Just came back from a week's holiday to find one of the overflow pipes
(central heating or hot water tank, I don't know which) dripping into
a potted rhododendron.

I suspect the water's got a lot of lime in it because there's white
stains all over an adjacent window, and the rhododendron's looking
very sick now -- all dried out, with all the leaves either curling
outwards or yellow.

I've put some coffee grounds around it and watered it with a solution
containing a couple of teaspoons of vinegar, to try to get the acidity
back up. Any other ideas? The plant must be at least 10 years old (I
acquired it from a relative) and is about 5 feet tall.

--
_____ . . |
Carl Warnell ' o/ FORE! . . |
| . . . . |
/| . . ...o

On Fri, 01 Aug 2003 13:56:30 +0100, Carl Warnell
wrote:

Just came back from a week's holiday to find one of the overflow pipes
(central heating or hot water tank, I don't know which) dripping into
a potted rhododendron.

I suspect the water's got a lot of lime in it because there's white
stains all over an adjacent window, and the rhododendron's looking
very sick now -- all dried out, with all the leaves either curling
outwards or yellow.

I've put some coffee grounds around it and watered it with a solution
containing a couple of teaspoons of vinegar, to try to get the acidity
back up. Any other ideas? The plant must be at least 10 years old (I
acquired it from a relative) and is about 5 feet tall.

Much depends on where the water came from. I don't think the coffee
grounds or the vinegar will help much.

If it's central heating water, there's every possibility that there's
a corrosion inhibitor in the water which may well be poisonous to
plants. If it were mine I'd make serious efforts to flush the root
system to clear it out. Unpot it, wash off as much of the old soil as
possible and re-pot into fresh ericaceous compost, working it well
into the root structure, and say a prayer. But it sounds terminal to
me.

If it were just alkaline tap water the effect wouldn't have happened
so quickly. Nor would it be looking 'all dried out' as you say, as the
root ball would be moist. Unless of course it's drowned, but I'd have
thought that unlikely.


--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net

On Sat, 02 Aug 2003 18:24:12 +0100, Chris Hogg wrote:

On Fri, 01 Aug 2003 13:56:30 +0100, Carl Warnell
wrote:


I've put some coffee grounds around it and watered it with a solution
containing a couple of teaspoons of vinegar, to try to get the acidity
back up. Any other ideas? The plant must be at least 10 years old (I
acquired it from a relative) and is about 5 feet tall.

Much depends on where the water came from. I don't think the coffee
grounds or the vinegar will help much.

On the same theme just how would you "Acidify" soil to make
Rhododendrons etc more comfortable.

TIA

Paul

On Mon, 04 Aug 2003 12:38:58 +0100, Retired_Paul
wrote:

On Sat, 02 Aug 2003 18:24:12 +0100, Chris Hogg wrote:

On Fri, 01 Aug 2003 13:56:30 +0100, Carl Warnell
wrote:


I've put some coffee grounds around it and watered it with a solution
containing a couple of teaspoons of vinegar, to try to get the acidity
back up. Any other ideas? The plant must be at least 10 years old (I
acquired it from a relative) and is about 5 feet tall.

Much depends on where the water came from. I don't think the coffee
grounds or the vinegar will help much.

On the same theme just how would you "Acidify" soil to make
Rhododendrons etc more comfortable.

TIA

Paul
'Acidifying' soil as such is quite difficult. If it's chalky, you've
no hope, because the chalk holds the pH high, and the only way to
acidify it is to dissolve all the chalk. If the soil is only very
slightly alkaline or neutral, then adding acid compost regularly over
a period of years may increase the acidity slightly. But your best bet
is to water on sequestered iron and trace elements. These don't change
the acidity (contrary to what the labels imply) but they do provide
the nutrients not available in alkaline soils. Look for 'ericaceous'
fertilisers, or those containing sequestered iron and trace elements.


--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net

On Mon, 04 Aug 2003 18:25:33 +0100, Chris Hogg wrote:



On the same theme just how would you "Acidify" soil to make
Rhododendrons etc more comfortable.

TIA

Paul
'Acidifying' soil as such is quite difficult. If it's chalky, you've
no hope, because the chalk holds the pH high, and the only way to
acidify it is to dissolve all the chalk. If the soil is only very
slightly alkaline or neutral, then adding acid compost regularly over
a period of years may increase the acidity slightly. But your best bet
is to water on sequestered iron and trace elements. These don't change
the acidity (contrary to what the labels imply) but they do provide
the nutrients not available in alkaline soils. Look for 'ericaceous'
fertilisers, or those containing sequestered iron and trace elements.

