SpeedZone Mixing Calculator: Oz Per Gallon

The fourth active is what makes it fast

2,4-D, MCPP, and dicamba are all growth-regulator herbicides — they work by overloading the plant's hormone system, which takes days to visibly show and one to two weeks to finish the job. SpeedZone adds a fourth active, carfentrazone-ethyl, a fast-acting contact herbicide that disrupts cell membranes in treated leaf tissue directly, causing visible browning within about 24 hours. The combination gets you both: quick visual confirmation the product is working, plus the slower systemic actives actually killing the root.

That speed comes with a real tradeoff: SpeedZone's label is more restrictive on turf type than a straight 2,4-D or Trimec product. The standard formula excludes several warm-season grasses outright rather than just reducing the rate — check the restrictions below before spraying an unfamiliar lawn.

Where SpeedZone can't go

• Not labeled for bahiagrass, buffalograss, carpetgrass, centipedegrass, dichondra, or St. Augustinegrass — not a reduced rate, a full exclusion. SpeedZone Southern is the separate formula built for those grass types; don't substitute the standard product.
• Skip lawns with desirable clover — SpeedZone kills it along with the target weeds.
• Timing: delay mowing 1–2 days before and after application; wait for the label's minimum interval between the two allowed broadcast applications per year.
• Tank-mixing: can be combined with a quinclorac product to broaden control, but quinclorac typically needs an MSO surfactant added — test a small area first, since the extra surfactant can increase sensitivity on desirable turf.