Killing Bermuda grass is not difficult, but it's not going to happen overnight. I'm a desert landscaper. I spend a lot of time killing lawns, especially Bermuda grass lawns, to replace them groundcovers that use less water. I have learned that no matter what the herbicide package says, it will take at least a month and several applications of herbicide to kill 90 to 95% of the Bermuda grass, then several months of spot application on surviving sprigs to get the remainder. It's a tough plant. It's so tough that it grows in the cracks of the concrete medians in the middle of a Phoenix freeway.
|Bermuda Grass with seed heads|
By Harry Rose from South West Rocks, Australia via Wikimedia Commons