Recently I converted to organic lawn care. My lawn is relatively weed free except for one area that has some crab grass. After digging these weeds, and also some of the St. Augustine grass with it, I took a section of 2" PVC pipe about 6 inches long, placed it on the core of the crab grass and sprayed "Round-up" (ugh) on them, through the pipe. This worked like a charm, and all the weeds are on their last leg. I would assume that the inner cardboard core of the used roll of toilet tissue would work as well.

I hope that the only bad effect will be the sterilization of the small amount of soil around the roots of the plant.

Oh NO! He said "ROUND-UP"

Patty

Crab Grass (cg) infestation is now horrific in the hill country North of San Antonio. Our augustine yards were virtually killed off in heat wave & drought of 09. I have mix of 60% augustine, 20% crab grass & 20% "other" (weeds & bare dirt). I'm on a gently-sloping quarter acre lot with minimal tree shade (20-30%). Hard rock 18" down ...

What I've tried: Vinegar + molasses weed killer from GardenVille. It yellows the cg & then cg comes back with a vengeance if I don't keep spraying it. I note other writer's idea of Round Up thru a tissue tube. Anything else to consider? ... Thanks in advance: BC

Hi bradco. Yes there is an alternative to Round Up for killing crabgrass, bermuda, and dallis grass in St Augustine. I replied to your similar question on the lawn forum. Click here to read it.

The ultimate answer is to not let the lawn die. I saw this coming last year as the average San Antonian let their lawns go. Had they followed the local watering restrictions, they would not have lost their lawns. This year most of the former St Augustine lawns are cover in horse herb.

Appreciate these tips. I also saw something about applying corn gluten meal in December, to decrease cg in Spring ...

CGM in December will do nothing but fertilize. Even as a fertilizer it will not do much until the sun warms the soil.

Timing for CGM in the spring is said to be when the forsythia are in full bloom in your neighborhood. That may well be, but we don't have forsythia in San Antonio. What we had this year was 17 inches of rain in January and Feb. THAT sprouted our weeds this year. After the drought for 2 years we had and have weeds everywhere.