I have an azalea in a large pot on the E. side of the house
(So. Calif coastal), that has turned chlorotic. I gave it
iron twice, but has had no effect; leaves still have that
tell-tale appearance.

Light, water and fertilizer are normal.

Any suggestions?

TIA

Persephone

Good question. I used tro think sulfur would adjust the pH.


Sincerely,
John A. Keslick, Jr.
Arborist
http://home.ccil.org/~treeman
and www.treedictionary.com
Beware of so-called tree experts who do not understand tree biology.
Storms, fires, floods, earthquakes, and volcanic eruptions keep reminding us
that we are not the boss.

Persephone wrote in message
...
I have an azalea in a large pot on the E. side of the house
(So. Calif coastal), that has turned chlorotic. I gave it
iron twice, but has had no effect; leaves still have that
tell-tale appearance.

Light, water and fertilizer are normal.

Any suggestions?

TIA

Persephone

Persephone wrote:

I have an azalea in a large pot on the E. side of the house
(So. Calif coastal), that has turned chlorotic. I gave it
iron twice, but has had no effect; leaves still have that
tell-tale appearance.

Chlorisis (yellowing of the leaves between green veins) is a symptom of
poor nutrition, but does not reveal the source. It is usually caused by
an iron deficiency. Many conditions can be responsible for an iron
deficiency. Poor drainage, planting too deeply, heavy soil with poor
aeration, insect or fungus damage in the root zone and lack of moisture
all induce chlorosis.

After these conditions are eliminated as possible causes, soil testing
is in order. Chlorosis can be caused by malnutrition caused by
alkalinity of the soil, potassium deficiency, calcium deficiency, iron
deficiency or magnesium deficiency. Iron is most readily available in
acidic soils between pH 4.5-6.0. When the soil pH is above 6.5, iron may
be present in adequate amounts, but is in an unusable form, due to an
excessive amount of calcium carbonate. This can occur when plants are
placed too close to cement foundations or walkways.

Soil amendments that acidify the soil, such as iron sulfate or sulfur,
are the best long term solution. DO NOT USE ALUMINUM SULFATE; IT KILLS
RHODODENDRONS AND AZALEAS. Foliar sprays of iron sulfate or chelated
iron can reduce symptoms. A combination of acidification with sulfur and
iron supplements such as chelated iron or iron sulfate will usually
treat this problem. Chlorosis caused by magnesium deficiency is
initially the same as iron, but progresses to form reddish purple
blotches and marginal leaf necrosis (browning of leaf edges). Epsom
salts are a good source of supplemental magnesium. Chlorosis can also be
caused by nitrogen toxicity (usually caused by nitrate fertilizers) or
other conditions that damage the roots such as root rot, severe cutting
of the roots, root weevils or root death caused by extreme amounts of
fertilizer. There is a tonic that remedies some cases of chlorosis.

Diane Pertson, Otter Point, Vancouver Island, found the following
"foolproof formula" for chlorotic leaves or a rhododendron that isn't
looking healthy:

Purchase a bag of Epsom Salts crystals (magnesium sulfate) (available
here in bulk at farm-and-feed outlets), about $4.00 for a 5 lb. bag -
and a bottle of FULLY Chelated Iron & Zinc (this is a very concentrated
liquid - the chelation means it is in a form that can be readily
absorbed by the plant), about $7.00 for 1 quart; In a one gallon
watering can, put in 2 Tbsp. of Epsom Salts crystals and 2 Tbsp. of Iron
and Zinc liquid - fill with warm water and stir to dissolve; Sprinkle
this over the rhododendron - by that I mean drench the leaves with the
solution and pour the remainder around the drip line of the root ball.

In 1-2 weeks, the leaves should be nice and green. You could repeat the
process at this time if the leaves aren't fully green.

