Here’s a different way of controlling the Bermuda grass that gets into your garden and invades the St. Augustine grass lawns.
This is called Solarizing. By placing clear plastic over the Bermuda at least 2′ beyond the stolons, sunlight can not reach the grass. According to the LA Times, shallow cultivating may also help. But do not cultivate more than 3 ” deep, as this will bring the seeds into the top soil layer.