On Sat, 31 Jul 2004 00:43:58 GMT, Vox Humana wrote:

"Hans L" wrote in message
...
On Fri, 30 Jul 2004 16:20:46 GMT, Pam - gardengal wrote:

"paghat" wrote in message
news In article , Hans L
wrote:

We have a small area next to the house (in the Cleveland, Ohio,
region),
where my wife has planted petunias for the second year in a row. It
gets
sun part of the day. Last year, the flowers lourished and eventually
covered the entire surface. However, before they had proliferated,
one
could see the hardened, dreary-looking soil. So this year, I added
mulch.
Looks great.

Now, the flowers did not expand at all this year, and a bush in this
area
died rather quickly at the beginning of the summer. A neighbor and my
wife
claim that it is the mulch that hampered the growth, and my question
is
if
this could be the case. It needs to be mentioned that we have had a
lot
of
rain this year, that there is no slope in this area, that the
humus/soil-cover is rather thin, and that there is clay underneath.

Thanks -- Hans L

If you used something like heavy straw for winter mulch, it has to be
removed near winter's end or early spring as it smothers stuff that is
trying to grow, & as straw too-slowly decays, it robs the surface soil
of
nitrogen. In some cases, an uncomposted bark can also rob the soil of
nitrogen.

But if you used a completely composted manure topcoating for mulch,
that
improves the soil & healthful microorganism populations, in addition to
protecting roots of things in winter & encouraging worms to work the
soil
a bit. Manure compost would not have stunted or stopped the growth of
anything except seedlings (a pure surface compost tends to be sterile &
it
is difficult for seedlings to get started through it, which is why
compost
topcoatings suppresses weeds, but not so good if seeds were
surface-sown).


I'd look elsewhere for the cause of problems. Unturned compacted soil
with
too little organic material in it, plus poorly draining clay soil
during
a period of heavy rainfall, would predictably stunt plant growth or
even
kill some of things outright.

This is entirely correct, however I would also add that the specific
type of
mulch can make an impact on the plants' performance. Mulches comprised
primarily of sawdust or very fine bark can reduce the available nitrogen
in
the top layer of the soil, which can result in stunted or or less than
optimal growth. This is more likely to be a problem with very shallow
rooted
and herbaceous plants like annuals and most perennials rather than
larger
and sturdier, woody shrubs and trees with deeper root penetration.
Simply
providing additional nitrogen rich fertilizer will offset this or use a
compost mulch in these areas.

Since you indicate a shrub has died off as well, I'd be more inclined to
agree with paggers that too much rainwater combined with the less than
ideal
drainage of heavy clay soil is most likely the culprit. This can be a
fatal
combination for the majority of plants.

pam - gardengal

Hello paghat the ratgirl & pam - gardengal:

Thank you for your insights. I have two followup questions:

- I added bark mulch because the soil, before the plants covered it,
became dry and hard as rock, looking aweful. The bark mulch (tinted black
in our case) makes the ground look nicer. What else, more beneficial to
the soil, could give the same effect?

- Is there any way to drain a flat area as ours? Digging up the clay and
mix it with sand? Or ...?

What is the possibility that the mulch was contaminated? I understand that
some bagged mulches can contain ground-up shipping pallets that are
contaminated with all sorts of chemicals that might have been in containers
that they supported.

Well, I have used it all over, and grass grows pretty well in the bark
mulch I have used.
Hans L