I have been using Medicap Fe trunk implants very successfully to fight
iron chlorosis in my many pin oak trees for 15 years. Soil samples
show my pH to be 7.3 minimum and 7.6 near our long concrete cement
driveway. The soil report recommendation is to add 32 pounds of
sulphur (sulfur) to a depth of 12 inches per 1000 square feet (or 8
pounds to a 3 inch depth). Several internet sources recommend putting
the sulphur in approx. 12 inch deep holes in a 2 foot by 2 foot grid
around the tree. They also suggest a 1 to 1 ratio of sulphur and iron
sulfate (ferrous sulphate/copperas) to add iron in addition to
lowering the pH.
Question 1: Will the localized high sulphur concentrations do harm to
the trees?
Question 2: What is the highest sulphur application rate for grass
(lawn) (bluegrass and fescue) without damaging it?

On 10/18/2007 3:17 PM, wrote:
I have been using Medicap Fe trunk implants very successfully to fight
iron chlorosis in my many pin oak trees for 15 years. Soil samples
show my pH to be 7.3 minimum and 7.6 near our long concrete cement
driveway. The soil report recommendation is to add 32 pounds of
sulphur (sulfur) to a depth of 12 inches per 1000 square feet (or 8
pounds to a 3 inch depth). Several internet sources recommend putting
the sulphur in approx. 12 inch deep holes in a 2 foot by 2 foot grid
around the tree. They also suggest a 1 to 1 ratio of sulphur and iron
sulfate (ferrous sulphate/copperas) to add iron in addition to
lowering the pH.
Question 1: Will the localized high sulphur concentrations do harm to
the trees?
Question 2: What is the highest sulphur application rate for grass
(lawn) (bluegrass and fescue) without damaging it?


To acidify your soil, the sulfur must be converted into sulfuric acid by
soil bacteria. This happens slowly. For best results, make several
light applications repeatedly instead of applying the entire amount all
at once. This will help prevent killing the beneficial soil fungi since
sulfur is a natural fungicide. It helps if there is a good leaf mulch
that has started to decompose into leaf mold. (Oaks really need this in
their root zone.) Then the sulfuric acid will be formed on the soil
surface, and you won't have to dig. (Digging in the root zone of an oak
can kill the tree.)

You should also add some gypsum (calcium sulfate). A significant amount
can be added without the damage that might be caused by a significant
amount of elemental sulfur.

In the end, you will find that it takes more work and time to acidify an
alkaline soil than it takes to neutralize an acidic soil.

By the way, in my area, native oaks thrive in the native soil, which
tends to be alkaline. However, pin oaks (Quercus palustris) are native
to the eastern U.S. where many soils are indeed acidic, not California.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/

One of the problems with lowering the pH with sulfur is that the soil will
revert back.
Something that may interest you. I did a few soil studies on my own in old
growth forest. We tested for many essential elements and pH. In a old
growth forest which contained white pine and hemlock we got a pH average of
4.2 in the upper four inches of soil. This sample was taken from
Pennsylvania with the approval of the US Forest Service. I took the samples
in the area of soil where the mycorrhizae and rhizoplane was. Not inside
the rhizoplane. I understand that it is very difficult to get samples
actually from the rhizoplane. That is really where the samples should come
from because you will get different results there. As far as turf goes, it
likes high pH. Properly applying mulch could greatly help your situation.
Correct Mulching "suggestion". See "proper mulching".
http://home.ccil.org/~treeman/sub3.html

Two well written articles on soil chemistry and such are he
http://home.ccil.org/~treeman/shigo/RHIZO.html

http://home.ccil.org/~treeman/shigo/CHEM.html


[The soil report recommendation is to add 32 pounds of
sulphur (sulfur) to a depth of 12 inches per 1000 square feet (or 8
pounds to a 3 inch depth).]

The rhizoplane and rhizosphere where the absorption takes place, is usually
in the upper four inches of soil. There is no way I would put the sulfur
12" deep. I would think it would move downward rather then upward.
Actually I would


Several internet sources recommend putting
the sulphur in approx. 12 inch deep holes in a 2 foot by 2 foot grid
around the tree. They also suggest a 1 to 1 ratio of sulphur and iron
sulfate (ferrous sulphate/copperas) to add iron in addition to
lowering the pH.
Question 1: Will the localized high sulphur concentrations do harm to
the trees?
Question 2: What is the highest sulphur application rate for grass
(lawn) (bluegrass and fescue) without damaging it?