This works even better if, a month before, you have sweetened the soil
by sprinkling a little Dolomite Lime on the roots. Very acidic soil can
prevent the roots from taking up nutrients. As many of my rhododendrons
are planted in very acidic soil under a canopy of giant cedar trees, I
find an application of Dolomite and a light topdressing of mushroom
manure in late spring is all they need.

If soil is too acid, the symptoms can be the same. Very acidic soil can
prevent the roots from taking up nutrients. In the western USA where
many rhododendrons are planted in very acidic forest soil, an
application of Dolomite and a light topdressing of mushroom manure in
late spring is all they need. Sprinkle the lime on in late winter, very
early spring. Don't overdo it - just a light sprinkle. If it is
mid-spring, get the lime on right away so the rhododendron roots will be
able to take up the soil nutrients in time for new growth. If you don't
have rain, water it in well.
--
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

On Sat, 14 Jul 2007 18:12:21 -0700, Persephone wrote:

I have an azalea in a large pot on the E. side of the house
(So. Calif coastal), that has turned chlorotic. I gave it
iron twice, but has had no effect; leaves still have that
tell-tale appearance.

Light, water and fertilizer are normal.

Any suggestions?

TIA

Persephone


Check for tiny mites/insect damage. If there is no sign here, give it
a half dose of acid fertilizer (such as Miracle Grow or a fertilizer
for azaleas). You should see results in 2-3 weeks.

Phisherman wrote:

Check for tiny mites/insect damage. If there is no sign here, give it
a half dose of acid fertilizer (such as Miracle Grow or a fertilizer
for azaleas). You should see results in 2-3 weeks.

Miracle Grow is more of a problem than a cure. It is very high in
nitrogen which is not what azaleas need. It is water soluble so it is
only a temporary measure designed to sell miracle grow. Hollytone is a
good organic slow release, long-lasting, fertilizer but I only recommend
using it once in the spring and at half the rate on the package.

--
Pardon my spam deterrent; send email to
Cheers, Steve Henning in Reading, PA USA
http://rhodyman.net

In addition, Miracle Grow claims they are selling you plant "food". That
is false advertisement. We do not feed trees. They are autotrophs.

Food is a substance that provides and energy source, mostly. Nutrient is a
substance that provides an energy source, elements, and other substances
essential for life, in types and amounts that can provide a healthy life.
Fertilizer is a substance that provides elements, as salts mostly, or in
bonded forms, that require microorganisms to alter to forms that can be
absorbed by plants. I do not call elements - nutrients, however nutrients
would contain elements. You can put a file in a folder but you can't put a
folder in a file. A list of elements can be found he
http://images.google.com/imgres?imgu...US211%26sa%3DX

17 Elements For Life - Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus,
Potassium, Calcium, Sulfur, Magnesium, Manganese, Iron, Copper, Boron,
Molybdenum, Chlorine, Zinc, Nickel [Sodium, Cobalt, Selenium?]

14 essential elements are obtained by trees from the soil. I do not have a
list of which ones they are.

Wood is the substrate of the base of the food web, the mycorrhizal fungi.
Mycorrhizae tend to be abundant in composted wood such as nurse logs. We
had great success at tree biology workshops finding mycorrhizae during dryer
times, in and about nurse logs. I believe, you don't have to agree with it,
please, just think. I think that by applying mulch as I recommend under
mulch here that you facilitate the mycorrhizae rather than just adding what
I believe you mean as humus, over a lawn. Not that its bad in any way,
adding humus i.e..

Mulching - http://home.ccil.org/~treeman/sub3.html
and
http://www.treedictionary.com/DICT2003/M/ Look up "Mulch"

Did I say - Mycorrhizae are organs that facilitate the absorption of
elements essential for healthy growth. Mycorrhizae resist the Demons Of D.
Mycorrhizae facilitate the absorption of elements. Demons of D are those
things that add up to the big D word DEATH. E.g., Depletion, disruption,
and dysfunction. Elements can be depleted. Disruption, you get hit my a
Mac truck. Dysfunction, some organ such as mycorrhizae may not function.


