"David E. Ross" wrote in message
. ..
On 9/10/2007 8:33 AM, MVD wrote:
I live in Northern Illinois where (unfortunately) the native soils
contain a good deal of heavy clays. This spring I was given a dry root
hibiscus, which I planted, admitted without enough thought of
conditioning the soil in which I was planting it. The hibiscus has,
in my opinion, grown nicely this summer, although it has not
flowered. The three to four foot radius around the hibiscus is free
of other plants or shrubs. The soil in this area seems to be quite
compacted and is showing some large cracks. I was wondering whether
it would be wise to careful dig up the soil in this area and mix in
some peat moss with the soil that is there. Is this is a good idea?
Would be benefit the hibiscus? Can it be done without disturbing and
damaging the hibiscus? Any one have an idea for the best method for
doing such a thing?


Broadcast about a 1/4-inch layer of gypsum over the area. Sprinkle with
just enough water to wet the gypsum but not rinse it away. Wait a day.
Water slightly more generously to start the gypsum dissolving. Wait a
day. Soak the area with a slow hose; that is, let the hose slowly
trickle to start rinsing the gypsum into the soil.

The gypsum will react chemically with the clay, causing it to lose its
stickiness and become somewhat granular. This treatment should be
renewed every spring, before the summer rains. (Contrary to common
belief, there is generally more moisture in the summer rains than in the
winter snows in your area.)

--
David E. Ross


A friend of mine had great results with gypsum, although she added a step.
She used a pitch fork to poke holes straight down and made sure some of the
gypsum was sprinkled into those holes. After two seasons, the soil's quite a
bit easier to work with.