APPROPRIATE INGREDIENTS > GROWING
YOUR OWN INGREDIENTS > GROWING
VEGETABLES > WEED CONTROL
How to control the weeds
in your garden
& MAGS THE NATURAL FOOD HUB
Weeds get in the way of
our gardens. They are simply life on earth trying to 'be', and I
they could be regarded as a testament to irrepressible 'life force'
by some as DNA!). But most of us would be a lot happier without them.
We can never win the battle
weeds, but we can reduce their impact to very low levels.
How we manage weeds depends
how dry the climate we live in is, how big our vegetable garden or
is, how much time we have, what tools are available to us, and what
we have to do what needs to be done when it most needs doing.
Managing a vegetable garden
different from managing a yard full of fruit trees which is different
managing a lifestyle orchard. So we will consider these separately.
This page is written to
home food gardeners, and practices are quite different to those
to commercial garden and orchards.
It is also written with the
that most of us would prefer to use the chemicals known to be very
from a human health point of view.
The most important thing to
in mind is that there is no one thing that will 'do it' for every
garden situation. Usually, a combination of strategies works best.
'One years seeding
years weeding'. This pithy little saying is unfortunately largely
Even one plant of some of the worst weeds will produce thousands of
to multiply the weed load in the following year. If is feasible, get to
the weeds BEFORE they mature seeds.
Disturbing the soil is
as sowing weed seeds. Weed seeds can remain dormant in the soil for
decades. When the soil is dug over, the exposure to light stimulates
Either avoid unnecessary digging, or be prepared to deal with the
swathe of seedlings.
'Prevention is better
Another irritating truism. But how true! One home grown plant from
or family can bring with it bulbils of intractable weeds like oxalis
or pieces of persisistant rhizomes such as couch grass. Check the
mulch materials-you bring onto your property for persistent weed bulbs
Striking at the right
save time later. For example, spraying newly emerged seedling weeds
will wipe out swathes of potentially large plants that are more
to spray later, and that take more time and more material to spray
Hoeing on a hot day is very successful; hoeing in showery weather is
successful because some weeds will re-root in the moist conditions and
will have to be later attacked again .
Most of us are summer
This means that the veggie patch is often left over winter, and becomes
a weed patch - nature abhors a vacuum.
Managing weeds in the veggie garden
In spring, the choice is
'digging the weeds in' or spraying them out. Which works for you
on several things.
First, your belief about
The best herbicide to use from the point of view of a home gardener
to be certain to effectively kill all the different kind of weeds AND
no risk to personal health is to use a glyphosate weed killer (the best
known brand at this time is 'Roundup' produced by Monsanto). This
to be a practically safe chemical when used as recommended.
Second, whether or not
will endanger adjacent plants. Glyphosate may be very safe as far as
are concerned, but it is deadly to plants. If there are precious plants
hard up against the veggie plot, then you run the risk of damaging or
them if you spray close by.
Third, timing. Often, today's
the day. The day on which the veggie garden has to go in. You buy your
transplants and fertilizer, dig the garden so the weeds are buried, put
in your plants-job done.
Fourth, improving the soil.
Few of us are blessed with light, free draining, fertile sandy, peaty,
or volcanic loams. Mostly, we have to dig in lime, dig in peat, dig in
compost, and physically break up the soil to improve the drainage.
Establishing a new veggie
Using glyphosate is a very
option, and often the only realistic option, for clearing an area of
or weeds for a new veggie patch.
Preparing an existing
garden for spring planting
For those of use who are
summer gardeners, glyphosate is a very good option for 'cleaning up'
existing veggie patch in preparation for the new season. This is
important where there are weeds such couch grass and kikuyu grass which
spread by underground rhizomes.
The most effective method in
warm temperate and warmer areas is to spray out once in winter, and
when the first flush of spring weeds emerge, just prior to the big
plant-up. This prevents winter seeding weeds making their deposit!
Spraying between rows of
Possible, but not for the
hearted! Glyphosate is dangerous to all plants, and it doesn't
between friend and foe. Lapse of concentration, sudden gusts of wind,
and carelessness can cause you to damage or kill the produce of which
are so justifiably proud. This is high risk territory - almost
to males, in other words! In our opinion, glyphosate is too risky to
as a between row weeder in a home garden of mixed veggies. There are,
always, exceptions. For crops which have waxy, water repellent coatings
on the leaves, such as cabbages, broccoli, other brassicas and crambe,
you can often get away with spraying between the rows WITH a spray
USING a lower rate, and WITH GREAT CARE.
First, on available evidence,
there is no risk to human health, immediate or carcinogenic, from using
glyphosate in the ordinary manner. And probably not even when used at
higher dosage. It works on a plant specific enzyme system, and seems to
be well proven as safe for animals when used on weeds.
The real risk is what is
called 'collateral damage'. That is, plants you love and hold dear get
a drift of glyphosate and are severely damaged or die. This can be
by 'the bounce', 'drift', 'the drip' or carelessness.
To repeat, between row
with glyphosate in the home veggie garden is a high risk activity, and
you really have to have killed a few plants and had had quite some
to know what can and can't get away with. It is not recommended for any
but the most experienced. The winter/spring spray-outs are safe as long
as risks are minimized-
droplets can 'bounce' off
soil and onto adjacent precious plants.
a fine mist can be carried
onto precious plants nearby
it is not uncommon for
to leak at the hose or the nozzle. Each drip is potentially lethal to
plant it drips on
'mans work'!), like to push the envelope. It is always tempting to
as close as possible to precious plants to minimize later 'around
plant weeding'. Carelessness or a lapse in concentration can have
don't edge your veggie
lavender or the like. Use non-living edging. (if you must edge
lavender, AND insist on using glyphosate, use 'English' lavender, Lavendula
vera, as it has a quasi dormant period in winter and is less likely
to be damaged vs winter active species such as L.stoechas)
use a 'spray guard' on the
your sprayer to minimize 'bounce' and 'drift'. AND be careful to keep
spray guard close to the soil as you spray.