"symplastless" wrote in message
. ..
One of the problems with lowering the pH with sulfur is that the soil will
revert back.
Something that may interest you. I did a few soil studies on my own in
old growth forest. We tested for many essential elements and pH. In a
old growth forest which contained white pine and hemlock we got a pH
average of 4.2 in the upper four inches of soil. This sample was taken
from Pennsylvania with the approval of the US Forest Service. I took the
samples in the area of soil where the mycorrhizae and rhizoplane was.
Not inside the rhizoplane. I understand that it is very difficult to get
samples actually from the rhizoplane. That is really where the samples
should come from because you will get different results there. As far as
turf goes, it likes high pH. Properly applying mulch could greatly help
your situation.
Correct Mulching "suggestion". See "proper mulching".
http://home.ccil.org/~treeman/sub3.html

Two well written articles on soil chemistry and such are he
http://home.ccil.org/~treeman/shigo/RHIZO.html

http://home.ccil.org/~treeman/shigo/CHEM.html


[The soil report recommendation is to add 32 pounds of
sulphur (sulfur) to a depth of 12 inches per 1000 square feet (or 8
pounds to a 3 inch depth).]

The rhizoplane and rhizosphere where the absorption takes place, is
usually in the upper four inches of soil. There is no way I would put the
sulfur 12" deep. I would think it would move downward rather then upward.
Actually I would


Several internet sources recommend putting
the sulphur in approx. 12 inch deep holes in a 2 foot by 2 foot grid
around the tree. They also suggest a 1 to 1 ratio of sulphur and iron
sulfate (ferrous sulphate/copperas) to add iron in addition to
lowering the pH.
Question 1: Will the localized high sulphur concentrations do harm to
the trees?
Question 2: What is the highest sulphur application rate for grass
(lawn) (bluegrass and fescue) without damaging it?




I have a well. From which the well pump draws water. In this water is much
diluted hydrogen sulfide gas. To reduce this gas significantly, I use a
aerator bottle. The bottle then carries a significant amount of diluted
sulphuric acid. Every 24 hours by a timer, the bottle is flushed with the
same water. Total flush amount is 35 gallons. The ingredients go to a
french drain consisting of limestone rock of all different sizes. The drain
area is 10' wide X 10' long X 8' deep. The french drain is uphill from
several live oaks in the yard proper. During heavy rain periods, above the
french drain, the St. Augustine is very spongy when walking on it. Has been
this way for 2 years now.

Its obvious to me the live oaks immediately downhill from this french drain
are getting various amounts of, and various concentrations of H2SO4
(sulfuric acid). Yet, appear no different than other live oaks growing wild
in the surrounding area. The closest live oak has its trunk within 15 ft of
the french drain boundary on the downhill side from the french drain.

Native surface soil is nil to insignificant. Surface soil is generally a
gray clay that is always very quick to dry. Subsurface is fractured
limestone and caliche.

Is this addition of diluted sulphuric acid detrimental or aiding to the soil
and subsurface soil, or the live oaks themselves?
Dave

I think you said it when you said "The ingredients go to a french drain
consisting of LIMESTONE rock of all different sizes." The acid eats the
limestone and neutralizes it. Hence no change in the pin oaks.

"Dave" wrote in message
...
"symplastless" wrote in message
. ..
One of the problems with lowering the pH with sulfur is that the soil
will revert back.
Something that may interest you. I did a few soil studies on my own in
old growth forest. We tested for many essential elements and pH. In a
old growth forest which contained white pine and hemlock we got a pH
average of 4.2 in the upper four inches of soil. This sample was taken
from Pennsylvania with the approval of the US Forest Service. I took the
samples in the area of soil where the mycorrhizae and rhizoplane was.
Not inside the rhizoplane. I understand that it is very difficult to get
samples actually from the rhizoplane. That is really where the samples
should come from because you will get different results there. As far as
turf goes, it likes high pH. Properly applying mulch could greatly help
your situation.
Correct Mulching "suggestion". See "proper mulching".
http://home.ccil.org/~treeman/sub3.html

Two well written articles on soil chemistry and such are he
http://home.ccil.org/~treeman/shigo/RHIZO.html

http://home.ccil.org/~treeman/shigo/CHEM.html


[The soil report recommendation is to add 32 pounds of
sulphur (sulfur) to a depth of 12 inches per 1000 square feet (or 8
pounds to a 3 inch depth).]

