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Author Topic: Rhododendron hirsutum problem  (Read 1505 times)

Corrado & Rina

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Rhododendron hirsutum problem
« on: October 08, 2016, 11:02:58 AM »
Dear all,

I have some issues with a Rhododendron hirsutum after a not brilliant summer.

Here re the pictures:
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551586-0
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551588-1
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551590-2
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551592-3
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Any clue about what it is and how to deal with it? Is it natural this time of year?

Best,

Corrado (& Rina)



« Last Edit: October 08, 2016, 11:09:40 AM by corradoerina »
Corrado & Rina

Corrado & Rina

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Re: Rhododendron hirsutum problem
« Reply #1 on: October 08, 2016, 11:03:43 AM »
551596-0
Corrado & Rina

johnw

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Re: Rhododendron hirsutum problem
« Reply #2 on: October 08, 2016, 01:50:20 PM »
Likely one of the Pythiums or Phytophthoras so the prognosis is not good.  You could start chopping back from the top down with pruner dips in between cuts until you reach healthy green wood.  Unlikely the results will be good; off drainage or uneven watering to blame as a rule and/or very warm soil. 

BTW that species is notoriously difficult in pots but rather easy in the ground with good drainage, and a bit of lime or bonemeal as I recall.

john
« Last Edit: October 08, 2016, 08:58:50 PM by johnw »
John in coastal Nova Scotia

Robert

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  • All text and photos Robert Barnard
Re: Rhododendron hirsutum problem
« Reply #3 on: October 08, 2016, 02:13:48 PM »
Also keep in mind that over fertilizing with high end nitrogen fertilizers can cause problems (even time release types, especially in warm weather). My experience has been that an excessive build up of nitrogen in the plant tissues creates a situation where they are much more susceptible to pythium and phytophthora pathogens.

From what I see in the photographs the likelihood of recovery seems slim, however do not give up. Also, all is not lost if the plant(s) die. Such situations can be very good learning experiences. I like to look at all the various aspects of the plants culture to analyze what might have gone wrong or could be done differently for the benefit of the plant. This way I learn and am a better gardener.
Robert Barnard
Sacramento & Placerville, Northern California, U.S.A.
All text and photos Robert Barnard

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