Major Elements C; H; N; O; P; K; S; Mg; Ni; Fe; Ca; Zn; Mo; Mn; B; Cl; Cu

There is the law of the minimum. It states the element that is deficient
the most, would be the determining factor in the health of the tree.

I think research would be wise in the search for the optimum fertility level
for trees.

I did some soil testing in the upper four inches of soil and from at and
about nurse logs in old growth forest which contain hemlocks and white
pines. And much more. Here is my average on my testing for the latter.
These where five test. 3 test sites where in Allegheny National
Forest(Hearts Content) Pennsylvania
and two where in Allegheny National Forest(Tionesta Scenic area)
Pennsylvania.
Results are in Pounds Per Acre PPA. AVAILABLE ELEMENTS
P 8.2
K 236
Mg 107
Ca 594
Al 220.6
Fe 110.8
Mn 118.6
Zn 11.96
NO3-N 28.8
Did not get B or CU.
Organic matter was 29.32%
Ex Acidity 81 ME/100G
Salts mmho: 0.01 mmho/cm
Moisture %3.97
Water Soluble mg/kg B 1.0738
ACID Soluble (mg/kg)
Cd 0.976
Cu 6.768
Ni 5.71 (Penn State discovered the element Ni to be essential in small
amounts)
Mn 426.378
Co 3.084
Zn 46.818
Pb 101.792
Cr 5.078
P 726.226
The CARBON TO NITROGEN RATION was 27:1
pH 4.2 WOW

That would be a goal of mine if I was going to provide essential elements
professionally. I did not see to many people in the old growth sections.

There was more calcium at a nurse logs in a separate test.

We don't feed trees, however, we can feed the soil with composted wood
(chips and nurse logs) and leaves. We can feed the system.

I have some results for some sick hemlocks (elements in soil)


--
Sincerely,
John A. Keslick, Jr.
Arborist
http://home.ccil.org/~treeman
and www.treedictionary.com
Beware of so-called tree experts who do not understand tree biology.
Storms, fires, floods, earthquakes, and volcanic eruptions keep reminding us
that we are not the boss.






"Stephen Henning" wrote in message
news
Phisherman wrote:

Check for tiny mites/insect damage. If there is no sign here, give it
a half dose of acid fertilizer (such as Miracle Grow or a fertilizer
for azaleas). You should see results in 2-3 weeks.

Miracle Grow is more of a problem than a cure. It is very high in
nitrogen which is not what azaleas need. It is water soluble so it is
only a temporary measure designed to sell miracle grow. Hollytone is a
good organic slow release, long-lasting, fertilizer but I only recommend
using it once in the spring and at half the rate on the package.

--
Pardon my spam deterrent; send email to
Cheers, Steve Henning in Reading, PA USA
http://rhodyman.net

On Sat, 14 Jul 2007 18:12:21 -0700, Persephone wrote:

I have an azalea in a large pot on the E. side of the house
(So. Calif coastal), that has turned chlorotic. I gave it
iron twice, but has had no effect; leaves still have that
tell-tale appearance.

Light, water and fertilizer are normal.

Any suggestions?

TIA

Persephone


FWIW, here's the reply I received from my local nursery:

Ironite is the right way to go, but if the roots do not get enough
oxygen to enable the plant to take in the trace elements (Iron,Zinc,
Manganese etc) it will not help. What I mean with enough Oxygen, is
that Azaleas could easily be planted too deep - they like to have the
root ball be exposed, so I would recommend scraping the top layer away
from the trunk and not keeping the soil soaked. A liquid fertilizer
sprayed on the leaves such as soil acidifier should rectify the
problem faster than if the nutrients were to be absorbed by the roots
and transferred to the leaves.

