I have a plant that has been getting lighter green as it gets bigger. I
thought the problem was nitrogen so I added some Miracle-Gro to the water.
It didn't seem to have any effect.

Today I tested the pH of my soil, and it's 9. Recommended value is 5-7.
How can I safely acidify a potted plant?

(Pointers to a FAQ page welcome ... if this is a FAQ.)

-- spud_demon -at- thundermaker.net
The above may not (yet) represent the opinions of my employer.

On 2005-11-30 12:10:34 -0500, (Spud Demon) said:

I have a plant that has been getting lighter green as it gets bigger. I
thought the problem was nitrogen so I added some Miracle-Gro to the water.
It didn't seem to have any effect.

Today I tested the pH of my soil, and it's 9. Recommended value is
5-7. How can I safely acidify a potted plant?

(Pointers to a FAQ page welcome ... if this is a FAQ.)


http://www.savvygardener.com/Features/soil_ph.html


Google is your friend!

--
Chris: "Dad, what's a blowhole for?"
Peter: "I'll tell you what it's NOT for and then you'll know why I can
never go back to Sea World."

(Spud Demon) wrote:

I have a plant that has been getting lighter green as it gets bigger. I
thought the problem was nitrogen so I added some Miracle-Gro to the water.
It didn't seem to have any effect.

Today I tested the pH of my soil, and it's 9. Recommended value is 5-7.
How can I safely acidify a potted plant?

It sounds like you have an azalea. Anyway, what ever it is, you can use
powdered sulfur to lower the pH. Do not use aluminum sulfate. It is
good for hydrangeas but eventually kills plants like azaleas. They
can't tolerate high aluminum levels.

Also, there is a product MirAcid put out by MiracleGro. I am not a fan
of it, but it would be better than MiracleGro. However over-fertilizing
can be the problem*. First, try some sulfur. It is slow acting, so
wait a while. You might try some Epsom salts (magnesium sulfate). It
is good at greening up plants and will provide a little short term
acidification. Magnesium is an essential element and lack of it will
cause yellowish areas between the leaf veins on older leaves. If the
leaves are a solid green the addition of Epsom salts (magnesium sulfate)
would not be useful.

*Yellowing of a leaf between darl green veins is called chlorosis. Many
conditions can be responsible. 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.
A combination of acidification with sulfur and iron supplements such as
chelated iron or iron sulfate will usually treat this problem. 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.
--
Pardon my spam deterrent; send email to
Visit my Rhododendron and Azalea web pages at:
http://home.earthlink.net/~rhodyman/rhody.html
Also visit the Rhododendron and Azalea Bookstore at:
http://home.earthlink.net/~rhodyman/rhodybooks.html
Cheers, Steve Henning in Reading, PA USA Zone 6

The best remedy for a potted plant is to change the potting soil. What
could you have put in the pot to go pH 9. I don't know of any potting
soils that are more than neutral. I f you have an acid loving plant
requiring a pH below 6. there are specific potting mixtures for that
situation.

Thanks to all who replied, especially Stephen -- lots of useful info!

" writes in article . com dated 1 Dec 2005 07:48:56 -0800:
The best remedy for a potted plant is to change the potting soil. What
could you have put in the pot to go pH 9. I don't know of any potting
soils that are more than neutral. I f you have an acid loving plant
requiring a pH below 6. there are specific potting mixtures for that
situation.

The plant has been in the same soil for over a year but the problem is more
recent. All I added was water (through a new hose) and fertilizer. But
it's an undrained pot, maybe that has something to do with the pH going
crazy.

Anyway, last night I added half a cup of Epsom salt (Magnesium Sulfate)
mixed with a gallon of water. Later today I will re-check the pH.

I don't want to mess up the root ball by transplanting it in different soil,
but I might rinse it (overwater and then dump out the excess) if the
chemical/bacterial route doesn't work. That should bring the pH close to 7.

-- spud_demon -at- thundermaker.net
The above may not (yet) represent the opinions of my employer.

Spud Demon wrote:
Thanks to all who replied, especially Stephen -- lots of useful
info!

" writes in
article . com
dated 1 Dec 2005 07:48:56 -0800:
The best remedy for a potted plant is to change the potting
soil.
What could you have put in the pot to go pH 9. I don't know
of
any potting soils that are more than neutral. I f you have an
acid loving plant requiring a pH below 6. there are specific
potting mixtures for that situation.

