The aim of mulching is not usually to kill all the weeds but to reduce them to the sort of
level that is easy to live with. In fact, the presence of a few weeds increases the diversity of
the garden ecosystem and is thus very good for the health of the garden. Deep rooted ones,
like dock and dandelion, bring up minerals from the subsoil. It can be worthwhile simply
to chop off the leaves of these plants and use them as a nutrient-rich mulch, leaving the
roots intact as a nutrient pump, rather than digging the whole plant out. Other 'weeds', as
we have seen, are edible.
Weeds that send out runners, such as couch and bindweed, may not be killed by the
mulch. But they tend to grow more between the mulch and the soil than in the soil itself.
So at the end of the growing season you can just pull back the mulch and scoop up the ma-
jority of the roots without any digging.
In an established garden any organic material, like grass mowings, leaves or shredded
paper, can be used as mulch between the plants. It can virtually eliminate weeding and save
as much as 40% of watering requirements by preventing evaporation from the soil.
Slugs can be a problem with mulch - as they can without it! So it may be necessary to
withhold the mulch for a while in wet weather when the plants are still young. A way of
controlling slugs is to dig a pond and stock it with frogs, or to keep a few ducks which
can be let into the garden now and then, both of which love to eat slugs. (Chickens should
only be let into the garden for tractoring, as they make a real mess of the mulch.) Perenni-
al plants are hardly troubled by slugs, as they do not have to pass through the vulnerable
seedling stage each year.
The Forest Garden
One of the best examples of a permaculture garden is the forest garden developed by the
late Robert Hart of Shropshire. It has the layered structure of a natural forest: a canopy of
fruit trees, a lower layer of dwarf fruit trees and nut bushes, a shrub layer of soft fruit, a
layer of perennial herbs and vegetables at ground level, plus root vegetables and climbers.
The total production of this garden is greater than a monoculture of any one of its layers
could be. This is partly because of the beneficial effect of such diversity on plant health and
partly because the forest garden makes the maximum use of the resources available to it.
It makes the most of the sunlight available to it because the different layers come into
leaf at different times of the year: the herb layer first, in the early spring, followed by the
shrubs, and lastly the trees. Throughout the growing season there is something at the peak
of its growth, making the most of the energy available from the Sun. This is something that
does not happen in a single layer planting, whether of trees, shrubs or herbs. Exactly the
same sequence can be observed in a natural woodland in our climate.
Maximum use is made of the whole volume of the soil because the roots of the various
plants in the garden feed at different depths. In this way the stacking of different layers
above ground is reproduced below ground. Some of the plants present are particularly good
at accumulating certain plant nutrients from the soil, and they contribute this to the others