re: Spring Weed Guide For Lawns

^Yep, Roundup is the only real post emergent option. Mix it strong, about 12 oz. per gallon, and wipe on using either a paint roller dipped in the solution, or a latex glove under a cotton glove dipped in it. Wiping/rolling on instead of spraying will keep you from having an collateral damage to the desirable flowers in the bed.

Usually it's Bermuda that intrudes flowerbeds and not torpedo, but either way the above method will work.

The granular you have sounds like a pre-emergent (Barricade, Freehand, etc.)