lowering soil pH

I was going to say "sulfur" but then didn't know how much...and guess
what I found in my local Central Indiana paper: an article on raising
soil pH for rhodos.  Since I couldn't find it online, I'm just re-typing
the text from our Purdue U. Extension Educator, Doug Akers...(he's
good!)  Here's what he says...

"...For small area, now would be a good time to have a soil test done to
see if you pH is too high. If so, sulfur can be added either now or in
the spring to lower the pH. Different textures of soil require different
amounts of sulfur to lower the pH.  A sandy soil needs seven pounds of
sulfur per 1.000 square feet to lower the pH one point. A loam soil needs
11 pounds and clay needs 17 pounds to do the same. For example, if you
wish to lower the pH from 8.5 to 6.5 on a loam soil, you would need 22
pounds of sulfur per 1,000 square feet.

Sulfur and aluminum sulfate can be added to the soil to lower the pH
(more acid). Aluminum sulfate will change the soil pH instantly because
the aluminum produces the acidity as soon as it dissolves in the soil. 
Sulfur, however, requires some time for the conversion to sulfuric acid
with the aid of soil bacteria.
In the absence of a soil test, add 1-2 cups of elemental sulfur  (90%
sulfur) per 10 square feet prior to planting and mix it into the soil to
a depth of 12 inches.  Or, if the plant is already in the ground,
broadcast (apply on the surface) a cup of sulfur per 10  square feel and
water-in.  Up to 10 pounds sulfur per 100 square feet can be applied to
the soil surface without damaging  turf.

Sulfur may take 3 to 6 months to react. Aluminum sulfate reacts quicker,
but sulfur last longer and has nearly seven times the acidifying power,
according to A&L Great Lakes Laboratories in Ft. Wayne (Indiana). "

I hope this is helpful,
Lynn
Zn 5 Central Indiana

Lynn Jenkins
Indiana Living Green
a hoosier's guide to a sustainable lifestyle
www.IndianaLivingGreen.com
Lynn@IndianaLivingGreen.com

At 03:48 PM 11/8/2006, you wrote:

  One solution with Rhododendrons is to plant them on a raised bed as
  to minimize the need to acidify the soil. Avoid Aluminum Sulfate as
  the Aluminum can build up to toxic levels.

  Bill Plummer

  ----- Original Message ----- From: "Don Martinson" <LLmen@wi.rr.com>
  To: <woodyplants@hort.net>
  Sent: Wednesday, November 08, 2006 2:49 PM
  Subject: Redvein enkianthus

    For years, I lusted over the redvein enkianthus (Enkianthus
    campanulatus),
    but could never get the small mail-order plants
    I purchased to survive.  I realize one of the problems was that I
    was not as
    diligent at acidifying
    the soil (soil pH here in SE Wisconsin is about 8) as I should
    have been.

    Last week, at one of the local garden center9s end of the season
    sell-off
    (75% off!), I found a nice 3 ft tall
    multi-branched specimen.  While I9m familiar with many of the
    soil
    acidifiers, peat, sulphur, aluminum sulfate,
    etc., I9m not sure how often these need to be supplied and in
    what
    quantities.

    Do any of you have any practical experience with this shrub where
    you need
    to periodically acidify the soil?

    Thanks,

    Don Martinson
    Milwaukee, Wisconsin
    l*@wi.rr.com

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