Persephone

Persephone wrote:

On Sat, 14 Jul 2007 18:12:21 -0700, Persephone wrote:

I have an azalea in a large pot on the E. side of the house
(So. Calif coastal), that has turned chlorotic. I gave it
iron twice, but has had no effect; leaves still have that
tell-tale appearance.

FWIW, here's the reply I received from my local nursery:
Ironite is the right way to go, but if the roots do not get enough
oxygen to enable the plant to take in the trace elements (Iron,Zinc,
Manganese etc) it will not help. What I mean with enough Oxygen, is
that Azaleas could easily be planted too deep - they like to have the
root ball be exposed, so I would recommend scraping the top layer away
from the trunk and not keeping the soil soaked. A liquid fertilizer
sprayed on the leaves such as soil acidifier should rectify the
problem faster than if the nutrients were to be absorbed by the roots
and transferred to the leaves.

There is some truth to what they are saying, but:

1) if the soil is not acidic, iron won't help. The soil must be acidic.
The soil must be made acidic. Powdered sulfur will do this.

2) if the soil is deficient in potassium, calcium, or magnesium it will
show the same symptoms but the iron won't help. Potash of Sulfur
(K2SO4), Gypsum (CaSO4), and Epsom salts (MgSO4) will address these
respectively if used in moderation.

3) if you have poor drainage the scraping the top layer of soil will
cause puddling and make the problem worse. Using a raised bed with good
acidic soil will address this problem.

4) if it isn't getting enough oxygen, it can be poor drainage and/or
being planted too deeply. Using a raised bed and not planting any
deeper than it was originally when purchased will solve both problems.

Unfortunately, most stores feed the customers desire to buy a product to
pour on the problem and solve it. That doesn't always work.
--
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

On Thu, 19 Jul 2007 15:29:04 -0400, Stephen Henning
wrote:

Persephone wrote:

On Sat, 14 Jul 2007 18:12:21 -0700, Persephone wrote:

I have an azalea in a large pot on the E. side of the house
(So. Calif coastal), that has turned chlorotic. I gave it
iron twice, but has had no effect; leaves still have that
tell-tale appearance.

FWIW, here's the reply I received from my local nursery:
Ironite is the right way to go, but if the roots do not get enough
oxygen to enable the plant to take in the trace elements (Iron,Zinc,
Manganese etc) it will not help. What I mean with enough Oxygen, is
that Azaleas could easily be planted too deep - they like to have the
root ball be exposed, so I would recommend scraping the top layer away
from the trunk and not keeping the soil soaked. A liquid fertilizer
sprayed on the leaves such as soil acidifier should rectify the
problem faster than if the nutrients were to be absorbed by the roots
and transferred to the leaves.

There is some truth to what they are saying, but:

1) if the soil is not acidic, iron won't help. The soil must be acidic.
The soil must be made acidic. Powdered sulfur will do this.

The soil in this area is adobe (basic), but the people before me
mulched regularly, as have I, so I suspectthat over many decades of
modification the PH has become either acidic, or at least neutral. I
should have it tested some time just out of curiousity, though I don't
usually have problems like this.

2) if the soil is deficient in potassium, calcium, or magnesium it will
show the same symptoms but the iron won't help. Potash of Sulfur
(K2SO4), Gypsum (CaSO4), and Epsom salts (MgSO4) will address these
respectively if used in moderation.

3) if you have poor drainage the scraping the top layer of soil will
cause puddling and make the problem worse. Using a raised bed with good
acidic soil will address this problem.

Good drainage in that large pot. Water doesn't puddle.

4) if it isn't getting enough oxygen, it can be poor drainage and/or
being planted too deeply. Using a raised bed and not planting any
deeper than it was originally when purchased will solve both problems.

I've scraped away some soil from the trunk; have refrained from
over-watering, and will pick up some powdered sulfur.

Unfortunately, most stores feed the customers desire to buy a product to
pour on the problem and solve it. That doesn't always work.

That's probably true, but the email from the nursery was not pushy.
I already have some Miracle-Gro; it probably won't kill the plant
to get a moderate application.

