[Stephen Henning]

"dwight" wrote:

As an aside, I bought three rhodos early this spring, popped them in the
ground. They flowered spectacularly, sprouted new growth, and today all
three are flat-out dead. Perhaps planting them along my pine walk was a bad
idea?

Hi Dwight,

Actually I got my SX10IS for photographing rhododendrons and travel
photography. Too bad your rhodies died.

There are a number of possibilities:

ROOT STRANGULATION: This is best prevented by proper root pruning when
planting. The roots need to be opened up. Whether the plant is
balled-and-burlaped or potted, make sure that the plant is getting wet.
Rhododendron guru Harold Greer noted: "Quite often a plant will get
completely dry and then no matter how much water you apply, the rootball
will just keep shedding it. The top of the soil may seem wet, and the
soil around the plant may even be very wet, but the actual rootball of
the plant is bone dry. This is especially true for newly planted
rhododendrons, and it is the major reason for failure, or at least less
than great success with that new plant. It is hard to believe that a
plant can be within mere inches of a sprinkler that has been running for
hours and still be dry, yet it can be SO TRUE!"

DROUGHT: Drought can cause entire entire plants to die. We have had
several years of drought here and we observe that if rhododendrons and
azaleas are not watered during a drought some plants will die,
especially ones just planted. Never let the soil completely dry out'
it's best to keep the soil evenly moist. Too much water or poorly
drained soil might be another explanation of sudden rhododendron or
azalea death. Rhododendrons and azaleas have very fine, fibrous roots
that are easily damaged by waterlogging, even for short periods of time.

VOLES: Voles, also known as meadow mice, may have chewed on the bark
and roots near the crown of the plant. Sometimes they chew all the way
around the trunk and kill the inner bark, resulting in death of the
whole plant. Keep mulch away from the trunk to discourage voles.

JUGLONE POISONING: The roots of Black Walnut (Juglans nigra L.) and
Butternut (Juglans cinerea L.) produce a substance known as juglone
(5-hydroxy-alphanapthaquinone). Persian (English or Carpathian) walnut
trees are sometimes grafted onto black walnut rootstocks. Many plants
such as tomato, potato, blackberry, blueberry, azalea, mountain laurel,
rhododendron, red pine and apple may be injured or killed within one to
two months of growth within the root zone of these trees. The toxic zone
from a mature tree occurs on average in a 50 to 60 foot radius from the
trunk, but can be up to 80 feet. The area affected extends outward each
year as a tree enlarges. Young trees two to eight feet high can have a
root diameter twice the height of the top of the tree, with susceptible
plants dead within the root zone and dying at the margins. The juglone
toxin occurs in the leaves, bark and wood of walnut, but these contain
lower concentrations than in the roots. Juglone is poorly soluble in
water and does not move very far in the soil.

ROOT ROT: Phytophthora Root Rot or wilt is the major killer of
rhododendrons and azaleas. It develops when roots are growing in wet
conditions. The rot is more prevalent in warm summer conditions. Plants
infected with crown rot caused by the fungi Phytophthora have roots
which become clogged with brown fungi internally. The roots get blocked
and the plant wilts and dies. There is not much of any cure for crown
rot. Some varieties of rhododendrons are vulnerable (Chionoides,
Catawbiense Album, Nova Zembla) and some are resistant (Roseum Elegans,
Scintillation, PJM). Sphagnum moss and bark dust combined with good
drainage seem to prevent crown rot, but do not cure it.

There are two essential when growing rhododendrons:

DRAINAGE: Because the fine roots of azaleas and rhododendrons are
easily blocked by fungi, excellent drainage is important. To test
drainage, dig a hole 6 inches deep in the bed and fill it with water. If
the water has not drained from the hole in four hours, install drainage
tile to carry away excess water, or build raised beds. Moist
well-drained soil is a must for most varieties. This sounds difficult,
but it means to not let the soil dry out completely but don't get it too
wet. Thoroughly water if necessary and then let it become almost dry.
Most gardeners do this by planting in a well-drained area and mulching
to hold the soil moisture in. Watering is seldom necessary except during
long dry periods.