The rhizoplane and rhizosphere where the absorption takes place, is
usually in the upper four inches of soil. There is no way I would put
the sulfur 12" deep. I would think it would move downward rather then
upward. Actually I would


Several internet sources recommend putting
the sulphur in approx. 12 inch deep holes in a 2 foot by 2 foot grid
around the tree. They also suggest a 1 to 1 ratio of sulphur and iron
sulfate (ferrous sulphate/copperas) to add iron in addition to
lowering the pH.
Question 1: Will the localized high sulphur concentrations do harm to
the trees?
Question 2: What is the highest sulphur application rate for grass
(lawn) (bluegrass and fescue) without damaging it?




I have a well. From which the well pump draws water. In this water is
much diluted hydrogen sulfide gas. To reduce this gas significantly, I
use a aerator bottle. The bottle then carries a significant amount of
diluted sulphuric acid. Every 24 hours by a timer, the bottle is flushed
with the same water. Total flush amount is 35 gallons. The ingredients
go to a french drain consisting of limestone rock of all different sizes.
The drain area is 10' wide X 10' long X 8' deep. The french drain is
uphill from several live oaks in the yard proper. During heavy rain
periods, above the french drain, the St. Augustine is very spongy when
walking on it. Has been this way for 2 years now.

Its obvious to me the live oaks immediately downhill from this french
drain are getting various amounts of, and various concentrations of H2SO4
(sulfuric acid). Yet, appear no different than other live oaks growing
wild in the surrounding area. The closest live oak has its trunk within
15 ft of the french drain boundary on the downhill side from the french
drain.

Native surface soil is nil to insignificant. Surface soil is generally a
gray clay that is always very quick to dry. Subsurface is fractured
limestone and caliche.

Is this addition of diluted sulphuric acid detrimental or aiding to the
soil and subsurface soil, or the live oaks themselves?
Dave

Its obvious to me the live oaks immediately downhill from this french
drain are getting various amounts of, and various concentrations of H2SO4
(sulfuric acid).

One thought is you could monitor the vitality of the trees with a
Shigometer. One function of the meter is to measure the Cambium Electrical
Resistance (CER). You could monitor the vitality of your live oaks with the
meter. I have one and need to use it more in consulting. It is more
accurate than just a casual observation. I could go into more detail and
better explain the process if you like. I have records on the CER of live
oaks at Tulane University in Louisiana. The test were taken from 11-16-1998
and 11-20-1998. The mean of 40 trees tested at breast height was 6.3. Out
of the 40 trees the low number was 4.1 and the high number was 10.7.

At the base of the trees the flare, which is trunk tissue, was tested and
suggested in some cases that there was woody root symplast decline. The
mean trunk flare out of 11 trees tested was 5.7. I.e., Trunk flare CER mean
of 5.7. The trunk flare high was 19.8 and the low was 3.1. When there is
more electrical resistance of the trunk flare, compared to the reading at
breast height, than I believe there is a suggestion that the woody root
associated with that trunk flare, is in a state of decline. I read data
suggestioning such observations and I cannot find the doc. I know I read it
and filed the paper in my files but I just can't find it. The work and
paper may have been by Dr. Shortle with the USFS. He did many studies with
the Shigometer. Again, if anybody on the list is in PA, NJ or MD, I could
demonstrate the meter.


--
Sincerely,
John A. Keslick, Jr.
Consulting 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.

On Oct 19, 7:21 am, "symplastless" wrote:
One of the problems with lowering the pH with sulfur is that the soil will
revert back.
Something that may interest you. I did a few soil studies on my own in old
growth forest. We tested for many essential elements and pH. In a old
growth forest which contained white pine and hemlock we got a pH average of
4.2 in the upper four inches of soil. This sample was taken from
Pennsylvania with the approval of the US Forest Service. I took the samples
in the area of soil where the mycorrhizae and rhizoplane was. Not inside
the rhizoplane. I understand that it is very difficult to get samples
actually from the rhizoplane. That is really where the samples should come
from because you will get different results there. As far as turf goes, it
likes high pH. Properly applying mulch could greatly help your situation.
Correct Mulching "suggestion". See "proper mulching".http://home.ccil.org/~treeman/sub3.html

Two well written articles on soil chemistry and such are hehttp://home.ccil.org/~treeman/shigo/RHIZO.html

http://home.ccil.org/~treeman/shigo/CHEM.html

[The soil report recommendation is to add 32 pounds of

sulphur (sulfur) to a depth of 12 inches per 1000 square feet (or 8
pounds to a 3 inch depth).]

