Mulching Your Organic Garden
A Mulch is a protective covering of the soil surface. It
moderates summer & winter temperatures by insulating the
soil
from
extreme heat & cold. It also prevents erosion, assists retention
of soil moisture, improves soil structure, helps keep crops clean
& disease free, encourages earthworm activity & acts as a weed
barrier. When mulches are made from organic materials, they will
gradually add to the soil organic matter & nutrient bank as they break
down. Be aware of the need to partly compost or water down animal manures
as a mulch...
An example of mulching: partly
composted Hay has been used here. Second photo below.
You can use several different materials as a Mulch...
Compost - Excellent to use,
provides great nutrients, though it is usually too valuable for use as a
general mulch material. J
Well-Rotted Manure - As
above, we use it fairly regularly as it provides considerable amounts of
nutrients (whereas leaf mould provides fewer) but don't use fresh manure too
close to the base of the vegetable, as it can
burn plants.
Hay - A very good insulator,
good nutrients, rots well, but be sure of your source, as it can introduce
annual weed seeds.
Straw - Longer lasting than
Hay but not such a good weed suppressor. Watch out for commercially
produced straw, as it may contain residues of chemical weed killers; partially
rotted Straw is much preferable.
Leaf mould - Looks very
attractive & provides some nutrients to the soil, but does so slowly. (also good for leaf fights!
)
Try to avoid street swept leaves which can have a high lead content.
Peat Moss - Slow to
decompose & is very acid. A non-renewable resource so it can be
environmentally unacceptable.
Newspaper/Cardboard - Very
useful under biodegradable mulches to improve weed control. You can also
use it as a good base for a new garden to provide a weed mat &
nutrients. Watch out for slugs & snails hiding under it ~ they love
it!
Lawn Cuttings - Usually
available in large quantities, though be aware of recent herbicide use if
bringing it in from outside your land. I've found that lawn clippings
(even kikuyu grass) provide good weed
control when applied regularly, & nutrients for your garden as it
decomposes, but be aware of the need to top-up with other nutrient-rich
additives, like compost/other mulches etc, over the long term. Watch out for annual weed seeds also.
Hardwood Sawdust - Safest to
use when weathered for several months spread on paths etc. first, otherwise it
can cake & repel water. Sawdust will cause nitrogen deficiency if dug
into soil, so use sparingly.
Mushroom Compost - Great
material, but use only organic mushroom compost, as high levels of pesticide
residues are likely to be present in commercial supplies.
Forest Bark - Longer lasting
than most materials, though sometimes slow to decompose, depending on the
various grades. Phenols & tannins in the mulch can contribute to weed
control, as well as pest & disease control!
To place a Mulch on your
Garden: simply collect your choice of
materials, & depending on the size of your plants, gently lay between 5-20
cm (6-8") deep mulch all over the soil. Mulches should be kept clear
of the stems of plants where rotting is likely to occur, but in some cases such
as Tomatoes, Potatoes, Rosella's, & Brussels Sprouts, plants will make new roots into
the mulch placed around their stems, resulting in stronger, more vigorous
plants! Repeat this procedure when the mulch wears thin, & dig into
soil after the crop comes out - it's brilliant!
Our Organic Garden after
mulching - the growth & health is spectacular
See also: Organic
Sprays
