Cut rhododendron correctly – instructions

The rhododendron usually keeps an attractive shape all by itself. For a decorative look, the waste is not necessary in the first place. At least not in the first few years. Nonetheless, it makes sense. This is because rhododendrons tend to become bare as they get older. The lower area in particular is then quite unsightly.

If you don’t want to part with the shrub directly, you can counteract this quite easily. An annual, light topiary or gentle corrective measures prevent it from getting that far in the first place. If the rhododendron is already bare, a rejuvenating pruning can stimulate it to sprout again and grow densely. However, attention must be paid to the type, because some benefit quickly and visibly from radical blends. Others enter through the measure.

species

The rhododendron can be distinguished not only in different varieties, but also in the way of propagation and processing. So there are rhododendrons propagated by cuttings and refined forms.
The grafted rhododendrons are superior in number. But these of all people take it amiss if they suddenly lack too much leaf mass. If they are cut too much all of a sudden, they may not grow at all. A rejuvenation cut is still possible, but must be carried out in several stages.

The cuttings propagated editions are much easier to care for. They can also be radically pruned all around and will also sprout again if they no longer have a single leaf after the measure.

Rhododendrons that have been grafted and propagated by cuttings differ visually in the grafting stage in the lower area of ​​the trunk. If the associated thickening and scar is difficult to see – i.e. it cannot be assumed with certainty that it is propagated by cuttings – it is better to cut gently. Otherwise there is a risk of the plant dying.

topiary

As already mentioned, an annual topiary or corrective shortening can be dispensed with. Nevertheless, they are advisable. However, only from the second year. Only then will the plants have developed enough roots to be able to absorb the loss and recover quickly.
When making corrective blends, it is advisable to observe the following instructions.

• Cut back individual, thin and protruding shoots down to the next larger piece of wood
• Pay attention to straight cutting surfaces
• Do not cut into the old wood
• Thin out the crown gently
• Remove a maximum of a quarter of the leaf mass per cut
• Shorten weak shoots in the lower part of the rhododendron

If these corrections are carried out continuously annually, the bareness will be reduced. In addition, the plant can recover more easily and does not look ‘plucked’. It is essential to ensure that the process is very gentle and that only the bare essentials are removed when cutting waste. Going too radical will weaken the rhododendron. You also have to make sure that the budding after the blend is not visible too quickly. Growth is not accelerated. Corrective cutting should therefore be as inconspicuous as possible.

taper cut

If the rhododendron is already bare in the lower area, only a rejuvenating cut will help here. And this has to be quite radical. Since the grafted rhododendrons in particular cannot tolerate a sudden pruning in one year, it should be spread over at least two years.
The following instructions show you how.

1. In the first year of tapered pruning, only half of the rhododendron is trimmed. Every second shoot is cut up to about 40 cm above the ground.
2. It should be noted that the trimmed shoot is surrounded by long shoots and is literally covered.
3. If you don’t want to rely on your sense of proportion, you can count and mark the branches. In this way, no unwanted holes appear in the plant.
4. The cut wounds are somewhat protected by the surrounding branches, but treatment with wound wax is recommended for large branches.
5. In the second year of pruning, the corrected shoots will already have sprouted new leaves. Now the still long branches can be cut.
6. The remaining shoots are cut up to about five centimeters below the already short branches. In this way, the cuts are in turn protected by the leaves present.

tips

To ensure that the rhododendron can recover fairly quickly after cutting and the risk of infection is small, a few precautions should be observed.

• Make straight cuts, do not leave oblique cuts
• If necessary, rework frayed cuts with a sharp knife
• Thoroughly clean and disinfect cutting tools before use
• Check for signs of diseases and pests before starting work – do not cut if infested
• Only seal very large cuts with wound wax
• Do not blend in direct sunlight

Despite all caution, one should note that the rhododendron does not grow very quickly. Not even after a cut. After particularly radical interventions – even if these take place in individual steps over several years – it takes quite a while for rhododendrons to recover. For larger plants, it takes up to five years before the crown is fully restored. With the right aftercare, however, this process can be accelerated. However, hobby gardeners should not expect miracles.

aftercare

Pruning weakens the rhododendron, even if it turns out quite gently. Due to the leaf mass, the shrub also loses the ability to provide itself with sufficient nutrients. These must be added in the form of fertilizer. Immediately after cutting, it is therefore advisable to treat the rhododendron to some fertilizer.

Special rhododendron fertilizers, horn shavings, compost and fresh bark mulch are suitable. The surface of the soil can be slightly loosened for better absorption. However, not too deep so as not to injure the roots. Furthermore, it must be poured abundantly after cutting and fertilizing. Otherwise, the supply of nutrients becomes a dangerous burden that can chemically burn the roots.
The rhododendron may not initially be moved or repotted after a radical rejuvenation cut. Only when the plant has recovered after the second year of pruning and has sprout all over again can the location be changed. Intact roots are of particular importance for the weakened shrub, transplanting could endanger them and thus the entire plant.

time

Rhododendrons can be pruned between late summer and early autumn, i.e. from September to early November. But also towards the end of winter, i.e. around February.

Those who prune late in the year should only make slight corrections. Otherwise, the plant will lose too much vigor before winter. For radical interventions, the end of winter should be preferred. Then, however, a good part of the flowers must first be dispensed with. This is the case with a radical blend anyway.

Implement

It has already been mentioned that the rhododendron should not be transplanted shortly after heavy pruning. However , transplanting to a new location can also be an alternative to cuttings. At least when the reason for the maintenance measure is the unexpected size of the rhododendron.

If the location is not suitable for other reasons, radical cutting and transplanting should not be too close together. A time interval of two years is safe. Only then did the plant have enough opportunity to develop enough root mass. This is not only important for the supply of nutrients. The necessary water pressure in the rhododendron also depends on it.

When cultured in a tub, the distance can be smaller. A year should pass between repotting and trimming the rhododendron. Patience and appropriate planning are required here.

vitality

Because the rhododendron can resent the pruning – depending on the variety – other weakening factors must urgently be avoided. The vitality of the plant is crucial. If the plant has just survived an infestation with pests or a disease, the scissors or saw should never be used. On the one hand, the rhododendron is still weakened and burdened by this. On the other hand, with infections there is a risk of bringing any germs that may still be present directly onto the cuts and making it easier for them to penetrate. Even with immediate treatment, the chances of survival are then slim. The same is true of parasites. Open spots in the wood are welcome opportunities for some pests.

It is therefore of crucial importance that the control measures have been completed for some time and that the crop has fully recovered. In addition, of course, you have to make sure that you don’t overlook diseases or parasites when blending. A detailed check for discoloration, coverings, drill holes and signs of eating – and of course the pests themselves, should not be forgotten before the measure.

If in doubt, you should initially refrain from cutting the rhododendron and continue to monitor whether an infestation is actually present. Alternatively, the cuts can be disinfected and sealed with wound wax.

Of course, the rhododendron should also be well fertilized and watered. The better the condition before pruning, the faster the plant will recover. This is also a visual advantage.