The rhizoplane and rhizosphere where the absorption takes place, is usually
in the upper four inches of soil. There is no way I would put the sulfur
12" deep. I would think it would move downward rather then upward.
Actually I would

Several internet sources recommend putting

the sulphur in approx. 12 inch deep holes in a 2 foot by 2 foot grid
around the tree. They also suggest a 1 to 1 ratio of sulphur and iron
sulfate (ferrous sulphate/copperas) to add iron in addition to
lowering the pH.
Question 1: Will the localized high sulphur concentrations do harm to
the trees?
Question 2: What is the highest sulphur application rate for grass
(lawn) (bluegrass and fescue) without damaging it?

Thank you for your excellent comments and references. They are
fascinating. It appears, however, your last thought got cut off. You
said:
"The rhizoplane and rhizosphere where the absorption takes place, is
usually
in the upper four inches of soil. There is no way I would put the
sulfur
12" deep. I would think it would move downward rather then upward.
Actually I would" (WOULD WHAT???)

Please finish your thought. Thanks again!

On Oct 18, 10:23 pm, "David E. Ross" wrote:
On 10/18/2007 3:17 PM, wrote:

I have been using Medicap Fe trunk implants very successfully to fight
iron chlorosis in my many pin oak trees for 15 years. Soil samples
show my pH to be 7.3 minimum and 7.6 near our long concrete cement
driveway. The soil report recommendation is to add 32 pounds of
sulphur (sulfur) to a depth of 12 inches per 1000 square feet (or 8
pounds to a 3 inch depth). Several internet sources recommend putting
the sulphur in approx. 12 inch deep holes in a 2 foot by 2 foot grid
around the tree. They also suggest a 1 to 1 ratio of sulphur and iron
sulfate (ferrous sulphate/copperas) to add iron in addition to
lowering the pH.
Question 1: Will the localized high sulphur concentrations do harm to
the trees?
Question 2: What is the highest sulphur application rate for grass
(lawn) (bluegrass and fescue) without damaging it?

To acidify your soil, the sulfur must be converted into sulfuric acid by
soil bacteria. This happens slowly. For best results, make several
light applications repeatedly instead of applying the entire amount all
at once. This will help prevent killing the beneficial soil fungi since
sulfur is a natural fungicide. It helps if there is a good leaf mulch
that has started to decompose into leaf mold. (Oaks really need this in
their root zone.) Then the sulfuric acid will be formed on the soil
surface, and you won't have to dig. (Digging in the root zone of an oak
can kill the tree.)

You should also add some gypsum (calcium sulfate). A significant amount
can be added without the damage that might be caused by a significant
amount of elemental sulfur.

In the end, you will find that it takes more work and time to acidify an
alkaline soil than it takes to neutralize an acidic soil.

By the way, in my area, native oaks thrive in the native soil, which
tends to be alkaline. However, pin oaks (Quercus palustris) are native
to the eastern U.S. where many soils are indeed acidic, not California.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/

Thanks for your insights. One question, however. You said:
"For best results, make several light applications repeatedly instead
of applying the entire amount all
at once."
Can you put a number on a "light" or "heavy" application? How would
you rank 8 lb. sulphur per 1000 sq.ft.?

There is no way I would put the
sulfur
12" deep. I would think it would move downward rather then upward.
Actually I would" (WOULD WHAT???)

Please finish your thought. Thanks again!


I am not sure. I would place it on top and then apply mulch over it? Just
a thought. Also a biodynamic farmer once explained to me that any chemicals
going to the tree, can be mixed in the chip pile as it is composting. He
placed everything he was adding to the chip pile and then to the tree. Just
a thought.

--
Sincerely,
John A. Keslick, Jr.
Consulting 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.