Stay tuned!

Persephone

Persephone wrote:

The soil in this area is adobe (basic), but the people before me
mulched regularly, as have I, so I suspectthat over many decades of
modification the PH has become either acidic, or at least neutral. I
should have it tested some time just out of curiousity, though I don't
usually have problems like this.

Neutral won't work. It must be acidic. A pH of 5 to 6.5 is necessary.

I already have some Miracle-Gro; it probably won't kill the plant
to get a moderate application.

Miracle-Gro does more harm than good. It is a soluble nitrogen
fertilizer. Your plant is stressed and feeding it nitrogen is not a
wise move. The iron and sulfur are the right approach. Usually in
alkaline soil such as yours the only easy way to grow azaleas is in a
raised bed. Then the alkalinity of the surrounding soil doesn't affect
the azaleas. The raised bed only needs to be 8" to 12" high. Then use
a good acidic garden soil. If you want to raise acid loving plants like
azaleas, you will have to meet them half way by providing acidic soil.
--
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

On Fri, 20 Jul 2007 16:53:55 -0400, Stephen Henning
wrote:

Persephone wrote:

The soil in this area is adobe (basic), but the people before me
mulched regularly, as have I, so I suspectthat over many decades of
modification the PH has become either acidic, or at least neutral. I
should have it tested some time just out of curiousity, though I don't
usually have problems like this.

Neutral won't work. It must be acidic. A pH of 5 to 6.5 is necessary.

I already have some Miracle-Gro; it probably won't kill the plant
to get a moderate application.

Miracle-Gro does more harm than good. It is a soluble nitrogen
fertilizer. Your plant is stressed and feeding it nitrogen is not a
wise move. The iron and sulfur are the right approach. Usually in
alkaline soil such as yours the only easy way to grow azaleas is in a
raised bed.

What about a large pot where soil can be modified?

Then the alkalinity of the surrounding soil doesn't affect
the azaleas. The raised bed only needs to be 8" to 12" high. Then use
a good acidic garden soil. If you want to raise acid loving plants like
azaleas, you will have to meet them half way by providing acidic soil.

OK, suggestions assimilated.

I have had azaleas in that large pot on the E. side of the house
before; they bloomed magnificently, but it's true they only produced
for about 3-4 seasons.

I'll get some sulfur and see if it will work with the previously
applied iron.

Persephone

On Fri, 20 Jul 2007 15:20:35 -0700, Persephone wrote:

I have had azaleas in that large pot on the E. side of the house
before; they bloomed magnificently, but it's true they only produced
for about 3-4 seasons.

I'll get some sulfur and see if it will work with the previously
applied iron.

Persephone

Where do you live, Persephone, I forget. If it is in a place with
very hot summers it will be extremely difficult keeping azalea's
healthy unless you have naturally occurring acidic soil.

In Dallas there is a strip of very acidic soil running through the
center of town in the city. They have huge azalea's there which are
healthy, vibrant and huge. They thrive through the heat because the
soil is naturally acidic.

Just some added info to what Stephen already told you.

V

Persephone wrote:

What about a large pot where soil can be modified?

Usually they do best with a double pot with drainage holes in both pots.
The outer pot is to protect the inner pot from the sun. Direct sun on
the pot of an azalea can be bad, especially if the pot is not white.
Even potted azaleas do better when the pot is sunk in the soil to help
maintain even root temperatures and more even moisture. In the winter
in colder climates the pots must be protected from freezing.
--
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

On Sat, 21 Jul 2007 07:14:31 -0500, jangchub
wrote:

On Fri, 20 Jul 2007 15:20:35 -0700, Persephone wrote:

I have had azaleas in that large pot on the E. side of the house
before; they bloomed magnificently, but it's true they only produced
for about 3-4 seasons.

I'll get some sulfur and see if it will work with the previously
applied iron.