Use a nozzle that produces
droplets that are less likely to drift.
NEVER spray when there is
(virtually invisible to the naked eyes, by the way) particles drift on
even a breeze (use the right nozzle as above), but bigger droplets,
will drift in wind. Pick a calm day. Early morning can be calm -
in areas subject to coastal breezes.
Check your sprayer for
leaks - and
Use low pressure to keep
size large and less likely to drift. The higher the pressure, the more
Don't take risks! Remind
of the anguish and unhappiness that will result from an impulse to edge
that 'little bit closer'.
Use a dedicated sprayer
As long as you clean the sprayer THOROUGHLY, you can use it for
(if you are that way inclined), fungicides (ditto) AND glyphosate - but
it is high risk. In the real world, we get distracted, we mean to 'do
later' and all the rest. Play safe - have a dedicated sprayer for
Consider lowering the rate
spraying close to precious plants is unavoidable. A proven trick is to
halve the rate, but add a couple of dessert spoons (the amount is
of urea to each 14 litre/gallon and a half approx knapsack sprayload
a teaspoon to the gallon/4 and a half litres). This ultimately is
as effective as the full rate, but takes longer to see a result.
and this is the important point, it is less likely to cause damage from
Hoeing is extremely effective
the surface of the soil has dried out a little, the hoe is sharp, and
rows straight. Hoeing works best in a mulch free environment, perhaps
a follow up to a sprayed out 'no dig' type garden.
Perennial weeds are
and all. Hoeing is ineffective on some weeds that can re-generate from
the roots. Glyphosate takes care of this problem.
Digging can be confined to
row where you want to put in your transplants. For example, once the
is sprayed out, you could dig a row of the length you need
fertiliser and soil amendments such as peat, compost or sand), but only
one spades width wide. The area between rows can remain undug. Slow
palletized fertilizer can be spread on the undug soil surface over the
expected root run of your transplants. This saves physical effort.
But more importantly, it
the organic matter content of the undug portion of the soil is
Digging oxidizes organic matter. Organic matter can still be
into the soil by using mulches on the undug portion. The worms do the
Minimizing digging means
weed seeds are triggered into growth, meaning less work
A small garden knife -
with the handle painted bright red so it doesn't get lost (!) - has to
be used to clean up the weeds close in to the stems of the plants where
it is too risky to hoe.
The best time to hoe is
the latest crop of weeds are at the small seedling stage, and the day
sunny and/or windy. Conversely, the worst time is when the soil is
the weather rainy, and the weeds well advanced.
The twin dangers of hoeing
The best type of hoe is the
whose blade runs just under the surface of the soil, neatly severing
at the soil line. The most critical aspect is buying a hoe whose blade
is adjusted so that you can stand fairly upright as you work. A hoe
the blade attached at the wrong angle, or with too short a handle, will
force you to bend over as you hoe, causing unnecessary back strain.
Mulching is an excellent
where you can lay your hands on a sufficient quantity of material. It
excellent to put on after spraying the garden out for the summer crop
it suppresses summer weed seed germination AND conserves water.
risk taking-hoeing too
the plants in the row and felling the work of weeks in the blink of an
careless or inattentive
and slicing your finger open
Types of mulch
All these materials can
used under young home orchard trees. The bark of young trees is
to spray damage until it thickens up. Propietary plastic sleeves are
to prevent damage.
you can't fertilize during the growing season, a fiddle to put in, only
useful for one season for various reasons. Total weed suppression,
warm the soil, conserves moisture initially.
Woven weed mat-difficult
impossible to fertilize during the growing season, relatively
requires lots of wire pins to prevent lifting. Total weed suppression,
permeable to water, warms the soil, conserves water, will last around
years, maybe more if it has a mulch on top to protect it from the sun.
Sawdust-very good if
but it tends to crust, is difficult to get water thru. As it ages,
will germinate in it. It doesn't 'rob' the soil of nitrogen if left on
the surface, but certainly does if dug in. Clean, easy to handle. It
be untreated sawdust, not treated!
Hay- don't use it. It is
full of grass and weed seeds.
Straw-this is what is left
wheat or pea plant or whatever after the seed has been knocked off. It
is essentially weed free, has good weed suppressant qualities if
to about 100mm/4 inches thick, conserves water, builds organic matter.
It is also hard to find and bulky.
Newspapers-very good if
least 4 pages or so thick, when they will last about a year before the
worms and weather have destroyed them. Wet them as you place them, or
will end up chasing them all over the yard. They will need additional
such as lots of grass clippings, or sawdust or bark on top, or they
simply blow away when they dry.
Post peelings-last about
are good for putting over newspaper, but are bulky. Sometimes they
weed seeds from the forestry ground where the posts were peeled and the
peelings stored for cartage.
Bark-the best topping for
woven weed mat, or even put over sprayed out ground. It is expensive,
it will last four or five years.
Freshly pulled out
fine as long as they are not seeding and as long as they are well
However, they break down very quickly, and those on the bottom may
chipped plant material -
as long as there are no seeds in it.
A real problem spraying under
the canopy of young trees can be solved by using homemade or propietary
'weedmats' to suppress weeds right up to the trunk, at the same time
product is made from sheeps wool, and eventually breaks down, but
before the young tree has become well established in a weed free
Control in Home Gardens- J Mississippi
State University publication 1580, a brief fact sheet discussing
1999, 2000, 2003 UHIS