In article ,
"Stephen M. Henning" wrote:

(paghat) wrote:

"Correcting" soil with peat, sphagnum, or acidifying fertilizers does more
harm than good even in the short run.

Actually the correct way to raise a broad spectrum of acid loving
rhododendron and azalea plants in an alkaline area is to use a raised
bed. You build up a raised bed with landscape timbers (nontoxic treated
wood or wood substitute). Then you get acidic or neutral soil and mix
it with good organic material. Since rhododendrons and azaleas have
shallow roots, if the raised bed is at least 10 to 12 inches high with a
gravel layer on the bottom, the alkaline soil will have no effect on the
rhododendrons and azaleas.

Unfortunately if you lived in a part of the united states where the larger
environment is alkaline, so eventually will become that little hump. And
asthe Edinburg study showed, it really doesn't work to change the pH
reading of limy soils. They have to be grown in soils that never were
limy, OR one has to select lime-tolerant varieties and not alter the pH
reading at all.

I was at the Rhododendron Species Foundation in Federal Way, WA, last
week. They had a large, over 20' tall, rhododendron they were
transplanting. The roots ball was less than 8 inches thick. They had
the roots sandwiched between two shipping pallets. That is the first
time I saw how really shallow rhododendron roots are on a very large
plant.

I'm in the midst of moving five large old shrubs from a friend's house to
mine. Not 20 feet, but six to nine footers, very old. He didn't believe
we'd ever get them up, but I spaded a drip-line circle which missed all
the roots, then levered it upword with only the lightest tearing sound, &
voila, it was ready to move.

It definitely is surprising how little a root system they require to
sustain such a large shrub.

The alkaline areas that I plant in are near the foundation of my home.
The mortar in the stone walls leaches out and tends to sweeten the soil.
I compensate for this as needed by using sulfur powder when I see
chlorotic leaves. It lasts for many years between treatments. On new
homes, the effect be more transient. The soil is OK, but the salts that
are passing through it are the problem. Sulphur is able to handle that
problem.

You're speaking from the point of view of someone who luckily lives in a
region with naturally acidic soils. Even soils next to concrete walls, if
watered regularly, return to an acidic state, no artificial help required.
Concrete does NOT leech much alkalinity unless the concrete is losing
cohesion & turning to powder. It alkalinizes soil temporarily from watery
run-off when still curing (which for my hosue would've been nine decades
ago), but only if never watered AND sheltered under eaves so it never gets
rained on would it remain alkaline indefinitely. If your concrete
foundation is honestly re-alkalinizing your soil so that you have to
repeatedly add sulphur, your house is going to fall down into the powdery
residue of the dissolved concrete.

I works both ways: In a larger environment of naturally acidic soils,
alkalinized pockets will slowly re-acidify. You & I live in naturally
acidic soil environments, & any tinkering with pH readings we may do for
rhodies would be shooting toward what is normal, & we're not bucking
against nature. Someone who lived amidst naturally limy soils will really
have to select the lime-tolerant species-rhodies or grafted rhodies. As
the Edinburg study showed, attempting to acidify soils which are naturaly
limy locks in manganese so the shrubs become chloratic -- faster & worse
than if the pH reading had never been "corrected." I couldn't remember the
trial leader's name yesterday, but I looked him up, it was Professor David
Rankin, whose work in the last two years has corrected a lot of mistaken
thinking about growing rhodies in naturally alkaline environments. Part of
the reason it previously seemed so difficult was BECAUSE of the doomed
attempt to change pH readings before planting, resulting in
locked-manganese & doomed shrubs.

-paghat the ratgirl

--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
See the Garden of Paghat the Ratgirl: http://www.paghat.com/