On 10/20/2007 12:48 PM, Don wrote:
On Oct 18, 10:23 pm, "David E. Ross" wrote:
On 10/18/2007 3:17 PM, wrote:

I have been using Medicap Fe trunk implants very successfully to fight
iron chlorosis in my many pin oak trees for 15 years. Soil samples
show my pH to be 7.3 minimum and 7.6 near our long concrete cement
driveway. The soil report recommendation is to add 32 pounds of
sulphur (sulfur) to a depth of 12 inches per 1000 square feet (or 8
pounds to a 3 inch depth). Several internet sources recommend putting
the sulphur in approx. 12 inch deep holes in a 2 foot by 2 foot grid
around the tree. They also suggest a 1 to 1 ratio of sulphur and iron
sulfate (ferrous sulphate/copperas) to add iron in addition to
lowering the pH.
Question 1: Will the localized high sulphur concentrations do harm to
the trees?
Question 2: What is the highest sulphur application rate for grass
(lawn) (bluegrass and fescue) without damaging it?
To acidify your soil, the sulfur must be converted into sulfuric acid by
soil bacteria. This happens slowly. For best results, make several
light applications repeatedly instead of applying the entire amount all
at once. This will help prevent killing the beneficial soil fungi since
sulfur is a natural fungicide. It helps if there is a good leaf mulch
that has started to decompose into leaf mold. (Oaks really need this in
their root zone.) Then the sulfuric acid will be formed on the soil
surface, and you won't have to dig. (Digging in the root zone of an oak
can kill the tree.)

You should also add some gypsum (calcium sulfate). A significant amount
can be added without the damage that might be caused by a significant
amount of elemental sulfur.

In the end, you will find that it takes more work and time to acidify an
alkaline soil than it takes to neutralize an acidic soil.

By the way, in my area, native oaks thrive in the native soil, which
tends to be alkaline. However, pin oaks (Quercus palustris) are native
to the eastern U.S. where many soils are indeed acidic, not California.


Thanks for your insights. One question, however. You said:
"For best results, make several light applications repeatedly instead
of applying the entire amount all
at once."
Can you put a number on a "light" or "heavy" application? How would
you rank 8 lb. sulphur per 1000 sq.ft.?


I would apply a third at annual intervals in the early spring. Yes,
that means it takes three year to do it all.

In an alkaline soil, the acid might be neutralized almost as quickly as
it is formed. Thus, you want a continuous seeping of acid over time, to
finally overcome the alkalinity.

In any case, the conversion of sulfur into sulfuric acid is slow. You
won't speed it up by applying extra sulfur, but you might have an
adverse impact on beneficial soil organisms if you apply too much at one
time.

Note that, if you have a good mulch of compost or composting leaves, you
don't have to dig the sulfur into the soil. Just rinse it through the
mulch, which already contains acidifying bacteria. Sulfur won't
dissolve and leach into the soil, but sulfuric acid will indeed leach
into the soil.

Once you get the results you want, you should probably broadcast a
smaller amount of sulfur and gypsum together, each spring. If your soil
is naturally alkaline (as mine is), the acid will eventually be
neutralized no matter what you do. So you must keep renewing the acid.

I mix a double handful of sulfur and a double handful of gypsum and
broadcast that around my liquidambar tree each spring to prevent
cholorsis. (A landscaper suggested adding about 1/4 cup of Epsom salts,
which is magnesium sulfate.) With the first feeding of my roses, I
include about a handful of sulfur for each rose bush; I also include
about a tablespoon of Epsom salts because the magnesium promotes the
growth of new canes. I don't usually add sulfur elsewhere in my garden
because I use a lot of ammonium sulfate as a fertilizer. My camellias
and azaleas get an acidic commercial fertilizer specific for them. My
citrus and gardenia get either the ammonium sulfate or commercial citrus
food, which is acidic; they also get added zinc sulfate. Finally, I use
a very large amount of gypsum (calcium sulfate), about 1 lb a year per
100 square feet; this I generally broadcast in the late fall, just
before the winter rainy season.

You will notice that, although I don't use sulfur all over my garden, I
do use sulfur-containing fertilizers. However, I avoid using these on
iris, primroses, and dianthus, all of which prefer an alkaline soil. It
gets tricky since I have dianthus right next to azaleas.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/

BTW I am not a big fan of injections and implants. Implants can kill alot
of the parenchyma cells if I recall correctly. As a person that offers
organic tree care as a profession, I tend to try to protect the symplast.

--
Sincerely,
John A. Keslick, Jr.
Consulting 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.