ACID SOIL: Most varieties require an acidic soil (pH 4.5-6). Powdered
sulfur is the best agent to acidify the soil. Holly-tone has this in it.
Your plants will get chlorotic if the soil is not acidic enough.
Chlorosis is easily identified; the leaves turn yellow with green veins.
--
Pardon my spam deterrent; send email to
Visit my Rhododendron and Azalea web pages at:
http://rhodyman.net/rahome.html
Also visit the Rhododendron and Azalea Bookstore at:
http://rhodyman.net/rabooks.html
Cheers, Steve Henning in Reading, PA USA Zone 6

[paghat[_2_]]

Nice overview on causes of sudden rhody death for newly planted shrubs.
I'd never heard that about voles being a possible threat to shrubs in the
average garden, though I know of an orchard that had girdling by mice or
voles of all the trees after the owner dynamited a winter rattlesnake den
resulting in overpopulation and food shortage. Wouldn't've happened
otherwise. So it served the guy right.

If you turn this overview into a web article you might want to add one
more thing: death by deep woodchip/shaving mulch. In the early days of the
Rhody Species Foundation they used woodchip mulch and decades later
they're still having to repair some of the soil sights because of that
initial error. It held moisture above the soil so that shrubs didn't get
proper moisture, and it smothered roots. When they moved the collection
from Oregon to the Weyerhaueser site, the mulch was totally free because
hey it was Weyhrhaueser. So hundreds of important specimens dried out &
died due to the woodchip shavings. I've an ongoing landscaping job at a
property that used woodchips four inches to a foot deep and I expect never
to repair all that damage, it'd take a tractor and sacrificing everything
that's managed to survive.

-paggers

In article , Stephen
Henning wrote:

"dwight" wrote:

As an aside, I bought three rhodos early this spring, popped them in the
ground. They flowered spectacularly, sprouted new growth, and today all
three are flat-out dead. Perhaps planting them along my pine walk was a bad
idea?

Hi Dwight,

Actually I got my SX10IS for photographing rhododendrons and travel
photography. Too bad your rhodies died.

There are a number of possibilities:

ROOT STRANGULATION: This is best prevented by proper root pruning when
planting. The roots need to be opened up. Whether the plant is
balled-and-burlaped or potted, make sure that the plant is getting wet.
Rhododendron guru Harold Greer noted: "Quite often a plant will get
completely dry and then no matter how much water you apply, the rootball
will just keep shedding it. The top of the soil may seem wet, and the
soil around the plant may even be very wet, but the actual rootball of
the plant is bone dry. This is especially true for newly planted
rhododendrons, and it is the major reason for failure, or at least less
than great success with that new plant. It is hard to believe that a
plant can be within mere inches of a sprinkler that has been running for
hours and still be dry, yet it can be SO TRUE!"

DROUGHT: Drought can cause entire entire plants to die. We have had
several years of drought here and we observe that if rhododendrons and
azaleas are not watered during a drought some plants will die,
especially ones just planted. Never let the soil completely dry out'
it's best to keep the soil evenly moist. Too much water or poorly
drained soil might be another explanation of sudden rhododendron or
azalea death. Rhododendrons and azaleas have very fine, fibrous roots
that are easily damaged by waterlogging, even for short periods of time.

VOLES: Voles, also known as meadow mice, may have chewed on the bark
and roots near the crown of the plant. Sometimes they chew all the way
around the trunk and kill the inner bark, resulting in death of the
whole plant. Keep mulch away from the trunk to discourage voles.

JUGLONE POISONING: The roots of Black Walnut (Juglans nigra L.) and
Butternut (Juglans cinerea L.) produce a substance known as juglone
(5-hydroxy-alphanapthaquinone). Persian (English or Carpathian) walnut
trees are sometimes grafted onto black walnut rootstocks. Many plants
such as tomato, potato, blackberry, blueberry, azalea, mountain laurel,
rhododendron, red pine and apple may be injured or killed within one to
two months of growth within the root zone of these trees. The toxic zone
from a mature tree occurs on average in a 50 to 60 foot radius from the
trunk, but can be up to 80 feet. The area affected extends outward each
year as a tree enlarges. Young trees two to eight feet high can have a
root diameter twice the height of the top of the tree, with susceptible
plants dead within the root zone and dying at the margins. The juglone
toxin occurs in the leaves, bark and wood of walnut, but these contain
lower concentrations than in the roots. Juglone is poorly soluble in
water and does not move very far in the soil.

