Rhododendron: Do I need to cut back dead stems?

(Question)

First of all I really appreciate your answer to my previous question: https://www.torontomastergardeners.ca/askagardener/does-my-rhododendron-look-fine/

As advised, I waited patiently for the temperature to become higher. And yes, it did start showing green new sprouts sort of randomly (some stems had them upper, some had just around the ground)! Even one old-looking bud was actually alive and had a flower. Which surprised my neighbor, too!

Now I’d like your advice again.. It seems to me that almost half of the entire plant (half stems) does look dead. What to do with them? Also do I have to remove all those hard brown leaves from the stems that had new sprouts?

Thank you.

(Answer)

Thank you for contacting Toronto Master Gardeners about your rhododendron. We are pleased that your shrub has started to grow again.

You can remove any dead or damaged rhododendron branches anytime during the year. Make sure any branches you plan to remove are dead before cutting them away by slightly scraping the outer layer of bark. If it reveals green, the branch is still alive and is likely to recover. If it is brown, the stem is dead.

There is no need to remove the brown leaves on stems with new growth. Leaving the dead leaves on will avoid accidentally damaging the new growth.

The best time to prune living stems is immediately after flowering in the spring before next year’s buds start to form. Note that these buds will start to set shortly after this year’s blooms have finished.

You may want to carefully deadhead (remove) the spent blooms to direct the plants energy into foliage growth rather than seed production.  Again, be careful not to remove any new buds forming beneath the spent blooms.

For more information on rhododendron pruning, check out this article from The American Rhododendron Society.