I will look around for some sequestered iron stuff then, the soil is
clay but the Rhododendrons don't look too happy.

Thanks

Paul

"Retired_Paul" wrote in message
...
On Mon, 04 Aug 2003 18:25:33 +0100, Chris Hogg wrote:



On the same theme just how would you "Acidify" soil to make
Rhododendrons etc more comfortable.

TIA

Paul
'Acidifying' soil as such is quite difficult. If it's chalky, you've
no hope, because the chalk holds the pH high, and the only way to
acidify it is to dissolve all the chalk. If the soil is only very
slightly alkaline or neutral, then adding acid compost regularly over
a period of years may increase the acidity slightly. But your best bet
is to water on sequestered iron and trace elements. These don't change
the acidity (contrary to what the labels imply) but they do provide
the nutrients not available in alkaline soils. Look for 'ericaceous'
fertilisers, or those containing sequestered iron and trace elements.

I will look around for some sequestered iron stuff then, the soil is
clay but the Rhododendrons don't look too happy.


Have you considered it might be some sort of fungal infection? Rhododendrons
are known to be carriers of the fungus which causes Sudden Oak Death, for
example.

On Mon, 04 Aug 2003 19:06:19 +0100, Retired_Paul
wrote:

On Mon, 04 Aug 2003 18:25:33 +0100, Chris Hogg wrote:



On the same theme just how would you "Acidify" soil to make
Rhododendrons etc more comfortable.

TIA

Paul
'Acidifying' soil as such is quite difficult. If it's chalky, you've
no hope, because the chalk holds the pH high, and the only way to
acidify it is to dissolve all the chalk. If the soil is only very
slightly alkaline or neutral, then adding acid compost regularly over
a period of years may increase the acidity slightly. But your best bet
is to water on sequestered iron and trace elements. These don't change
the acidity (contrary to what the labels imply) but they do provide
the nutrients not available in alkaline soils. Look for 'ericaceous'
fertilisers, or those containing sequestered iron and trace elements.

I will look around for some sequestered iron stuff then, the soil is
clay but the Rhododendrons don't look too happy.

Thanks

Paul
Many clay soils are on the acid side. Have you actually checked the pH
with a testing kit (obtainable from garden centres etc)?
Alternatively, it might be poor drainage, or just lack of feed.


--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net

"Chris Hogg" wrote in message
...
On Mon, 04 Aug 2003 12:38:58 +0100, Retired_Paul
wrote:

On Sat, 02 Aug 2003 18:24:12 +0100, Chris Hogg wrote:

On Fri, 01 Aug 2003 13:56:30 +0100, Carl Warnell
wrote:


I've put some coffee grounds around it and watered it with a solution
containing a couple of teaspoons of vinegar, to try to get the acidity
back up. Any other ideas? The plant must be at least 10 years old (I
acquired it from a relative) and is about 5 feet tall.

Much depends on where the water came from. I don't think the coffee
grounds or the vinegar will help much.

On the same theme just how would you "Acidify" soil to make
Rhododendrons etc more comfortable.

TIA

Paul
'Acidifying' soil as such is quite difficult. If it's chalky, you've
no hope, because the chalk holds the pH high, and the only way to
acidify it is to dissolve all the chalk. If the soil is only very
slightly alkaline or neutral, then adding acid compost regularly over
a period of years may increase the acidity slightly. But your best bet
is to water on sequestered iron and trace elements.

Using "Miracid" gives you the best of both worlds. It sontains both
phosphorus pentoxide and sequestered iron. The former slowly forms
phosphoric acid when reacting with the soil moisture. I do grant you that
if the soil actually is largely chalk or limestone, you will not be able to
acidify it without dissolving away all the soil.

These don't change
the acidity (contrary to what the labels imply) but they do provide
the nutrients not available in alkaline soils. Look for 'ericaceous'
fertilisers, or those containing sequestered iron and trace elements.

[Franz Heymann]

On Tue, 5 Aug 2003 19:57:09 +0000 (UTC), Franz Heymann wrote:

Using "Miracid" gives you the best of both worlds. It sontains both
phosphorus pentoxide and sequestered iron.