ROOT ROT: Phytophthora Root Rot or wilt is the major killer of
rhododendrons and azaleas. It develops when roots are growing in wet
conditions. The rot is more prevalent in warm summer conditions. Plants
infected with crown rot caused by the fungi Phytophthora have roots
which become clogged with brown fungi internally. The roots get blocked
and the plant wilts and dies. There is not much of any cure for crown
rot. Some varieties of rhododendrons are vulnerable (Chionoides,
Catawbiense Album, Nova Zembla) and some are resistant (Roseum Elegans,
Scintillation, PJM). Sphagnum moss and bark dust combined with good
drainage seem to prevent crown rot, but do not cure it.

There are two essential when growing rhododendrons:

DRAINAGE: Because the fine roots of azaleas and rhododendrons are
easily blocked by fungi, excellent drainage is important. To test
drainage, dig a hole 6 inches deep in the bed and fill it with water. If
the water has not drained from the hole in four hours, install drainage
tile to carry away excess water, or build raised beds. Moist
well-drained soil is a must for most varieties. This sounds difficult,
but it means to not let the soil dry out completely but don't get it too
wet. Thoroughly water if necessary and then let it become almost dry.
Most gardeners do this by planting in a well-drained area and mulching
to hold the soil moisture in. Watering is seldom necessary except during
long dry periods.

ACID SOIL: Most varieties require an acidic soil (pH 4.5-6). Powdered
sulfur is the best agent to acidify the soil. Holly-tone has this in it.
Your plants will get chlorotic if the soil is not acidic enough.
Chlorosis is easily identified; the leaves turn yellow with green veins.
--
visit my temperate gardening website:
http://www.paghat.com
visit my film reviews website:
http://www.weirdwildrealm.com

[Bill[_13_]]

In article ,
(paghat) wrote:

Nice overview on causes of sudden rhody death for newly planted shrubs.
I'd never heard that about voles being a possible threat to shrubs in the
average garden, though I know of an orchard that had girdling by mice or
voles of all the trees after the owner dynamited a winter rattlesnake den
resulting in overpopulation and food shortage. Wouldn't've happened
otherwise. So it served the guy right.

If you turn this overview into a web article you might want to add one
more thing: death by deep woodchip/shaving mulch. In the early days of the
Rhody Species Foundation they used woodchip mulch and decades later
they're still having to repair some of the soil sights because of that
initial error. It held moisture above the soil so that shrubs didn't get
proper moisture, and it smothered roots. When they moved the collection
from Oregon to the Weyerhaueser site, the mulch was totally free because
hey it was Weyhrhaueser. So hundreds of important specimens dried out &
died due to the woodchip shavings. I've an ongoing landscaping job at a
property that used woodchips four inches to a foot deep and I expect never
to repair all that damage, it'd take a tractor and sacrificing everything
that's managed to survive.

-paggers

In article , Stephen
Henning wrote:

"dwight" wrote:

As an aside, I bought three rhodos early this spring, popped them in the
ground. They flowered spectacularly, sprouted new growth, and today all
three are flat-out dead. Perhaps planting them along my pine walk was a
bad
idea?

Hi Dwight,

Actually I got my SX10IS for photographing rhododendrons and travel
photography. Too bad your rhodies died.

There are a number of possibilities:

ROOT STRANGULATION: This is best prevented by proper root pruning when
planting. The roots need to be opened up. Whether the plant is
balled-and-burlaped or potted, make sure that the plant is getting wet.
Rhododendron guru Harold Greer noted: "Quite often a plant will get
completely dry and then no matter how much water you apply, the rootball
will just keep shedding it. The top of the soil may seem wet, and the
soil around the plant may even be very wet, but the actual rootball of
the plant is bone dry. This is especially true for newly planted
rhododendrons, and it is the major reason for failure, or at least less
than great success with that new plant. It is hard to believe that a
plant can be within mere inches of a sprinkler that has been running for
hours and still be dry, yet it can be SO TRUE!"

DROUGHT: Drought can cause entire entire plants to die. We have had
several years of drought here and we observe that if rhododendrons and
azaleas are not watered during a drought some plants will die,
especially ones just planted. Never let the soil completely dry out'
it's best to keep the soil evenly moist. Too much water or poorly
drained soil might be another explanation of sudden rhododendron or
azalea death. Rhododendrons and azaleas have very fine, fibrous roots
that are easily damaged by waterlogging, even for short periods of time.

