Naiad

One of the most common native, submerged pond plants in Pennsylvania.
Naiad - Articles

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Description

  • Fine stems with many branches.
  • Bundles of thin leaves along the stem.
  • On close examination, each fine leaf has very small teeth along the edge.
  • Depending on growing conditions, the plant can grow short and thick or tall and slender.
  • Naiad dies back each year and sprouts from seeds the following year.
  • It fragments very easily when pulled and can spread during the growing season by fragments.

Value and Concern to the Pond

  • Naiad is an important food source for all waterfowl.
  • Provides excellent underwater habitat for fish and invertebrates.
  • Modest growth of naiad is generally desirable for the pond ecosystem.
  • Excessive growth can occur under ideal conditions, leading to reduced recreational uses of the pond, the danger of reduced dissolved oxygen levels, and fish kills when it dies in the fall.

Prevention

  • Overabundant growth of naiad is a symptom of excessive nutrients (phosphorus and nitrogen) in the pond water from barnyards, crop fields, septic systems, lawns, and golf courses.
  • Control of overabundant aquatic plants is best accomplished by reducing or redirecting nutrient sources from the pond. This can be accomplished by reducing fertilizer applications near the pond, maintaining septic systems properly, redirecting nutrient rich runoff away from the pond, and maintaining vegetative buffer strips around your pond.
  • If you fail to address the underlying nutrient causes of aquatic plant growth you will probably encounter a perpetual need to control overabundant plant growth.

Physical Controls

  • Harvesting of naiad through cutting or raking is risky because of its ability to reproduce from the many fragments left behind after harvesting.
  • Drawdown can be somewhat effective, but the seeds are somewhat cold tolerant.

Biological Controls

  • Grass carp are an excellent control strategy for naiad since it is one of their favored foods.
  • Grass carp must be purchased from an approved hatchery after receiving a state permit.
  • For more information on the grass carp permit and approved hatcheries, consult the grass carp fact sheet available from your local Pa. Fish and Boat Commission office or online at the Penn State Extension website.

Chemical Controls

There are numerous aquatic herbicides that can be used to control naiad. You can learn more about these herbicide options in Management of Aquatic Plants . Here are some tips for properly using an aquatic herbicide to control naiad:

  • Keep in mind that chemical control is often necessary every year or even multiple times during a year.
  • Positively identify the plant in your pond as naiad before proceeding with chemical control.
  • Carefully measure the pond area and/or volume to determine the amount of herbicide needed. Consult the fact sheet titled Pond Facts 4: Measuring Pond Area and Volume  for more information.
  • Make sure that you obtain and submit the required state permit before applying the herbicide. Before applying a herbicide to your pond, you must obtain a state permit from the Pennsylvania Department of Environmental Protection. The two-page application form and instructions for this permit are online at Application for Use of an Algaecide, Herbicide, or Fish Control Chemical in Waters of the Commonwealth.
  • Aquatic herbicides can be purchased from some home and farm supply stores, hardware stores, or various online suppliers. Costs can range from less than $100 to more than $1,000 to treat a one-acre pond.
  • Follow the herbicide label carefully for specific instructions on when and how to apply the chemical.
  • Herbicide treatments should be done early in the growing season before the plants cover a large portion of the pond. Treatment of severe infestations may cause a fish kill due to reduced dissolved oxygen.

Prepared by Bryan R. Swistock, senior extension associate and Heather Smiles, fisheries biologist, Pennsylvania Fish and Boat Commission.

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