What is wrong with our rhododendron?

Toni Allardyce ccrhorse at netcom.ca
Sat Mar 25 01:38:21 EST 2000


I agree with the writer indicating a pathogen, specifically a vascular
disease. Verticillium , fusarium, phytophlora, all are similar in that they
indicate wilt, as seen in your photos. I notice the discoloring starts at
the base of the leaves near the stem indicating some type of vascular wilt.
Also, are your plant in a container? This would also lead to a problem with
drainage. I do not agree with the next writer , who thought it was a freeze.
I am in the area of Vancouver, BC and experience many cold periods with
below zero temps. My rhodos appear wilted for a time, to protect the leaves
from the cold and reduced xylem activity decreases water flow to the leaves.
Also check the Compendium of Rhododendron and Azalea Diseases, edited by
D.L. Coyier and M.K. Roane.
Leslie Kaplan <rushcreek at prodigy.net> wrote in message
news:8ahi61$36ja$1 at newssvr03-int.news.prodigy.com...
>
> I do not see any evidence of black vine weevil damage (notched leaves),
bugs
> which cause serious root damage in the larval stage.  I would say that
your
> rhodies are suffering from a fungus disease, eg. phytopera (sp?).  In
heavy
> soils, like the clay ones around here, the roots tend to deteriorate for
> lack of good drainage, and often these fungus diseases develop.  They
futher
> destroy the roots, and you see blackened stems and dead and drooping
leaves
> like the ones in you picture, one branch at a time, usually starting from
> the bottom, but sometimes affecting one side of the plant first.  No cure.
> Unfortunately, phytopthera does tend to linger in the soil, and it is
> recommended not to replant rhodies in the same spots.
>
>  Amending the soil with organic material (preferably acidic) and ground
pine
> bark, sometimes sold as 'Soil Conditioner' will help new plantings
survive.
> As far as light, they prefer eastern exposures, but are quite adaptable.
Do
> you ever fertilize?  If you do, use a light application formulated
> specifically for acid-loving plants.  Good luck.  I would remove the sick
> plant and hope for the best with the other.  Drought can be another stress
> factor.
>
> blah <blah at bleh.com> wrote in message
> news:38cc320b.12853429 at news.mindspring.com...
> >
> > Pictures of our sick plant at:
> >
> > http://www.mindspring.com/~alanwolf/diagnose/diagnose.htm
> >
> > Local plant people mumble about fungus or rot or bugs, or...
> > In other words, they have no idea.
> > These are expensive, and we've lost a couple to the same
> > symptoms.
> > Any ideas?
> >
> > They don't get too much light in our courtyard...
> >
> > Thanks.
> >
> > Alan Wolf
> > alanwolf at mindspring.com
> >
> >
>
>






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