The plant has been in the same soil for over a year but the
problem
is more
recent. All I added was water (through a new hose) and
fertilizer.
But
it's an undrained pot, maybe that has something to do with the
pH
going
crazy.

Anyway, last night I added half a cup of Epsom salt (Magnesium
Sulfate)
mixed with a gallon of water. Later today I will re-check the
pH.

I don't want to mess up the root ball by transplanting it in
different soil,
but I might rinse it (overwater and then dump out the excess)
if the
chemical/bacterial route doesn't work. That should bring the
pH
close to 7.

-- spud_demon -at- thundermaker.net
The above may not (yet) represent the opinions of my employer.

Plants should *never* be planted in a pot without drainage.

--

Travis in Shoreline (just North of Seattle) Washington
USDA Zone 8
Sunset Zone 5

On Thu, 1 Dec 2005 16:50:31 +0000 (UTC), Spud Demon wrote:

The plant has been in the same soil for over a year but the problem is more
recent. All I added was water (through a new hose) and fertilizer. But
it's an undrained pot, maybe that has something to do with the pH going
crazy.

Anyway, last night I added half a cup of Epsom salt (Magnesium Sulfate)
mixed with a gallon of water. Later today I will re-check the pH.

I don't want to mess up the root ball by transplanting it in different soil,
but I might rinse it (overwater and then dump out the excess) if the

In my opinion and experience, you'd be far better off getting that plant
out of the pot, soil rinsed from the roots, and then repotted into fresh
medium in a pot with proper drainage. Put the drained pot into the
undrained one, if you want to show it off -- and consider looking up
"double potting", where the space between the clay pot and the display
pot is packed with a fibrous, water-retentive medium like long strand
sphagnum.

Plants experience many more stresses in a pot than they do planted outside.
The root volume is restricted, the soil tends to collapse and become
oxygen deficient as organic matter is depleted, the plant tends to experience
drought-and-drown watering (especially a problem in an undrained container)
and salts tend to accumulate in teh soil, leading to tip burn of leaves
and eventually to the plant being unable to get adequate moisture from
the soil. Adding that half cup of mag sulfate (a salt) is going to accelerate
that salinization problem.

I don't know the specimen size you're dealing with here... I've repotted
lots of big plants myself, up to about 60 gallon containers, and
borrowed muscles for bigger containers. It's definitely work. But
the plant will do better in better growing conditions.

Kay

(Spud Demon) wrote:

The plant has been in the same soil for over a year but the problem is more
recent. All I added was water (through a new hose) and fertilizer. But
it's an undrained pot, maybe that has something to do with the pH going
crazy.

An undrained pot is going to kill the plant. First, salts in the water
build up to toxic levels. Second, the roots drown in the water in the
pot. Unless you have a bog plant, the plant is doomed. If it is a bog
plant, it will take a little longer to kill. Either drill a hole in the
bottom or move to a pot with a hole.

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

Quit screwing around, repot with fresh soil and provide pore space and
drainage.
Spud Demon wrote:
I have a plant that has been getting lighter green as it gets bigger. I
thought the problem was nitrogen so I added some Miracle-Gro to the water.
It didn't seem to have any effect.

Today I tested the pH of my soil, and it's 9. Recommended value is 5-7.
How can I safely acidify a potted plant?

(Pointers to a FAQ page welcome ... if this is a FAQ.)

-- spud_demon -at- thundermaker.net
The above may not (yet) represent the opinions of my employer.

My experience with high pH says to check the water you are watering with.
The soil tends to take on the pH of the water used. In my case my well water
tends to run with a pH 8 and pretty soon so is the soil in my house
plants. About once a month I use a acid type fertilizer (miracle grow for
acid plants). Seems to balance everything out over time. Put some holes in
the pot too. Using a fertilizer will build up salts real fast. Watering with
rain water is also helpful.

"Spud Demon" wrote in message
...
I have a plant that has been getting lighter green as it gets bigger. I
thought the problem was nitrogen so I added some Miracle-Gro to the water.
It didn't seem to have any effect.

Today I tested the pH of my soil, and it's 9. Recommended value is 5-7.
How can I safely acidify a potted plant?

(Pointers to a FAQ page welcome ... if this is a FAQ.)

-- spud_demon -at- thundermaker.net
The above may not (yet) represent the opinions of my employer.