The pine bark used in soilless mixes is finer particulate size and is
composted so that most of the parts of the bark which are digestible by
micro-organisms are used up with only the hard to digest lignified parts
are left. The size of the pieces of pine bark are 1/4 inch or so and are
not the big chunks you find used for garden mulch. Having the bark
composted serves two purposes: it assures that there is very little
matter left for microbial decomposition, (a process which can use up
nitrogen that your plant might like to use); and it gives you a stable
soil particle that supplies the soil mix with aeration and drainage that
won't easily break down into mush or slime the way cocofiber will in a
mix.(The good thing about perlite is that it is inert and will not break
down over time under any circumstances) The organic constituents of soil
mixes will all break down over time, shifting the soil Ph (making some
nutrients unavailable) and changing the aeration pore spaces in the
soil.
Denis at Silver Krome Gardens
Cooper, Susan L. wrote:
>
> Can someone explain the pine bark to me? I've never quite gotten it clear
> in my mind...
> I thought folks put down pine mulch because "something" in the pine bark
> helps prevent weeds from growing. The explanation given to me was that not
> much grows in a pine forest (except the pines, duh) due to some inhibitor
> with the pine needles, or roots or ???.
> Am I just totally nuts or has anyone else ever heard this?
>
> If it isn't true I'll start adding a little pine bark to my mix, it is easy
> to find here (up north), people use it for decoration.
>
> Susan
>
> -
> pine bark. The bark may be hard to find in the north, but half or more of
> perlite to a peat based mix is better than the peat by itself.
|