Lawn Weeds - Oxalis
Oxalis is considered a weed. It appears in late September in lawns in the Mediterranean. Be warned Oxalis does kill everything underneath it. So when it disappears around April time, you are left with dying Oxalis and no grass. |
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Oxalis (Oxalis corniculata L.) is a perennial herb that is considered a troublesome weed in many lawns and gardens. This broadleaf weed also known as creeping woodsorrell, has clover-like leaves with yellow, purple or green flowers when in bloom. 4) Our herb-ono granular and
pre-emergence weed killer (see lawn
care products,) applied during the growing season of the Oxalis can
substantially reduce its numbers, but will not eradicate it. The first application will turn the
colour of the oxalis leaves to a much lighter green. The second
application after 3 - 4 weeks will see the leaves curling and
starting to turn yellow or brown. 5) If you do nothing, oxalis will flower and multiply very quickly
and take over your lawn. Do not let it flower. 6) You should also mow your oxalis regularly in the winter to keep
the oxalis leaves from cutting out the light from your lawn, which
will ultimately kill the grass during the growing season of the
oxalis. 7) Before applying any weed killer treatments, make sure you have
surviving grass below the oxalis, otherwise when the oxalis dies you
will think that the weed killer has killed the grass as well. If you
find there is no grass in your oxalis patch then you will have to
re-seed or re-plug the lawn BEFORE applying any weed killer, otherwise
you will have brown soil bare patches in your lawn when the oxalis is
dead. Combinations of treatments 1), 3) and 4) will solve your oxalis problem over a
couple of seasons.
Oxalis should never be left to get established or flower as this prolongs the eradication into another season. So once seen should immediately be eradicated. A few oxalist plants indicates dosens of seeds that have not yet germiated.
Oxalis in the Mediterranean starts to appear in or around October when
the weather is cooler and the soil moisture increases, and starts to
die back and turn yellow in April. Oxalis spreads throughout the landscape by spreading at the stems from the roots and through the vast production of seed. Although oxalis can be difficult to kill, methods are available to keep this weed under control.
Here
are some Oxalis control options for you ...
1) One method is to apply pre-emergence herbicide before the Oxalis
appears in Autumn. You can use a handheld spreader for gardens or small
areas of turf. You can purchase pre-emergence herbicides at home improvement and hardware stores or local
nurseries, but be careful as some will also kill the lawn. We have a
tested herbicide that will kill oxalis in lawns - see products
page for details.
2) Pull out any emerging oxalis by hand. This is a difficult one,
especially in a lawn. Some oxalis may grow in the lawn or garden despite pre-emergence herbicide treatment. The best
way to prevent spreading is to pull each weed out entirely with the root.
3) Apply our Lawns in Spain "Oxalis Killer" herbicide as necessary during the growing season.
If using concentrated herbicide, mix with water in a garden sprayer according to the
directions. Be careful when applying non recommended broad leafed weed
killers as some will also kill the grass.