Skip to main content

Center for Aquatic and Invasive Plants Logo    Plant Management in Florida Waters

Center for Aquatic and Invasive Plants Logo    Plant Management in Florida Waters

Quick Facts

  • Scientific name: Hydrilla verticillata
  • Origin: Southeast Asia
  • Introduction: Early 1950s, aquarium trade
  • Aquatic community: Submersed, surface mats
  • Habitat: Inches to >30 feet deep
  • Distribution: Statewide
  • Management effort: Eradicate new infestations Maintenance control of established plants
  • 2020 Acres Treated: 16,100


Environmental and Economic Concerns

  • Stems can elongate as much as 6-8 inches per day in Florida’s peak growing season
  • Can cover entire water body surface 1-2 years after introduction
  • 80% of plant mass is in the upper two feet of water column
    • blocks sunlight and shades out native plants
    • blocks air exchange and consumes oxygen, leading to fish kills
    • blocks access, navigation, and recreation
    • breaks loose and jams against bridges and dams
  • Reduces recreation-based incomes and property values
  • Doubles sedimentation rate from senescing leaves and stems
  • Disperses by fragments, buds, and runners (does not produce seeds)
  • Resists long-term control via underground propagules (tubers)
    • millions produced per acre
    • no effective tuber control method
    • viable tubers lie dormant for as long as seven years

Management Options

  • Biological: Sterile grass carp stocked in about 100 public lakes; 4 host-specific insect species released with few successes; FWC is not currently funding overseas exploration for additional host-specific insects
  • Chemical: Large-scale: potassium endothall, diquat, bispyribac, fluridone, penoxsulam; topramezone – small-scale: copper, diquat – research is focusing on combinations of herbicides, especially contact type herbicides with systemics
  • Mechanical: Harvest from spring runs and boat trails in deep water, harvest or shred mats lodged against structures (bridges, dams)
  • Physical: Hand pull / diver dredge new infestations, or in fast-flowing water