Tropical Zone

Bahiagrass Lawn Calendar

Preemergence Weed Control

Preemergence herbicides must be applied prior to germination to be effective on targeted weed species. Sequential applications improve control over single applications and applications should be watered-in to maximize control and limit off-site movement.
Crabgrass, sandbur, prostrate knotweed, or spurge germinate in spring, so preemergence herbicide applications should be timed prior to 4” soil temperatures of approximately 55°F for five days. Spring applications of Specticle^® FLO or Echelon^® can prevent germination of summer grassy and broadleaf (BDLV) weeds.
Winter annuals like annual bluegrass, chickweed, and henbit germinate in the fall. Fall applications of Specticle FLO or Echelon can prevent germination of winter grassy and BDLV weeds with late summer/early fall applications at 4” soil temperatures at 70°F.

Summer and winter grassy and BDLV weeds are best controlled by postemergence herbicides when plants are small but actively growing. Be careful with products like metsulfuron that are mobile in the soil when applying around shallow rooted trees.
Summer annual grassy and BDLV weeds are best controlled in late spring/early summer with Celsius, Celsius^® XTRA, Blindside^®, Dismiss^® South, Xonerate^® or Solitare^®.
Winter annual grassy weeds and BDLV weeds are best controlled in fall or early spring with Celsius, Blindside, Dismiss South or Xonerate.
Sedges and kyllingas emerge primarily in spring. Dismiss Blindside, Celsius XTRA or Solitare are all effective, but herbicides for these sedges usually require multiple applications for most effective control.

White grubs are usually controlled with preventative applications made at the first sign of adult flight in the spring. New formulations like Durentis™ allow flexible timing of applications well before white grub adults appear and provides lasting control. Merit^® has been the industry standard for white grub preventative control. Though curative applications are usually inefficient, Dylox^® is the industry standard and provides quick knockdown of white grubs.
Applications of Durentis should be made in the spring (at first sign of adults) for season-long control of caterpillars including fall armyworms, cutworms, and sod webworms. Certain products can provide quick knockdown of caterpillars like Talstar^® (no residual) or Triple Crown^® (some residual control).
Monitor for chinch bugs throughout the summer with soap flushes or watch for insect damage that mimics drought stress. Applications of Triple Crown or Talstar can provide quick knockdown and residual control (Triple Crown) of chinch bugs throughout the summer.
Fire ant mounds can be unsightly, and their stinging makes them a human nuisance while mole crickets can cause significant damage to turf areas. TopChoice^® is the industry standard for season-long control of existing fire ant populations and mole crickets. Triple Crown or Talstar can provide quick knockdown of fire ant populations.

Large patch typically develops with high soil moisture and when 2” soil temperatures decline to below 70°F. Applications of preventative fungicides, like Armada^® or Fame^®, in the fall when conditions are conducive for disease development.

Mosquito control can be accomplished in early spring with larvicides (methoprene or pyriproxyfen) applied to standing water or adulticides (Scion^® or Talstar) applied as barrier treatments late spring through the fall.