We have St. Augustine close to the house and trees and big patches of Bermuda grass in the rest of the yard (this had been planted by previous owners of this property.) It is a constant battle to keep the Bermuda from spreading into the St. Augustine and into the vegetable and flower gardens. In the summer, after a good rain, I take a garden fork and lift the soil (and sometimes turn it over) where the Bermuda grass is so that it will dry out and the grass will be easy to pull the next day (since it is dieing). Digging and hand pulling is the only thing that has worked for me in the St. Augustine areas. It's a lot of work but worth it to keep the B. grass from taking over. However, in spots in the back yard where I want to kill large patches of B. grass, I use leftover pieces of sheet metal from our shed. The metal sheets are green so they aren't too noticeable and they absorb heat quite well. Everything under where the sheet metal is laying gets "cooked" and I just pull them over to a new spot after a week or so to kill another patch of the evil Bermuda grass. (lol)
My husband helped me build a run (long fenced in area) all around our vegetable garden which is connected to our chicken's yard. They love to scratch and also eat grass which helps slow down the grass trying to creep into the garden. Sometimes when we have had a lot of rain I have to use the weedeater in the run and take a hoe or garden fork to the B. grass to get it under control again. Usually the chickens are very effective in keeping it out, though.
There are large areas of various native grasses on our property and we are trying to keep the Bermuda from taking over that, but it is very difficult since it spreads so fast.
