Re: grass clippings as mulch
- To: m*@ucdavis.edu
- Subject: Re: grass clippings as mulch
- From: d*@ilsham.demon.co.uk
- Date: Tue, 29 Jun 1999 21:21:59 GMT
- References: <37787E4E.52D2@cgac.es>
Damian wrote:
>Can anyone comment on the relative benefits of raw grass clippings as
>mulch? I have recently started experimenting with it rather
>enthusiastically, mainly to give protection from heat and fierce sun to
>my last round of native plantings in our wildlife garden (wild olives,
>tamariscs, carob trees, figs, arbutus, wild almonds). Another benefit is
>water retention for our rather poor sandy soil.
If the soil is already moist before spreading the clipping, they act
as excellent moisture retainers, however their use is not without
problems. If they piled too thickly and 'pan down' becoming too
compacted, they will heat up rapidly as a result of anaerobic
bacteria, creating a slimy mass which further needs to take valuable
bacteria from the soil in order to break it down to a nutritious
mulch. Effectively they de-nitrify the soil temporarily and can in
extreme cases, cause temporary deficiencies in growing plants at a
critical time in their growth cycle. Ideally the clippings should be
dried before spreading and only spread to a depth of around 2 inches
maximum.
> I have recently lost some newly planted Celtis
>australis and I haven't ruled out "pressure cooking" of the roots due to
>an unwise combination of grass mulch, water and excessive heat. But, as
Sounds very much like it Damian, here in the UK it is best used
sparingly and most gardeners make a compost heap, piling it in 6" - 8"
deep layers, interspersed with other vegetable matter and a bit of
soil. Provided the heap is kept lightly moist, an excellent,
retentive and highly nutritious compost is formed within about 3 - 4
months in summer and the heating caused as the bacteria set to work,
usually kill the majority of weed seeds.
Dave Poole
TORQUAY UK
