how-to: planting and caring for rhododendron
In general rhododendron are tough plants if you respect their basic requirements. You should pay attention to picking right location and make sure that you plant in the right soil texture. In the following we´d like to give you some tips and advice for the right care to make sure that you´ll enjoy your rhododendron for a long time.
Rhododendron are flat rooting with fine roots that prefer airy ground.
The ancestor of the modern Rhododendron lived mostely in regions with light forest as well as mountain slopes. The ground there is airy, loose and limepoor as well as evenly humid.
Of course you usually won´t find these kind of optimal conditions
in your own garnden. Therefore you should do some preliminary work in front of the planting to make sure your rhododendron thrive.
picking the right location
hybrids prefer light shadow from oaks or pines that safe them from the full force of the noon time sun. Full shadow in turn should be avoided, as rhododendron tend to grow less opaque and bushy and create less buds in full shadow.
In grounds with sufficient humidity rhododendron can be planted in full sun as well. Especially well suited for sunny locationas are the yakushimanum varieties because of their very compact growth and their protective pelt on fresh shoots. Decidious Azalea have no problem at all with sunny locations.
Like with any other type of plant there are fast growing as well as slow growing rhododendron that vary in maximum diameter and height as well. That should already be considered while planting them.
Dwarf azalea and dwarf rhododendron should be fine with 50 cm distance, decidious azalea and yakushimanum should habe 80-100 cm of distance for hybrids it can be 150 cm or more. This is valid in case you don´t want a group planting where the plants grow into each other. The room between the plants can be strewed with pine bark or being planted with ground covering plants. The ground covering plants will then be pushed back by the growing rhododendron.
preparing the ground
Generally rhododendron prefer loose, humus rich soil. Depending on the ground in your garden the preliminary work varies.
If you have limepoor sandy ground or soil ground the diameter of the hole for the rootball should be twice as big as the rootball. Afterwards the hole should be filled up with peat or rhododendron substrate. If you have good ground you can mix the digged out ground 1 on 1 with peat or substrate.
If you have loamy or calcerous
ground it´s recommended to dig the hole at least 50 cm deep and keep a diameter of 150 cm aroung the rootball. You should only fill up the hole with peat or rhododendron substrate, you should not mix it with the digged out ground. If you have loamy ground you should dig minimum 10 cm deeper and fill in a drainage layer with coarse sand before you fill in the peat or substrate.
The best time for planting is between September and November. In this time the plant automatically get enough water and it´s still warm enough for good root growth. This give the plant an easy start next spring. Also suitable for planting are the months March and April. Besides the preparation of the ground you need to make sure you don´t plant the rootball to deep. The top of the rootbal should be in line with the ground. To make sure it´s fine it´s ok to let the rootball stand 1-2 cm out of the ground. After the planting the surrounding ground shold be softly hard-packed. After you waterer the fresh planted rhodo well you can strewed with pine bark (estimately 5cm) to avoid quick drying out.
In spring and summer you should fertilize your rhododendron. Rhododendron fertilizer or horn shavings are recommended. A well fed plant is way more healthy and resistant against deseases and pests.
You should water your rhododendron regularly in the first years, but not too much. Rhododendron like light humid soil but they can´t get along with jam wetness.
As rhododendron are flat rooting you should avoid too much tillage underneath your rhododendron.
For an optimal growth you should remove the remains of the flowering after flowering is done. This way the plant saves energy that it can invest into it´s growth. Most importantly this ensures a bushier plant with more branches and and overall more beautiful growth.