How to Save a Dying Rhododendron

Is your Rhododendron looking a little long in the tooth? Our expert tells you how to give it a new lease on life

The colourful Rhododendron is extremely beautiful when properly maintained

Q: My neighbour is upset that her very old rhodoendron flower appears to be dying. Any clue as to what might be the problem?

There are several factors that could result in a rhododendron looking like it is dying. The plant could have originally been planted too deep, or mulch applied over the years may have buried the roots deeper than the plant prefers. Check at the soil level to ensure any branching is clearly above ground.

Root rot due to poor drainage is another possible problem, so check that your site is not soggy. Fungal stem diseases may cause cankers that eventually girdle the stems. This may also interfere with moisture movement in the plant.

Control measures involve pruning out the infected areas. Ensure pruning tools are properly sterilized before and after this procedure. There could be some damage to the trunk due to a rodent, or a mechanical source such as a weed trimmer or lawn mower. Look for damage to the stem at the soil level or above. Is there any disturbance to the planting site, such as digging or soil renovation?

Soil contamination from some unknown product intentionally or accidental spilled, or from lime leaching from a new concrete walkway, could also be the culprit.