can also make sense. You should especially consider this after the rainy spring months. Then it may be that the nutrients have already been washed out and the soil is depleted.

Summary: when should you fertilize rhododendrons?

• A stock fertilization per year with a mainly organic long-term fertilizer is sufficient.
• The ideal time is between April and May.
• A second fertilization can be done in early summer.
• After mid-June fertilization no longer makes sense.

The right fertilizer for rhododendrons

Bog bed plants such as the rhododendron have shallow roots and love moderately nutrient-rich, humus-rich and well-drained soils with an acidic pH value between 5 and 6. That's because rhododendrons come from the acidic granite rocks of the Himalayas. To mimic these conditions, rhododendrons are almost always planted in acid peat in this country. Although this suits the soil preferences of the rhododendrons very much, peat is very poor in iron and magnesium and generally poor in nutrients. A good fertilizer for rhododendrons provides the plant with the necessary nutrients and, above all, brings the two micronutrients magnesium and iron with it. In addition, the plants are mostly shallow roots, which is particularly advantageous on slightly calcareous soils. If you do not find the optimal conditions in your garden, you can help with targeted fertilization. You only have to do this in the upper layers of the soil through which the rhododendron has roots. In the following, we will tell you how and with what best to fertilize your rhododendron.

Organically fertilize rhododendrons

The organic fertilization brings - not only with the rhododendron - some advantages compared to the mineral variant. While it may not work as quickly in the short term, it is the more sustainable choice in the long term. The following applies to rhododendrons: You should use fertilizers that lower the pH value, or at least those that do not affect the pH value. Fertilizing with compost is not necessarily recommended, because compost is very variable in its properties and often even has a rather high pH value. Rhododendron fertilizing with horse manure is a better option because horse manure is high in magnesium and iron. Composted horse manure should be used here, as fresh horse manure is far too rich in nutrients.

If you do not have access to such natural fertilizers or if you want to do without animal components in the fertilizer, you can fall back on long-term fertilizers in organic quality. This includes our mainly organic Plantura organic hydrangea fertilizer. This not only has the advantage of a long-lasting effect, but also provides rhododendrons and other bog plants with exactly what they are often lacking: iron and magnesium. It is also much better for the soil life of your garden. Also hydrangeas, blueberries, lingonberries, skimmias, and heather Lavender heather can be fertilized as needed with our hydrangea fertilizer, for example. Of course, our iron fertilizer for rhododendrons is safe for children as well as pets and garden animals. Below we have put together a guide for you on how to optimally fertilize your rhododendron organically.

Organic long-term fertilization: Application recommendation for rhododendrons

• Before planting 100 - 150 g / m² (about a large drinking glass full) of ours Plantura organic flower fertilizer work into the upper soil layer.
• Dig a wide planting hole and loosen it deeply. Pour the soil and freshly inserted rhododendron well so that the granules can dissolve well.
• With maintenance fertilization in spring and summer, you should fertilize another 80 - 120 g / m² (0.2 liter jar) per plant.
• To do this, push the mulch layer on the roots of the rhododendron to one side, distribute the fertilizer and water it well. But do not work this in, because the flat roots of the rhododendron should not be damaged.
• As the size of the rhododendrons increases, the fertilization can gradually increase to around 400 grams of ours Plantura organic flower fertilizer can be increased in order to maintain the vitality of the plant even in old age

Tip: Be generous when it comes to spreading the fertilizer over a large area for the rhododendron. Due to its shallow roots, the rhododendron can absorb nutrients far away from the trunk. So spread the fertilizer in a radius of one and a half to two meters around your plant.

Fertilize rhododendrons with minerals

the mineral fertilization offers a good opportunity in many areas to quickly intervene in the nutrient supply of our garden plants, especially when there are acute nutrient deficiencies. While mineral rhododendron fertilizers are well suited for short-term intervention, they often do not work long-term as depot fertilizers. It means that Blue grain and other mineral fertilizers must be applied more frequently than organic fertilizers. Because storage fertilization is not possible unless special and expensive depot fertilizers are used. Mineral fertilizers can even harm your rhododendron, because incorrectly dosed mineral fertilizers easily leads to over-fertilization, which in the best case only makes it susceptible to pests and frost cares. In the worst case, the so-called exosmosis at the roots can cause even greater damage to the plant. When using mineral rhododendron fertilizers, it is particularly important to always water sufficiently in order to dilute high nutrient concentrations. Iron fertilizers for rhododendrons are usually mineral, however, since iron is hardly present in most organic materials - including our mainly organic ones Plantura organic hydrangea fertilizer is supplemented by iron sulfate. It dissolves well in the soil solution and slightly acidifies it in order to improve absorption.

It is best to choose a gentle but effective variant for the plant and the environment and use one organic fertilizer that either naturally or by supplementing the iron and magnesium reserves of the soil replenishes.
tip: You can also fertilize organically or minerally with rhododendrons that have been planted in a tub. Due to the limited soil volume, however, nutrients cannot be stored well, which is why two doses per year are recommended in any case. Organic fertilization is particularly useful in the bucket, because mineral fertilizers are of no use all essential nutritional elements and also ensure that the potting soil collapses. Organic fertilizers like ours Plantura organic hydrangea fertilizer are simply distributed under the mulch layer, poured on and then covered again. You should give these nutrient bombs in small doses from April to mid-June. When fertilizing your rhododendron, we recommend 70 grams per square meter and season. Alternatively, you can dissolve five grams of blue grain per ten liters of water and use it to fertilize your potted rhododendron once a week. If you use mineral fertilizers, you should always give them enough water to avoid harmful ones Avoid concentrations of salt in the small jar so that the nutrients can be absorbed and burns be avoided. Mineral fertilized rhododendrons should also be repotted regularly in order to replenish important trace elements via new soil. Too extensive watering immediately after fertilization can also flush the nutrients out of the root area of ​​the shallow-rooted rhododendron and thus make them inaccessible.

Fertilize the rhododendron with coffee grounds

Coffee grounds are produced in almost every household on a daily basis. With a pH value of around 6.5, however, it does not meet the needs of rhododendrons because it is not acidic enough. Few people know, however, that after watering it can also be used to fertilize plants such as rhododendrons. The slightly acidic properties of coffee grounds can be used to lower the soil pH. However, the coffee grounds provide useful nutrients in small quantities that, with superficial incorporation, provide you with Released for a longer period of time, it also increases the level of organic matter in the soil, making it loose remain. In the Fertilizing with coffee grounds follow these steps:

• Dry the coffee grounds.
• Scatter coffee grounds in the root area under the mulch cover.
• But do not incorporate this.
• Pour well.
• Alternatively, you can pour the coffee grounds directly into the watering water and distribute them. With bed rhododendrons you can use coffee grounds up to four times a year. In a pot culture, it is best to fertilize once in April and mid-June.

You don't have a rhododendron in your garden yet and are you looking for a suitable variety or do you want to expand your stock? We will provide you with the most beautiful Species and varieties of rhododendrons before.