Question
My name is Norman Munsey and I'm a project manager for a general contractor. We had a project in Southern Arizona military base to install xeroscape in a established housing area. We excavated 3 to 4 inches through the site and pre-emerged with Surflan. We covered the area with a 6 oz geotextile fabric and the covered with a 1/2" rock material. We are to spray a post emergent surflan. The govern ment is questioning the preemergent for the area. There was broad leaf weeds and Bremuda comming out. Keep in mind this is a housing area that has been on base for about 30 years with established grass. What do you recommend as far as the weed control. We feel the government specifications are inadequate.

Sincerely,

Norman Munsey


Answer
Hey, Norman.

Using pre- and post-emergent weed killers is one way to go, but I think that's too much chemical in the environment. What I have done many times, and successfully, is a threefold process where grass and/or weeds have been prevalent:

1 - Pull up all the grass and weeds, as much as possible.
2 - Spray something like Roundup at the recommended strength. Let sit for at least three days before planting any plants.
3 - Cover the area with weed fabric and rocks.

The Roundup will kill most everything there. Then the weed fabric will prevent anything from growing up through it, resulting in no sunlight for anything that the Roundup doesn't kill. So ultimately what isn't killed by the Roundup will die from lack of sunlight. Then, with the half inch (or more) of rocks, little if anything will be able to get a good foothold and grow, making what does start to grow very easy to pull up.

Note that Bermuda grass can go quite a long time, and grow quite a long ways, underground with no sunlight, but it is also quite susceptible to Roundup in my experience.