Re: Rhododendron mucronulatum not doing well

Well, Chris, take heart in that rhodies are really subject to this
disease as well as several others; could even have come from the
nursery with it because it seems it's one of those diseases that
start in nurseries and get carried home with the plant, so it just
may have nothing to do with your care of the plant.

Ken Cox posted the following on the rhodie list a couple of years ago
about this:  "....if species are grown in black containers and badly
looked after and/or grown in sawdust or over-fertilised or over
watered as they often are in the Pacific Northwest then Phytopthora
is rampant.  I have seen some of your nurseries riddled with it and
if you see this sort of thing, when you visit, dont touch a single
plant, as the spores are carried via the irrigation system and is
easily transferred from one plant to another."

Rhodies are pickier about soil than the general evergreen azaleas in
my experience.  I have some evergreen azaleas (which are, of course,
rhodies, too) planted in amended clay that drains well; they were
planted in the soil and are doing fine.  However, most of my plants
are planted high -  a technique learned after losing too many plants
to the old clay soil bath tub effect...and used because most of my
property is a web of tree roots, making it very hard to dig and not
too good for the trees when I do. 

I plop them on top of the natural grade and fill around them with a
mix of sand, pine bark fines and/or peat and rotted leaf mold or wood
chips (whatever I've got) with only a very small amount of native
clay mixed in.  Have to retain this, of course.  I use rocks or logs
or whatever is handy and then mulch.  This light mix will dry out
faster in hot summer weather and requires watering, but it suits this
genus and they thrive in it because it drains really fast.  I very
seldom feed any of my plants; once in a blue moon they might get a
handful of Hollytone, but so seldom it hardly counts.  Keeping a
continual pine bark mulch on them feeds them enough; they do not like
hardwood mulches very much.

Probably removing fruit wouldn't hurt, but if it's got root rot, it
ain't a gonna help much, either.  Few plants recover from a bad case
of Phytophthora root rot, I am sad to say.

Of course, it could also be that they are simply waterlogged and
haven't got the Phytophthora...that's why digging it up and checking
is a good plan; there's always hope:-)

Marge Talt, zone 7 Maryland
mtalt@hort.net
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----------
> From: Christopher P. Lindsey <lindsey@mallorn.com>
> 
> On May 18, Marge Talt wrote:
> > Well, Chris, this one wants  moist, cool, acidic, well-drained,
> > organic soil and is subject to phytophthora root rot on wet,
heavy
> > soils.
> 
> Thanks, Marge.  I was afraid that it might be something like
Phytophthora,
> but was hoping others would come to different conclusions.  :)  
> 
> I did some poking around on the Web and found a good page that
discusses
> the disease in detail:
> 
>    http://www.cas.psu.edu/docs/CASDEPT/PLANT/ext/phytoph.html
> 
> Unfortunately, it sounds like there's no cure if the plant is
already
> infected.
> 
> > I have a feeling your soil may not be naturally acid enough,
given
> > where you are.  I can't remember if it's clay or not, but if it
is,
> > did you plant this child high when you planted it?
> 
> The soil does have a lot of clay, but it was also a heavily amended

> bed.  But there's also been a lot of rain lately.
> 
> > If it were mine, I'd probably dig it up to check out the root
system
> > and then, if it has any living roots, replant it in a raised
> > situation in a light mix composed of pine bark fines and/or peat
and
> > sand; mulch with pine bark mulch and talk to it nicely and see if
it
> > recovers.
> 
> I'll check out the plant and see if I can find further signs of
infection.
> If not, I'll replant in amended soil and see if it does any better.
 
> Otherwise, it looks like it's curtains for that guy.  :(
> 
> Someone else suggested via personal email that I cut off the fruit
to 
> help save the plant's energy, so I'm going to do that as well.
> 
> Chris

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