Hydrilla

Description

Hydrilla is a perennial plant that forms dense colonies and can grow to the surface in water over 20 feet deep. Hydrilla branches profusely and after reaching the surface it extends across it forming thick mats. Hydrilla can reproduce by fragmentation, from seeds, from turions (axillary buds), and from tubers. Leaves are blade-like about 1/8 inch and 3/8 inch long with small tooth margins and spines on the underside of the midrib that make them feel rough. Leaves are usually 4 to 8 in a whorl.


Other Names: Elodea

Mechanical Control

Hydrilla can be removed by cutting and raking from the pond. It will regrow from remaining roots and seeds.


Pond Dye can be used to limit sunlight into the pond. With reduced sunlight, photosynthesis cannot occur so growth will be stunted.

Chemical Control

There are several options to control Hydrilla:

  1. Use a season long herbicide such as Sonar A.S.. One treatment treats Hydrilla and many other common pond weeds for the season.
  2. Use a broad spectrum contact herbicide, such as Ultra PondWeed Defense®, will quickly kill Hydrilla. Because it does not stay in the water body, multiple treatments may be needed throughout the season.
  3. Use Clipper, a fast and selective herbicide that controls tough invasive and nuisance aquatic plants.

Chemical Application Best Practices

Anytime you use chemicals treat weeds and algae, please keep in mind the following:

  • Treat your pond in sections. Treat only half the pond's surface at a time, if the weather is hot, only treat 1/4-1/3 of your pond. Wait 10-14 days between treatments.
  • Once the weeds have browned & died, use a weed cutter & rake to remove as much dead material as possible. This prevents an accumulation of dead plant material and muck.
  • Take a proactive approach to pond management. Use PondClear, MuckAway and Pond Dye to keep your pond looking great. For more information, see our article on the Airmax® Ecosystem

Ask an Expert

If you are unable to identify your pond weed(s) using our Weed ID Guide, follow this article to email us a photo.

  • List | Grid

Products

  • Pond Logic® Ultra PondWeed Defense® Aquatic Herbicide

    Pond Logic® Ultra PondWeed Defense® Aquatic Herbicide

    Review star icon Review star icon Review star icon Review star icon Review star icon
    Broad Spectrum Pondweed Control Fast Acting Liquid Formula Short Term Control Of Duckweed Pond Logic ® Ultra Pondweed Defense ® works on pond weeds including submerged, floating and emergent weeds. It may be used for short term control of...
    Read More »
    $49.99–$149.99
  • Hydrothol® Granular Aquatic Algaecide & Herbicide

    Hydrothol® Granular Aquatic Algaecide & Herbicide

    Review star icon Review star icon Review star icon Review star icon Review star icon
    Fast-Acting Granular Formula Great For Bottom Growing Algae & Chara Control Weeds Surrounding Docks & Shorelines Hydrothol ® Granular algaecide and herbicide for ponds provides rapid-acting contact control for submerged weeds and algae....
    Read More »
    $119.99
  • Aquathol® Aquatic Herbicides

    Aquathol® Aquatic Herbicides

    Review star icon Review star icon Review star icon Review star icon Review star icon
    Eliminate Submerged Weeds Available in Liquid or Granular Formulas Great For Use In Turbid Ponds Aquathol ® aquatic herbicide effectively eliminates a wide variety of submerged weeds. As potency is unaffected by surrounding organics, Aquathol...
    Read More »
    $139.99–$329.99
  • SePRO Sonar™ A.S. Aquatic Herbicide

    SePRO Sonar A.S. Aquatic Herbicide

    Review star icon Review star icon Review star icon Review star icon Review star icon
    Season Long Weed Control Treats Floating & Submerged Weeds Systemic Herbicide That Kills Roots Even the most persistent weeds don't stand a chance against Sonar™. SePRO Sonar™ A.S. Aquatic Herbicide can be used to control stubborn...
    Read More »
    $239.99–$2,399.99
  • Valent® Clipper™ Aquatic Herbicide

    Valent® Clipper Aquatic Herbicide

    Review star icon Review star icon Review star icon Review star icon Review star icon
    Fast & Selective Control Of Weeds Treats Floating & Submerged Weeds Dissipates Quickly Through Water Column Valent ® Clipper ™ Aquatic Herbicide delivers fast and selective control of tough invasive and nuisance plants such as...
    Read More »
    $229.99–$899.99
  • SePRO Total Pond - Prevent®

    SePRO Total Pond - Prevent®

    Prevent & Control Weeds All Season Systemic Herbicide That Kills Roots Easy-To-Apply Granular Formulation SePro Total Pond - Prevent ® controls a wide variety of submerged and floating aquatic vegetation with a single treatment. Prevent...
    Read More »
    $84.99
    Qty.