Xtremehorticulture

Clover-Like Weed Not Clover, Difficult to Control

Q. I have reddish, clover-looking weeds that have taken over my lawn.  Last year they nearly covered it.  I tried weed and feed several times but that didn’t seem to get rid of them.  A friend of mine had the same problem and had to remove all of their grass and re-sod their lawn. They bought their own lawnmower made their landscaper use it because they said the lawnmowers that landscapers use can spread this clover everywhere. Readers picture of “clover” A. the picture you sent to me appears to be oxalis and not clover. Oxalis has a yellow flower. Clovers usually have white, pink or reddish flowers. They both have clover-like leaves.             Oxalis is extremely difficult to control once it gets established. We see them growing in flowerbeds and shrub beds as well as lawns. In beds, it is usually brought in with the plant material as a weed contaminant in the container. But it also can be brought in on lawnmowers. Oxalis Focus on weed killers for lawns that include the weed “oxalis” on the label rather than clover. If you are not sure, give me the name of the product in an email and I can help you from there. Control it now or in the fall, not during summer heat. If there were not too many, you could consider digging out the contaminated lawn areas to a depth of about 6 inches and replace it with sod. In your case it sounds like it’s covering the entire lawn. There are many different lawn weed killers labeled for controlling dandelions. They contain several weed killers in different combinations to control a different array of weeds. Look at “dandelion” weed killers but make sure the label includes controlling oxalis. Use a product that is sprayed rather than a dry granular applied to the lawn. Related links to this post http://xtremehorticulture.blogspot.com/2014/02/clover-looking-weed-with-yellow-flowers.html http://xtremehorticulture.blogspot.com/2012/11/this-clover-looking-weed-is-hard-to-get.html

Clover-Like Weed Not Clover, Difficult to Control Read More »

Clover-Looking Weed with Yellow Flowers is Very Difficult to Control

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. 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. 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. 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. 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!  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.  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.

Clover-Looking Weed with Yellow Flowers is Very Difficult to Control Read More »