You don't know what you are writing about. The phosphorus content
of fertilizers is measured *as*if* it were in the form of
phosphorus pentoxide, but I assure you that Miracid does NOT
contain phosphorus in that chemical combination.

And the word "sequestered" is also improper: the correct term is
"chelated", even if the commercial name is "sequestrene".


--
Rodger Whitlock
Victoria, British Columbia, Canada

"Rodger Whitlock" wrote in
message ...
On Tue, 5 Aug 2003 19:57:09 +0000 (UTC), Franz Heymann wrote:

Using "Miracid" gives you the best of both worlds. It sontains both
phosphorus pentoxide and sequestered iron.

You don't know what you are writing about.

That is highly likely. I frequently do. It sounds as if readers should
disregard my previous contribution.

I would now love to hear an explanation of why the package of Miracid says
quite clearly
"Soil Acidifier Plant Food".

[Franz Heymann]

On Wed, 6 Aug 2003 08:43:15 +0000 (UTC), Franz Heymann wrote:

I would now love to hear an explanation of why the package of Miracid says
quite clearly
"Soil Acidifier Plant Food".

Because (a) it's chemical makeup is such that it acidifies the
soil -- but just how much and under what conditions remains
unstated; and (b) it contains primary plant foods.

Someone else replied by email pointing out that the box says
"contains phosphorous pentoxide in a neutral ammonium citrate
solution". That may be a statement of how they make the stuff,
but it's not a statement of what's in the box because of the
interactions of the ingredients, esp. phosophorus pentoxide in
solution. Nick McLaren's chemistry may be less rusty than mine
and able to elucidate this.

While perhaps it's true that legally speaking, "contains" means
"we made it out of X", FH's misapprehension that "contains
phosphorus pentoxide" meant just what it said led to a
misunderstanding of the actual chemistry.

My email correspondent also mentioned that the box uses the word
"sequestered", but also "chelated".


--
Rodger Whitlock
Victoria, British Columbia, Canada

"Rodger Whitlock" wrote in
message ...
On Wed, 6 Aug 2003 08:43:15 +0000 (UTC), Franz Heymann wrote:

I would now love to hear an explanation of why the package of Miracid
says
quite clearly
"Soil Acidifier Plant Food".

Because (a) it's chemical makeup is such that it acidifies the
soil -- but just how much and under what conditions remains
unstated;

If it really is capable of acidifying the soil, I would have thought that it
must contain an acid. I am still ignorant of what the acid might be.
I have just done a quick test with a piece of litmus paper in a solution of
Miracid roughly 5 times the recommended strength, and the paper colour is
hardly any different from that of neutral water. I am beginning to have my
doubts about the claim that it is a soil acidifier.

and (b) it contains primary plant foods.

There is no doubt about that.

Someone else replied by email pointing out that the box says
"contains phosphorous pentoxide in a neutral ammonium citrate
solution".

I wish folk would respond to items in this newsletter by contributing to the
newsletter. In any case, the reply is inaccurate. My Miracid is not a
solution at all. It consists of granules. The box axtually says (and I
quote)
"Phosphorus Pentoxide P2O5 soluble in neutral ammonium citrate and in water
10% (4.4%P)"
My guess is that the box is simply trying to say that there are 10% soluble
phosphates in the product, with the phosphate content measured in terms of
the relative amount of phosphate ion in the product.

If I may hark back to my earlier faux pas about stating that the P2O5
referred to an actual phosphorus pentoxide ingredient: I should have
realised that I was talking nonsense in a fit of depravity, because I have
handled P2O5 for decades as a drying agent in vacuum systems. It is an
intense hygroscopic and frighteningly corrosive substance, quite unsuitable
for use "as is" in a gardening chemical. I can blame only my steadily
advancing senility for my mistake.

That may be a statement of how they make the stuff,
but it's not a statement of what's in the box because of the
interactions of the ingredients, esp. phosophorus pentoxide in
solution. Nick McLaren's chemistry may be less rusty than mine
and able to elucidate this.

While perhaps it's true that legally speaking, "contains" means
"we made it out of X", FH's misapprehension that "contains
phosphorus pentoxide" meant just what it said led to a
misunderstanding of the actual chemistry.

Yes, indeed.

My email correspondent also mentioned that the box uses the word
"sequestered", but also "chelated".

[Franz Heymann]