Pendimethalin is sold commercially as Pendulum as well as several other names. On the homeowner side, it is sold as Scotts Halts. Pendimethalin is best applied as a split application with the first half applied about April 15 and the second about June 1. Alternatively, make the first application when redbud trees approach full bloom and the second six weeks later.
The “weed preventers” will not give complete control but should help. Quinclorac (Drive) can provide some postemergence control especially if the sandbur is in the seedling stage. Quinclorac is also found in a number of combination products that control both broadleaf weeds and crabgrass such as one of the following.
Ortho Weed-B-Gon Max + Crabgrass Control
BioAdvanced All-in-One Lawn Weed and Crabgrass Killer.
Monterey Crab-E-Rad Plus
Fertilome Weed Out with Crabgrass Killer
Trimec Crabgrass Plus Lawn Weed Killer
Bonide Weed Beater Plus Crabgrass & Broadleaf Weed Killer
Spectracide Weed Stop for Lawns Plus Crabgrass Killer
Again, the best control for grassy sandbur is a healthy, thick lawn. (Ward Upham)