VOLES: Voles, also known as meadow mice, may have chewed on the bark
and roots near the crown of the plant. Sometimes they chew all the way
around the trunk and kill the inner bark, resulting in death of the
whole plant. Keep mulch away from the trunk to discourage voles.

JUGLONE POISONING: The roots of Black Walnut (Juglans nigra L.) and
Butternut (Juglans cinerea L.) produce a substance known as juglone
(5-hydroxy-alphanapthaquinone). Persian (English or Carpathian) walnut
trees are sometimes grafted onto black walnut rootstocks. Many plants
such as tomato, potato, blackberry, blueberry, azalea, mountain laurel,
rhododendron, red pine and apple may be injured or killed within one to
two months of growth within the root zone of these trees. The toxic zone
from a mature tree occurs on average in a 50 to 60 foot radius from the
trunk, but can be up to 80 feet. The area affected extends outward each
year as a tree enlarges. Young trees two to eight feet high can have a
root diameter twice the height of the top of the tree, with susceptible
plants dead within the root zone and dying at the margins. The juglone
toxin occurs in the leaves, bark and wood of walnut, but these contain
lower concentrations than in the roots. Juglone is poorly soluble in
water and does not move very far in the soil.

ROOT ROT: Phytophthora Root Rot or wilt is the major killer of
rhododendrons and azaleas. It develops when roots are growing in wet
conditions. The rot is more prevalent in warm summer conditions. Plants
infected with crown rot caused by the fungi Phytophthora have roots
which become clogged with brown fungi internally. The roots get blocked
and the plant wilts and dies. There is not much of any cure for crown
rot. Some varieties of rhododendrons are vulnerable (Chionoides,
Catawbiense Album, Nova Zembla) and some are resistant (Roseum Elegans,
Scintillation, PJM). Sphagnum moss and bark dust combined with good
drainage seem to prevent crown rot, but do not cure it.

There are two essential when growing rhododendrons:

DRAINAGE: Because the fine roots of azaleas and rhododendrons are
easily blocked by fungi, excellent drainage is important. To test
drainage, dig a hole 6 inches deep in the bed and fill it with water. If
the water has not drained from the hole in four hours, install drainage
tile to carry away excess water, or build raised beds. Moist
well-drained soil is a must for most varieties. This sounds difficult,
but it means to not let the soil dry out completely but don't get it too
wet. Thoroughly water if necessary and then let it become almost dry.
Most gardeners do this by planting in a well-drained area and mulching
to hold the soil moisture in. Watering is seldom necessary except during
long dry periods.

ACID SOIL: Most varieties require an acidic soil (pH 4.5-6). Powdered
sulfur is the best agent to acidify the soil. Holly-tone has this in it.
Your plants will get chlorotic if the soil is not acidic enough.
Chlorosis is easily identified; the leaves turn yellow with green veins.

Found this and thought mimicking the environment of Tibet may matter.

³There are altogether 400 species of rhododendron on the Tibetan
Plateau, which make up about 50 percent of the world¹s total species.
According to Wu and Feng (1992)²

From the exiled Government of Tibet

http://www.tibet.com/eco/intro.html

Think of all the plant hunters of the early 1900¹s and where they
collected plants. The name Weston comes to mind but I may be confused
with Edward Weston. Perhaps the camera reference led me astray.

Bill

--
Garden in shade zone 5 S Jersey USA

Fight TB http://xdrtb.org/

[Stephen Henning]

(paghat) wrote:

Nice overview on causes of sudden rhody death for newly planted shrubs.
I'd never heard that about voles being a possible threat to shrubs in the
average garden, though I know of an orchard that had girdling by mice or
voles of all the trees after the owner dynamited a winter rattlesnake den
resulting in overpopulation and food shortage. Wouldn't've happened
otherwise. So it served the guy right.

