Q. I have oxalis clover look-alike as a weed. How can I control it? I am
ready to use chemicals at this point having tried to rid it by digging and
pulling with no success. Having it in my grass is bad enough but now that it is
in my iris beds I want to kill the dang stuff!
 |
| Oxalis looks like clover but has yellow flowers that resemble a daisy with only five petals. |
A. Oxalis is very difficult to kill. It may require
repeat applications but one of the keys is to try to kill it when it is “happy”
and is ready to grow and multiply. This is usually spring and fall. Go to your
favorite nursery or garden center (you may have to look at several such as
Lowes, Home Depot, Star and Plant World). Go to their weed killer section. Look
at the active ingredients. Look for the following in the active ingredients
list.
repeat applications but one of the keys is to try to kill it when it is “happy”
and is ready to grow and multiply. This is usually spring and fall. Go to your
favorite nursery or garden center (you may have to look at several such as
Lowes, Home Depot, Star and Plant World). Go to their weed killer section. Look
at the active ingredients. Look for the following in the active ingredients
list.
The important chemicals to find on the label are either
Dimethylamine salt of dicamba: 3,6-dichloro-o-anisic acid (it may be just
called dicamba or Banvel) somewhere on the label.
Dimethylamine salt of dicamba: 3,6-dichloro-o-anisic acid (it may be just
called dicamba or Banvel) somewhere on the label.
The alternative would be an ingredient called triclopyr, (chemically called 3,5,6-Trichloro-2-pyridinyloxyacetic acid)
These chemicals are usually combined with other weed
killers for better synergism (efficacy or improved performance). In cases of
herbicide synergism 1+1 = 3 times more effective. So you may see 2.4-D listed
as the first chemical (Dimethylamine salt of 2,4-dichlorophenoxyacetic
acid) or you may see 2,4-DP (mecoprop or Dimethylamine salt of
(+)-(R)-2-(2 methyl-4-chlorophenoxy) propionic acid) listed as well on the label but the names in
RED are the most important for oxalis control.
killers for better synergism (efficacy or improved performance). In cases of
herbicide synergism 1+1 = 3 times more effective. So you may see 2.4-D listed
as the first chemical (Dimethylamine salt of 2,4-dichlorophenoxyacetic
acid) or you may see 2,4-DP (mecoprop or Dimethylamine salt of
(+)-(R)-2-(2 methyl-4-chlorophenoxy) propionic acid) listed as well on the label but the names in
RED are the most important for oxalis control.
I am sorry for the detailed technical response but this
is really technical stuff to get you the right chemical. There are so many different manufacturers
and labels with the same stuff in it, it is impossible to list them all so
giving you the ingredients to look for is much easier.
is really technical stuff to get you the right chemical. There are so many different manufacturers
and labels with the same stuff in it, it is impossible to list them all so
giving you the ingredients to look for is much easier.
Next is the method of application. These chemicals will
not damage a lawn if you apply at the right concentration but they WILL damage
other plants. So you must spray them directly to the weeds and
not overspray onto other plants!
not damage a lawn if you apply at the right concentration but they WILL damage
other plants. So you must spray them directly to the weeds and
not overspray onto other plants!
Make
sure you wear waterproof gloves when mixing and applying and wash thoroughly
after an application. They are not THAT toxic but it is always a good
precaution. Never spray on a windy day. Spray when weather is warm but not hot
because the plants are better able to “absorb” the spray.
sure you wear waterproof gloves when mixing and applying and wash thoroughly
after an application. They are not THAT toxic but it is always a good
precaution. Never spray on a windy day. Spray when weather is warm but not hot
because the plants are better able to “absorb” the spray.
Mix about 1 tsp of
ivory liquid detergent per gallon of spray to the finished mix and thoroughly
stir it. Do not add it before you add water or it will just
give you a lot of weed killer bubbles. This detergent helps the week killer
enter the leaves.
ivory liquid detergent per gallon of spray to the finished mix and thoroughly
stir it. Do not add it before you add water or it will just
give you a lot of weed killer bubbles. This detergent helps the week killer
enter the leaves.