Re: Soil care (roots)

Marina & Anthony Green wrote:
> 
> I have an area in my garden which has a few rather weedy herbaceous plants, on which nothing that I
> attempted to sow (nothing extravagant, just Alyssum, parsley etc.) would grow, and most of it didn't
> even seem to germinate, but in pots in the same area they did.
> So of course I dug up a square metre of soil and found that it is absolutely choked with roots, so
> that the volume of fibrous root which I took out was almost equivalent to the volume of the soil! I
> imagine the previous owners just never dug it over, so we could be talking 30 years of roots!
> I have been told that this dead root material makes the soil far more acidic, and was clearly stopping
> any development of plant life.
> I am wondering whether to sieve the soil because it is so choked. Do I need to be so conscientious
> about removing existing roots? Even if I spend an hour on one small square, every time I pull up a new
> forkful of soil there is new root material to remove, and at this rate it will take until Christmas to
> dig it over as I'm doing at the moment!
> Any ideas or experience of this sort of thing?
> 
Anthony
My first reaction is to ask "what is producing the roots, and are you
sure anyway the roots are actually dead?". Massive amounts of roots
nearly always indicate the presence of some large shallow rooted tree in
the neighbourhood, which many in fact be an astonishing distance away.
Once I was called in to determine the origin of masses of roots which
were invading a vegetable garden and after a good deal of detective work
traced them to an elm tree in the neighbouring garden  at least 16
metres away! Elms are notorious for this and Japanese Cherries are
equally bad. No doubt there are many others with similar habits.

If the tree has been cut down in recent times and the roots are in fact
dead, I am astonished they are not well on the way to rotting down.
Unless the soil is waterlogged this would only happen I think if the
ground is very short of living organisms so that normal recycling is not
taking place. Such a soil would indeed be hard to grow things in.
Normally in any live soil dead roots  rot quickly and being well spread
through the soil profile are a particularly valuble source of humus. If
they really are dead, It seems that what your soil needs is really some
manure of compost to accelerate the rotting process.

I can't see anyway how dead roots which are NOT rotting could influence
the pH. The reverse could I suppose be true that the roots are not
rotting BECAUSE the soil is already acidic. There  is also a faint
possibility what is causing the lack of growth in the area is some sort
of allelopathy (ie poisoning) as a few types of tree roots ( apple and I
think ash, for instance) when rotting can produce such chemicals.

However, in the absence of evidence to the contrary, my inclination is
to believe the root mass does belong to some live tree which is simply
using the entire soil for its feeding and making it very difficult for
anything else to get a toehold in the area. If this is the case your
labour of clearing may be in vain as the tree will alnmost certainly 
soon regrow with vast enthusiasm and reoccupy its territory.

Where there is a massive concentration of live tree roots, there is not
only fierce competition for food but even more for moisture and that is
most likely why seedlings are unable to estabish themselves.

 Such a situation is pretty difficult to deal with effectively if you
want to grow things unless you can get rid of the tree causing the
problem, or block it off from the area by putting down barriers in the
soil. Your best strategy might be to put a thick layer of newspaper or
cardboard in the ground and then top this with a mix of compost and soil
to create a raised bed in which you can plant. Hoever, I do warn you it
may not be long before the roots fight their way through the barrier to
help themselves to all the nice new food!

Alternatively, this might be a place for standing plants in containers.


Moira
-- 
Tony & Moira Ryan,
Wainuiomata, North Island, NZ.     Pictures of our garden at:-
http://mywebpages.comcast.net/cherie1/Garden/TonyandMoira/index.htm
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index