1. I live in Houston Texas and most of the grass out here is St. Augustine. I've tried various commercial week killers on my lawn but nothing seems to work well. Does anybody have any suggestions? I'm starting to think that these weed killers are just a rip-off.

2. I'm preping the soil to plant some rose bushes. Can someone recommend a good weed killer to use around the rose bushes to keep weeds from growing in this area?