Persephone

Where do you live, Persephone, I forget. If it is in a place with
very hot summers it will be extremely difficult keeping azalea's
healthy unless you have naturally occurring acidic soil.

I live in Santa Monica CA, near the beach. It's always 10-20 degrees
cooler than inland. We don't have hot summers. Ours is a near-ideal
Mediterranean climate -- never too hot, never too cold. ('cept we're
in our 2nd year of drought; had only 1 decent rain all last winter,
plus a few chicken-shit showers). So -- lots of irrigating, or switch
to xeriscapic which I'm considering.

In Dallas there is a strip of very acidic soil running through the
center of town in the city. They have huge azaleas there which are
healthy, vibrant and huge. They thrive through the heat because the
soil is naturally acidic.

Just some added info to what Stephen already told you.

OK, I got some sulfur today - was going to email him to see if it
was the right kind, but Stephen, I hope you're seeing this?
Product is called "Sulfur Dust", by Lilly Miller. 90% sulfur, 10%
inert ingredients.

What's confusing to me is that it's sold as a fungicide/insecticide.
"For use on roses, grapes, citrus fruits, berries,nuts, vegetables,
flowers, shrubs, trees. Controls powdery mildew, rust, scab, mites."

Doesn't say anything about acidifying the soil. Only mention of
flowers is dusting or spraying foliage.

They said I could return it if it wasn't the right thing.

So -- can I in fact mix this with the soil of the azalea?

Or spray its foliage?

If this is the wrong product, could you describe the right one?

I know many on this NG are hostile to Miracle-Gro-type products, but
they do make an acid fertilizer which I've never used. Is this
something to consider?

TIA to all

Persephne.

In article , Persephone
wrote:

On Sat, 21 Jul 2007 07:14:31 -0500, jangchub
wrote:

On Fri, 20 Jul 2007 15:20:35 -0700, Persephone wrote:

I have had azaleas in that large pot on the E. side of the house
before; they bloomed magnificently, but it's true they only produced
for about 3-4 seasons.

I'll get some sulfur and see if it will work with the previously
applied iron.

Persephone

Where do you live, Persephone, I forget. If it is in a place with
very hot summers it will be extremely difficult keeping azalea's
healthy unless you have naturally occurring acidic soil.

I live in Santa Monica CA, near the beach. It's always 10-20 degrees
cooler than inland. We don't have hot summers. Ours is a near-ideal
Mediterranean climate -- never too hot, never too cold. ('cept we're
in our 2nd year of drought; had only 1 decent rain all last winter,
plus a few chicken-shit showers). So -- lots of irrigating, or switch
to xeriscapic which I'm considering.

In Dallas there is a strip of very acidic soil running through the
center of town in the city. They have huge azaleas there which are
healthy, vibrant and huge. They thrive through the heat because the
soil is naturally acidic.

Just some added info to what Stephen already told you.

OK, I got some sulfur today - was going to email him to see if it
was the right kind, but Stephen, I hope you're seeing this?
Product is called "Sulfur Dust", by Lilly Miller. 90% sulfur, 10%
inert ingredients.

What's confusing to me is that it's sold as a fungicide/insecticide.
"For use on roses, grapes, citrus fruits, berries,nuts, vegetables,
flowers, shrubs, trees. Controls powdery mildew, rust, scab, mites."

Doesn't say anything about acidifying the soil. Only mention of
flowers is dusting or spraying foliage.

They said I could return it if it wasn't the right thing.

So -- can I in fact mix this with the soil of the azalea?

Or spray its foliage?

If this is the wrong product, could you describe the right one?

I know many on this NG are hostile to Miracle-Gro-type products, but
they do make an acid fertilizer which I've never used. Is this
something to consider?

TIA to all

Persephne.

Wake up dumb bunny and google "elemental sulfur, soil pH". Why are you
wasting our time?
--
Billy
http://angryarab.blogspot.com/