About 1/3 of the leaves on my Rhodo have turned brown on the edges.
For the information of Forum users:
Gardening related questions are forwarded to the Vancouver Island Master Gardeners (through the Gardening Advice Line at Milner Gardens & Woodland). The volunteers review and answer questions each Tuesday afternoon and will generally have prepared an answer by the following Thursday.
Responses from other CVHS members are encouraged and appreciated!
Many thanks to Milner Gardens & Woodland’s Gardening Advice line, a partnership between Vancouver Island University’s Milner Gardens & Woodland and the Vancouver Island Master Gardeners Association for the following answer:
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First of all, thanks for a nice clear photo. It really helps to see the details of the problem.
Brown patches on rhododendron leaves can be caused by sun scald (if the brown leaf edges occurred before winter) or frost damage. The affected leaves can be trimmed off and there is no ongoing threat to the overall health of the plant. However, the brown ends also have grayish splotches on them which could indicate a fungal infection. Fungal infections take hold at points of injury so prune off anything that looks broken or damaged. Trim off and dispose of all affected leaves and stems. Clean any leaf debris off the ground as well.
There are also spots on the leaves which may be characteristic of this rhododendron variety. It is normal for some rhododendrons to have discoloration and shedding of leaves (called senescence). Spotting can also be an indication of fungal infection. Once the leaves are in a weakened state, they are vulnerable to diseases.
Follow up with good care to help the plant recover. The shallow root systems of rhododendrons need ample water during spring and summer and even during the winter if they are under cover of any kind. Mulch well to help retain moisture. Avoid any deep hoeing or raking which will damage roots. Avoid overhead watering which leaves excess moisture on the leaves, which creates an environment that is conducive to funguses.
I do hope this is helpful.
Marion
extension.oregonstate.edu/news/give-rhododendrons-azaleas-annual-check-each-spring
hortsense.cahnrs.wsu.edu/fact-sheet/rhododendron-leaf-spot/
Vancouver Island Master Gardeners Association
Phone: 250-752-0312
Email: GardeningAdvice.MilnerGardens@shaw.ca
Web: www2.viu.ca/milnergardens/gardening-advice.asp
Milner Gardens & Woodland’s Gardening Advice is offered through a partnership between Vancouver Island University’s Milner Gardens & Woodland and the Vancouver Island Master Gardeners Association.
Advice is given without charge and although it is believed to be correct, it is given on the basis that there is no liability on the part of the Master Gardener, VIU, or the Vancouver Island Master Gardeners Association.
Many thanks for all the excellent information.