Musings re Sick Rhododendrons and Azaleas
 

I know we have some people here who are quite knowledgeable about
rhododendrons and azaleas, so I want to ask a question. First,
let me say that we had a very lush-looking, perfectly healthy
rhododendron that has looked sickly ever since it was trimmed (not
at my behest, by the way--in fact, I was nearly apoplectic). At
the same time, possibly before this trimming took place, a very
sick, practically defunct azalea was severely trimmed back. We
read here that we are supposed to be very careful about
transmitting diseases--that we should sterilize our clippers
between every cut. Obviously, landscaping companies don't do
that. Not only that, but they would not sterilize their clippers
before they went to the next yards, and the next.

Okay, so I see a lot of sickly rhododendrons around now. I am
wondering whether, instead of being a natural phenomenon that is
mysteriously spread through the air, these blankety-blank
landscaping companies are spreading these diseases with their
clippers?

And we can broaden this and ask what else is being spread by
them?

--
Jean B., 12 miles west of Boston, Massachusetts, USA

Musings re Sick Rhododendrons and Azaleas
 

"Jean B." wrote:

Okay, so I see a lot of sickly rhododendrons around now. I am
wondering whether, instead of being a natural phenomenon that is
mysteriously spread through the air, these blankety-blank
landscaping companies are spreading these diseases with their
clippers?

Most causes of generaly poor behaviour of rhododendrons is cultural, not
disease. A healthy rhododendron is very resistant to disease. There
are diseases that spread in the soil, but very few that are spread by
pruning.

The biggest cultural problems are walnut roots or leaves, high soil
temperatures, drought, too moist a soil and over watering, lack of iron
available in the soil and alkaline soil, improper planting and root
stangulation, wind damage, sunburn, fertilizer burn, herbicide burn,
salt burn, etc. Rhododendrons are very sodium sensative, so winter use
of sodium salts is very toxic to them. On the other hand potassium
salts are beneficial of not used in excess.

--
Pardon my spam deterrent; send email to
Visit my Rhododendron and Azalea web pages at:
http://www.users.fast.net/~shenning/rhody.html
Also visit the Rhododendron and Azalea Bookstore at:
http://members.aol.com/rhodyman/rhodybooks.html
Cheers, Steve Henning in Reading, PA USA http://www.users.fast.net/~shenning

Musings re Sick Rhododendrons and Azaleas
 

"Stephen M. Henning" wrote:

"Jean B." wrote:

Okay, so I see a lot of sickly rhododendrons around now. I am
wondering whether, instead of being a natural phenomenon that is
mysteriously spread through the air, these blankety-blank
landscaping companies are spreading these diseases with their
clippers?

Most causes of generaly poor behaviour of rhododendrons is cultural, not
disease. A healthy rhododendron is very resistant to disease. There
are diseases that spread in the soil, but very few that are spread by
pruning.

The biggest cultural problems are walnut roots or leaves, high soil
temperatures, drought, too moist a soil and over watering, lack of iron
available in the soil and alkaline soil, improper planting and root
stangulation, wind damage, sunburn, fertilizer burn, herbicide burn,
salt burn, etc. Rhododendrons are very sodium sensative, so winter use
of sodium salts is very toxic to them. On the other hand potassium
salts are beneficial of not used in excess.


Thanks a lot for this response, Steve. I wonder why my
rhododendron has looked sick since it got pruned? Maybe it was
just coincidental....

--
Jean B., 12 miles west of Boston, Massachusetts, USA