On 8/8/12 2:02 PM, mdemetri2 wrote:
Hi, I have been 4 years in my current home, and the back garden pretty
much each year needs some new plants and shrubs. Although I admit we
have in the past bought what looks nice and arent necessarily suited for
our east facing heavy clay moisture retaining soil.

Firstly, I have over the last 2 months or so being contemplating
removing the soil/clay from our flower bed about a foot or so and
replacing with new soil mixed in with sand but adding more depth - so
allowing for a total of 15 inches of decent soil to replace the harsh
stuff we have now. Lots of digging out and replacing.....good idea?

What you propose will create an interface between top soil and subsoil.
Many plant roots will not cross that interface.

Instead, start by applying a generous amount of gypsum (calcium sulfate)
to the area. (I don't know about its availability in England, but I can
buy a 50 pound sack for US$9.) Water it lightly. If you don't get any
rain, water it again more heavily in about 3-5 days. Repeat rinsing the
gypsum into the soil ever 3-5 days if there is no rain. Gypsum will
dissolve and react with the clay to make it somewhat granular and porous.

After all the gypsum has disolved and rinsed into the soil, allow the
soil to dry for about a week. It should be moist in the top foot but
not wet. You might have to cover the area with a tarp while rain falls;
remove the tarp as soon as the rain ends so that the soil can continue
to dry.

When the soil is moist but not wet, apply your purchased top soil to a
depth of not more than a foot. Also broadcast a modest amount bonemeal
or superphosphate over the area. Using a motorized tiller, till to a
depth of 2 feet; this should result in an area more than a foot higher
than it had been (1 foot of top soil plus 1 foot of stirred natural soil
plus some air). You might want to hire a service to do the tilling, in
which case you will not hurt your back and you will not be liable if a
tiller blade breaks.

You will now have a 2-foot depth of well-prepared soil for planting.
Avoid walking across the area when it is really wet; otherwise, you will
undo much of the tilling.

Dress the area with more gypsum annually, about a month before the most
rainy part of the year. You will only have to wet down the gypsum and
allow the rain to rinse it into the soil. Roots will not find an
interface and will thus penetrate into the clay subsoil. With an annual
application of gypsum, nutrients added to the area will eventually leach
down into the clay, except for phosphorus. Phosphorus (bonemeal or
superphosphate) does not dissolve easily and must be placed where roots
will find it, which is why you apply that before tilling.


As an aside, we had our lawn put down 2 years ago, and only now over the
last month or two with some sunshine and lots of rain has it come back
to life as it were....was previously, quite thinned out especially when
cut and not really great looking - although fine when it looks like it
needs cutting, again due to the clay soil and poor drainage - but I do
throw down aftercut lawn care every so often when I mow it.

In terms of going forward and planting, what types of shrubs, plants,
flowers that are all year round, and keep coming back are best suited
for the environment I describe?

Thanks for the advice and recommendations in advance!!

Since I am not familiar with your climate, I cannot comment on lawn care
or recommend plants for you.

--
David E. Ross
Climate: California Mediterranean, see
http://www.rossde.com/garden/climate.html
Gardening diary at http://www.rossde.com/garden/diary