On 06/10/2013 21:10, Jake wrote:
On Sun, 06 Oct 2013 19:51:24 +0100, stuart noble
wrote:

On 06/10/2013 19:01, Jake wrote:
On Sun, 06 Oct 2013 18:51:23 +0100, Chris Hogg wrote:


If I have old compost I either put it on the compost heap, of if its
texture is not too bad, mix it with an equal amount of fresh compost
and add a little slow-release fertiliser, either synthetic such as
Osmocote, or organic such as blood, fish and bone.

If you have borders as well as tubs, it's often the case that
perennials will benefit from some winter protection. When I empty my
tubs/planters/baskets at the end of the season, the plants go on the
compost heap and the compost goes on the borders. It'll provide that
bit of protection for the plant stumps and, with the effort of the
worms, will improve the soil structure.

And it's not at all odd that after 20+ years of doing this, my borders
haven't risen a foot or so!


I can't fathom this. When bought compost has been used for a year, what
is it you're left with? Whatever it is, we are told it has no nutrients
to speak of, yet eventually it breaks down into something that occupies
no space.
I re-use the same compost in my containers with no appreciable reduction
in fertility. Yes, I mix in a bit of chicken manure when re-planting in
the spring but sometimes I wonder if even that that is essential. My
impression is that there is plenty of nutrition left in the decomposing
organic matter, but of course I have no scientific justification for
that :-)

And I can't fathom your argument, sorry. When we buy a bag of compost,
it will comprise all sorts of inert stuff with the added bits and
pieces that turn the inter stuff into something that will sustain
growth. Don't forget that peat is essentially a nutrition-free soil
conditioner! If you look on the compost packs you may see "feeds for x
weeks".

Plants will find and (cos that's what they do) utilise whatever feed
there is in the compost. But hang on, you reuse the compost with no
appreciable reduction in fertility having added chicken manure which,
of course, replaces the feed that plants took from the compost the
previous year. Doh (sorry)!

No need to apologise! I'm far from consistent with the chicken manure,
and I can recall plenty of instances where supposedly nutrition free
material has turned out to be very productive. I even remember a bumper
crop of King Edwards that were grown in supposedly spent B&Q compost
from the previous year's troughs.
I wonder what the "inert" stuff in peat free compost might be, and what
the "bits and pieces" are that turn it into something that "sustains
growth". I would have thought inert material wouldn't decompose or
sustain the plants.