Last updated on October 23rd, 2023 at 08:54 pm
Rhododendrons do not really need to be pruned, but pruning is still useful in many cases to ensure beautiful flowering. What you need to pay attention to, you will learn below.
Rhododendron is a popular flowering shrub, which can be found both in parks and in the wild. In the spring it attracts all eyes with its purple, white or pink flowers.
When to prune rhododendrons?
The right time for maintenance pruning is February and March, and July through November. Make sure that no nesting birds have established themselves in the shrub. Good to know: Rhododendron is poisonous, so always wear gloves when caring for the plant.
What are the three types of pruning?
You have three options for your rhododendron pruning:
- Pruning: This is not considered a true pruning. Rather, only the withered flowers are removed here.
- Topiary: Topiary is about maintaining the shape of the rhododendron.
- Radical rejuvenation pruning: If the rhododendron has become bare from the inside or has grown too large, radical rejuvenation pruning is the solution. However, you must keep in mind that flowering may not occur for two to three years after this.
- Prune out the rhododendron
- After flowering, you should remove the wilted flowers promptly. This is important so that there is room for new buds and the shrub also has more strength to grow.
Light topiary is used to shorten shoot tips and remove diseased or old shoots. Be careful not to miss the right time. It’s best to do the topiary before new shoots appear.
Instructions: This is how a rejuvenation pruning works.
When should you avoid radical pruning?
Heavy pruning must be well considered, because the delicate shrub does not always recover from it. Therefore, before pruning, check whether the flowering shrub is well rooted. After all, if it grows on unfavorable soil, it can slowly become bald from below and still bear green leaves. In this case, instead of pruning, it is recommended to lift the plant out of the ground. Rejuvenation pruning here would not favor the desired root pressure, so that new shoots can develop.
When is radical pruning suitable?
If you can ensure that the plant has firmly rooted itself in the ground over the years, then it will survive pruning well.
Use pruning shears to shorten the branches to about 30 to 50 inches in length. If it is an older rhododendron, thicker branches may also be shortened with a pruning saw. Good to know: New buds form on the dormant eyes of woody shoots.
Follow these tips when pruning
Make sure pruning shears are sharp and it’s best to wear gloves. Set the cut at a slight angle after a shoot branches, and be sure not to injure buds that have already formed.
If you want to go easy on your rhododendron, you can also split the rejuvenation pruning over two years to avoid losing all the leaf mass. Carefully cut back the shrub in the first year. And then in the second year to the desired size. Cut large saw wounds smooth with a knife and treat them with a wound closure product afterwards.
The right tool
First and foremost, the tool must be clean and sharp to prevent the transmission of pathogens when cutting back.
Care tips for after pruning
After pruning rhododendrons need to be well cared for. Provide the shrub with horn shavings or special rhododendron fertilizer. In addition, the shrubs need a new layer of mulch and sufficient lime-free water. Important: Do not replant your rhododendrons for two years after pruning, otherwise there is a risk that the plant will not sprout again.
You also need patience! This is because the evergreen shrub needs some time to regenerate. It can take up to four years for the crown to look beautiful again and for new flower buds to form. In the spring, you should shorten all unbranched new shoots again a little, so that the crown can grow compactly.