If you turn this overview into a web article you might want to add one
more thing: death by deep woodchip/shaving mulch. In the early days of the
Rhody Species Foundation they used woodchip mulch and decades later
they're still having to repair some of the soil sights because of that
initial error. It held moisture above the soil so that shrubs didn't get
proper moisture, and it smothered roots. When they moved the collection
from Oregon to the Weyerhaueser site, the mulch was totally free because
hey it was Weyhrhaueser. So hundreds of important specimens dried out &
died due to the woodchip shavings. I've an ongoing landscaping job at a
property that used woodchips four inches to a foot deep and I expect never
to repair all that damage, it'd take a tractor and sacrificing everything
that's managed to survive.

Hi Paghat,

I run into your website all of the time. Great site. My response was
taken from my website. I am familiar with what you are talking about.
I was visiting the RSF when they were moving some very large rhodies
trying to remedy the problem you mention. We have a friend, John
Doppel, the hybridizes a lot and grows his transplants in soil mulched
with local hardwood saw dust from a local factory that makes wooden
spoons. He has absolutely no problem with the small plants, but finds
that thire roots end up growing in the sawdust. Then, when the sawdust
rots, the roots are in this slime. His tactic is to transplant them
before this happens. On his larger plants he doesn't seem to use the
saw dust like he does with the liners.

Conventional wisdom is to not use saw dust around rhodies because it
consumes all of the nitrogen leaving the plants malnourished, but John's
experience runs counter to conventional wisdom. He has no nutrient
problems at all.

Regarding the voles, the vole damage is especially bad if people mulch
around the trunks of their rhododendrons. The voles tunnel under the
mulch and run into the trunks in the winter and have dinner. If the
mulch is away from the trunks, it keeps the voles away in the middle of
winter.
--
Pardon my spam deterrent; send email to
Visit my Rhododendron and Azalea web pages at:
http://rhodyman.net/rahome.html
Also visit the Rhododendron and Azalea Bookstore at:
http://rhodyman.net/rabooks.html
Cheers, Steve Henning in Reading, PA USA Zone 6

[Stephen Henning]

Hi Bill,

In the wild most rhododendron varieties grow in the high Himalayas as
saprophytes and parasites in trees. Many are not even found growing in
the ground.

Over 1000 different varieties of rhododendrons and azaleas are found in
the wild in China, Tibet, Nepal, India, Korea, Taiwan, Japan, Australia,
New Guinea, Borneo and North America. Very few of these can be grown in
the US. The rhododendron species foundation in Federal Way, WA, has
about 400 different subspecies representing 200 different species.

Peter John Mezitt hybridized PJM and other rhododendrons in
Massachusetts at Weston Nurseries. The name Weston comes from Weston,
Massachusetts, not a plant explorer.

The most famous early rhododendron explorers we

John Fraser, a Scotsman that searched for plants in North America

Sir Joseph Hooker, a Scotsman that searched for plant in the Himalayas.

Robert Fortune, a Scotsman that searched for plants in China.

Ernest Henry, an Englishman that searched for plants in China.

George Forest, a Scotsman that searched for plants in China and Tibet.

Frank Kingdon Ward, a Englishman that searched for plants in the
Himalayas, Tibet, China, Burma and India.

Frank Ludlow and George Sherriff, Englishmen who searched for plants in
the Himalayas and Tibet.

New varieties of rhododendron are still being found in Nepal, China,
Borneo, New Guinea and the USA.

Although there are over 1000 rhododendron species, there are about
30,000 hybrid varieties that are registered and perhaps an equal number
that aren't registered. Many of these hybrids would not grow in the
Tibetan Plateau.

Bill wrote:

Found this and thought mimicking the environment of Tibet may matter.

³There are altogether 400 species of rhododendron on the Tibetan
Plateau, which make up about 50 percent of the world¹s total species.
According to Wu and Feng (1992)²

From the exiled Government of Tibet

http://www.tibet.com/eco/intro.html

Think of all the plant hunters of the early 1900¹s and where they
collected plants. The name Weston comes to mind but I may be confused
with Edward Weston. Perhaps the camera reference led me astray.

Bill

--
Garden in shade zone 5 S Jersey USA

Fight TB http://xdrtb.org/
--
Pardon my spam deterrent; send email to
Visit my Rhododendron and Azalea web pages at:
http://rhodyman.net/rahome.html
Also visit the Rhododendron and Azalea Bookstore at:
http://rhodyman.net/rabooks.html
Cheers, Steve Henning in Reading, PA USA Zone 6