Rhododendron care: watering, fertilizing & cutting

The rhododendron blossom makes the gardener's heart beat faster. But for it to bloom abundantly, it must be properly cared for and protected from disease.

Rhododendrons (rhododendron) are one of the largest genera within the heather family (Ericaceae). With more than 1000 species worldwide, the rhododendron is geographically represented almost everywhere. It is therefore hardly surprising that it can be attacked by a wide variety of pests and diseases. We provide tips on proper care and effective control of pests and diseases so that your rhododendron can continue to bloom in all its glory.

Maintaining rhododendrons

The rhododendron is relatively easy to care for. However, at certain times of the year he wants some attention from you. We reveal what you should pay attention to with the right care. Before we start with it, however, it should be said that the

Planting the rhododendron attention should be paid to certain points. Rhododendrons want a slightly acidic soil and abhor waterlogging. Many soils, especially in southern Germany, are more neutral to slightly basic. It can therefore be an advantage to dig a large planting hole and use a special rhododendron soil to fill.

Water the rhododendron properly

Especially when the rhododendron plants are still small, they want to be watered regularly. However, this must not cause waterlogging, as the rhododendron, as a shallow-rooted shrub, is very sensitive to this. The bigger and older the rhododendron gets, the less often it has to be watered, as the roots are now stronger. Signs of the need to water can be hanging flower buds or curling leaves during flowering.

Note: You can water your darling at longer intervals, but then with a little more water. Particularly during dry periods, water that is too small can evaporate quickly before it penetrates the soil.

Fertilize rhododendrons

The rhododendron is particularly happy about long-term fertilization. The best time to do this is in spring, which means shortly after planting with freshly planted bushes. Work the fertilizer into the surface of the roots so that the nutrients can be better absorbed into the soil. You can also mix horn shavings, compost and / or coffee grounds with the excavated soil during the planting process and then put it back into the planting hole. These fertilizers are all purely organic, some have slightly acidic properties for the soil and have a positive effect on soil life. While coffee grounds increasingly lower the soil pH value, but are not a very large supplier of nutrients, the compost takes on the task of long-term nutrient supply. Horn shavings (or horn meal) do not affect the soil pH value, but also ensure long-term nutrient release with a high nitrogen content. Those who prefer to fertilize regularly than to use slow-release fertilizers will stop fertilizing from October to initiate the resting phase.

For your darlings who have already taken their place in the garden for a long time, the expert recommends the Give the shrub an energy boost a few weeks before flowering with a mixture of mineral and organic fertilizers miss. You can find out more about this in the video.

In addition to the home remedies mentioned above, there are also special rhododendron fertilizers on the market that cover the whole Cover the spectrum of nutrients and also (partially fully organic) deliver nutrients in the medium term. Also a primarily organic bio-fertilizer like ours Plantura organic hydrangea fertilizer is suitable for rhododendrons. The long-term fertilizer releases its nutrients gently and over a longer period of time to the rhododendron and also supplies it with iron.

Note: Under special circumstances, a second fertilization can also be carried out in summer. However, this is only necessary if a nutritional deficiency manifests itself in the form of yellow and withered leaves.

More about the right one Fertilizing your rhododendron You will find here.

Cut rhododendron

In principle, the rhododendron does not need any special pruning to bloom profusely. With increasing age, however, there is also increased lignification of the shoots, which is why a rejuvenation cut makes perfect sense if necessary. A radical rejuvenation cut should be made before flowering, as this will not waste the energy reserves of your rhododendron unnecessarily and nesting birds will not be disturbed.

Use sharp secateurs to cut off old shoots so that the bare interior of the shrub gets light again. It is important to make sure that you cut the shoots at an angle. This way, no dew or rainwater collects on the open areas of the shoots, which could cause diseases to penetrate. If you don't want to make a radical rejuvenation cut, but only want to keep the shape of your rhododendron, you can carry out a comprehensive maintenance cut immediately after flowering. This removes unsightly, diseased and injured shoots until you are satisfied with your favorite's growth habit again.

More tips and tricks for the Cutting back your rhododendron, we have put together for you here.

Care for the rhododendron after flowering: break out flowers

After you've made a full cut, there is still some good thing you can do for your rhododendron. To do this, simply break off all the dead flowers on the remaining shoots. This promotes the formation of buds in the next year and removes spore centers, which prevents infestation by fungal pathogens.

Transplant rhododendrons

You may need your Transplant rhododendrons. We have summarized the best way to do this in a special article.

Rhododendron diseases

The genus of the rhododendrons is particularly susceptible to fungal diseases, but animal pathogens also wreak havoc in the evergreen foliage of the rhododendron.

Rhododendron has yellow and brown leaves

The discoloration of the leaves usually has two causes: Either the plant was cared for incorrectly or it was attacked by a fungus. In order to do something about the discoloration, the source of the damage must first be identified. Chlorosis from improper maintenance can either be caused by a soil that is too calcareous or a lack of nitrogen. With fungal infections, different yellow or brown lesions form depending on the pathogen.

You can find a list here more common fungal diseases of the rhododendron, as well as all diseases that can occur due to animal pathogens.