Rhododendron is another plant for which deadheading by cutting may be
disrecommended. In this case the problem is that you can't cut off the
flower heads without taking out the new buds.

There are enough buds so that if you carefully cut at the base of the
flowers you will not hurt it.
But there is an abscission layer just above the buds that breaks cleanly
if you bend the stem just below the flowers if you don't want to risk
cutting
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