"David E. Ross" wrote in message
...
On 10/20/2007 12:48 PM, Don wrote:
On Oct 18, 10:23 pm, "David E. Ross" wrote:
On 10/18/2007 3:17 PM, wrote:

I have been using Medicap Fe trunk implants very successfully to fight
iron chlorosis in my many pin oak trees for 15 years. Soil samples
show my pH to be 7.3 minimum and 7.6 near our long concrete cement
driveway. The soil report recommendation is to add 32 pounds of
sulphur (sulfur) to a depth of 12 inches per 1000 square feet (or 8
pounds to a 3 inch depth). Several internet sources recommend putting
the sulphur in approx. 12 inch deep holes in a 2 foot by 2 foot grid
around the tree. They also suggest a 1 to 1 ratio of sulphur and iron
sulfate (ferrous sulphate/copperas) to add iron in addition to
lowering the pH.
Question 1: Will the localized high sulphur concentrations do harm to
the trees?
Question 2: What is the highest sulphur application rate for grass
(lawn) (bluegrass and fescue) without damaging it?
To acidify your soil, the sulfur must be converted into sulfuric acid by
soil bacteria. This happens slowly. For best results, make several
light applications repeatedly instead of applying the entire amount all
at once. This will help prevent killing the beneficial soil fungi since
sulfur is a natural fungicide. It helps if there is a good leaf mulch
that has started to decompose into leaf mold. (Oaks really need this in
their root zone.) Then the sulfuric acid will be formed on the soil
surface, and you won't have to dig. (Digging in the root zone of an oak
can kill the tree.)

You should also add some gypsum (calcium sulfate). A significant amount
can be added without the damage that might be caused by a significant
amount of elemental sulfur.

In the end, you will find that it takes more work and time to acidify an
alkaline soil than it takes to neutralize an acidic soil.

By the way, in my area, native oaks thrive in the native soil, which
tends to be alkaline. However, pin oaks (Quercus palustris) are native
to the eastern U.S. where many soils are indeed acidic, not California.


Thanks for your insights. One question, however. You said:
"For best results, make several light applications repeatedly instead
of applying the entire amount all
at once."
Can you put a number on a "light" or "heavy" application? How would
you rank 8 lb. sulphur per 1000 sq.ft.?


I would apply a third at annual intervals in the early spring. Yes,
that means it takes three year to do it all.

In an alkaline soil, the acid might be neutralized almost as quickly as
it is formed. Thus, you want a continuous seeping of acid over time, to
finally overcome the alkalinity.

In any case, the conversion of sulfur into sulfuric acid is slow. You
won't speed it up by applying extra sulfur, but you might have an
adverse impact on beneficial soil organisms if you apply too much at one
time.

Note that, if you have a good mulch of compost or composting leaves, you
don't have to dig the sulfur into the soil. Just rinse it through the
mulch, which already contains acidifying bacteria. Sulfur won't
dissolve and leach into the soil, but sulfuric acid will indeed leach
into the soil.

Once you get the results you want, you should probably broadcast a
smaller amount of sulfur and gypsum together, each spring. If your soil
is naturally alkaline (as mine is), the acid will eventually be
neutralized no matter what you do. So you must keep renewing the acid.

I mix a double handful of sulfur and a double handful of gypsum and
broadcast that around my liquidambar tree each spring to prevent
cholorsis. (A landscaper suggested adding about 1/4 cup of Epsom salts,
which is magnesium sulfate.) With the first feeding of my roses, I
include about a handful of sulfur for each rose bush; I also include
about a tablespoon of Epsom salts because the magnesium promotes the
growth of new canes. I don't usually add sulfur elsewhere in my garden
because I use a lot of ammonium sulfate as a fertilizer. My camellias
and azaleas get an acidic commercial fertilizer specific for them. My
citrus and gardenia get either the ammonium sulfate or commercial citrus
food, which is acidic; they also get added zinc sulfate. Finally, I use
a very large amount of gypsum (calcium sulfate), about 1 lb a year per
100 square feet; this I generally broadcast in the late fall, just
before the winter rainy season.

You will notice that, although I don't use sulfur all over my garden, I
do use sulfur-containing fertilizers. However, I avoid using these on
iris, primroses, and dianthus, all of which prefer an alkaline soil. It
gets tricky since I have dianthus right next to azaleas.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/