Q.how to conquer invasive cloverlike plant?
There is an invasive plant in Houston which spreads primarily through corms, somewhat resembles clover and loves to put their corms right under your favorite plants. If you dig them out [there are millions of them] and split a corm you will have multiplied the next crop. I have hand dug and removed thousands, put down weed barrier, topped with mulch and thereby temporarily slowed the progress of this evil weed, but know in my heart it will return with a vengeance. BTW the flowers are sweet little pinkish purple viola like clusters. Thank you.
Certified GKH Gardening Expert
These are called oxalis. They can be eaten raw, and resemble a very sour grape. Their flowers give way to exploding seed pods that make these impossible to control.
You will have to pick them all up before they put out flowers for several years. This will stop the new seeds from sprouting. Dealing with the root nodules underground will be very tough, though.
You will have to remove everything from that plot, and sterilize the area with boiling water. This will remove anything in the soil, including you plants that you intend to keep.
This is an unfortunate problem with not so many good solutions.
These links discuss the control of Clover's.
Since you don't have an id for sure of the weed, I would call you County Extension Office for an id and their suggested method of control.