Fertilize rhododendrons: Tips on fertilizer and timing

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

the rhododendron (rhododendron) is a genus of shrubs from the heath family (Ericaceaea). In nature, the genus grows primarily in acidic locations with a very permeable subsoil. And the fertilization should also be adapted to these special conditions. We will tell you how you can create the perfect conditions in your home garden and which fertilizers are particularly suitable for your rhododendron.

Rhododendrons are adapted to an acidic, humus-rich and well-drained substrate. Deficiency symptoms are very often observed in them, especially yellow leaves. In many cases, the reason for this is a nutrient deficiency: nitrogen, iron or magnesium deficiency can lead to yellow leaves on rhododendrons. To remedy this, however, 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. it is no longer nice and acidic, the acid-loving plant is less able to absorb iron efficiently - even if there is sufficient iron in the soil. It is therefore particularly relevant when Rhododendron plants directly to ensure the acidification of the soil.
If the soil is then acidic enough, you can fertilize your rhododendron so that it is very special radiates - in the following we explain the important questions about the fertilization of the popular shrubs.

When should you fertilize rhododendrons?

Most rhododendrons will be fine with a fertilization once a year, but when you fertilize your rhododendrons is important. An organic long-term fertilizer like ours is also best suited for this Plantura organic flower fertilizer, which 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 not be fertilized later than mid-June so as not to endanger the frost hardiness. If you want particularly lush growth, you can also apply two fertilizations at the beginning and end of early summer, but one fertilization is sufficient for the health of the shrub. In special weather conditions or unfavorable site conditions, a second fertilization in early summer can also make sense. You should consider this, especially 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 reserve fertilization 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

Eria plants such as rhododendrons have shallow roots and love moderately nutrient-rich, humus-rich and well-drained soil with an acidic pH 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 acidic peat in this country. Although this suits the soil preferences of the rhododendrons, peat is very low in iron and magnesium and generally low 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 flat-rooted, which is particularly advantageous on slightly calcareous soils. If you don't find the ideal conditions in your garden, you can help with targeted fertilization. You only have to do this in the upper layers of soil through which the rhododendron has rooted. In the following we will tell you how and with what you can best fertilize your rhododendron.

Fertilize rhododendrons organically

Organic fertilization brings - not only with rhododendrons - some advantages over the mineral variant. While it doesn't work as quickly in the short term, it's a more sustainable choice in the long run. The following applies to rhododendrons: you should use pH-lowering fertilizers or at least ones that do not affect the pH. Fertilizing with compost is not necessarily recommended, because compost is very variable in its properties and often even has a rather high pH value. Fertilizing rhododendrons with horse manure is a better option because horse manure is rich in magnesium and iron. However, 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 want to do without animal components in the fertilizer, you can use long-term organic fertilizers. This includes our primarily organic Plantura organic hydrangea fertilizer. This not only has the advantage of a long-lasting effect, but also provides rhododendrons and other ericaceous plants with exactly what they often lack: iron and magnesium. It is also much better for the soil life in your garden. Also hydrangeas, blueberries, cranberries, skimmia, and heather lavender heather can, for example, be fertilized as required with our hydrangea fertilizer. Of course, our iron fertilizer for rhododendrons is safe for children, pets and garden animals. Below we have put together instructions 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 top layer of soil.
• Dig a wide planting hole and loosen deeply. Water the soil and freshly planted rhododendrons well so that the granulate can be easily loosened.
• For maintenance fertilization in spring and summer, you should fertilize another 80 - 120 g/m² (0.2 liter glass) per plant.
• To do this, push the mulch layer on the roots of the rhododendron aside, 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 rhododendron grows in size, fertilizer can be applied gradually to around 400 grams of ours Plantura organic flower fertilizer be increased in order to maintain the vitality of the plant even in old age

Tip: Be generous when it comes to distributing the fertilizer for the rhododendron over a large area. Due to its shallow, sprawling roots, the rhododendron can also 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 as long-term depot fertilizers. It means that blue grain and other mineral fertilizers have to be applied at shorter intervals than organic fertilizers. Because stock fertilization is not possible unless special and expensive depot fertilizers are used. Mineral fertilizers can even damage your rhododendron, because an incorrectly dosed mineral fertilizer gift easily leads to over-fertilization, which at best only leads to susceptibility to pests and frost cares. In the worst case, the so-called exosmosis at the roots can cause even more severe damage to the plant. It is particularly important when using mineral rhododendron fertilizers to always water sufficiently to dilute high nutrient concentrations. However, iron fertilizers for rhododendrons are usually mineral, since iron is hardly present in most organic materials - even our primarily organic ones Plantura organic hydrangea fertilizer is supplemented by iron sulfate. It dissolves well in the soil solution, slightly acidifying it to improve absorption.

It is best to grab a gentle but effective variant for plants and the environment and use one organic fertilizer that either naturally or by supplementing the soil's iron and magnesium stores fills up.

tip: You can also use organic or mineral fertilizers for rhododendrons that have been planted in a bucket. However, due to the limited soil volume, nutrients cannot be stored well, which is why two doses per year are recommended in any case. Organic fertilization makes a lot of sense, especially in buckets, because mineral fertilizers do not work all essential nutrients 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, 70 grams per square meter and season is recommended. Alternatively, you can dissolve five grams of blue seed per ten liters of water and fertilize your potted rhododendron with it once a week. If you use mineral fertilizers, you should always give them enough water to avoid harmful substances Avoid salt concentrations in the small vessel so that the nutrients can be absorbed and burns be avoided. Mineral fertilized rhododendrons should also be repotted regularly in order to supplement important trace nutrients with new soil. However, over-watering immediately after fertilization can also flush nutrients out of the root zone of shallow-rooted rhododendrons, making them unavailable.

Fertilize rhododendrons with coffee grounds

Coffee grounds are a daily occurrence in almost every household. With a pH value of around 6.5, however, it does not meet the needs of rhododendrons because it is not acidic enough. However, only a few know 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 soil pH. However, in small amounts, the coffee grounds provide useful nutrients that, if incorporated superficially, over a be released over a longer period of time, and also increases the organic matter content of the soil, making it loose remains. In the Fertilization with coffee grounds follow these steps:

• drying coffee grounds.
• Scatter coffee grounds in the root area under the mulch layer.
• But don't incorporate this.
• Pour well.
• Alternatively, you can also put the coffee grounds directly into the irrigation water and distribute them. With bedding rhododendrons you can reach for coffee grounds up to four times a year. In a pot culture, it is best to fertilize once in April and mid-June.

Do you not yet have a rhododendron in your garden and are you looking for a suitable variety or do you want to expand your stock? We present you the most beautiful ones Rhododendron species and varieties in front.