What kind of water does longleaf pondweed need?

Longleaf pondweed is a true aquatic plant and grows rooted in the mud of ponds, lakes, and slow moving streams where it stays submersed or floats its leaves at the surface. It does not tolerate drying out and needs consistently high water levels.

When does Potamogeton nodosus bloom?

It blooms from June through September, producing short spikes of small greenish flowers that emerge just above the water surface.

How much light does longleaf pondweed prefer?

It grows best in full sun to part shade over open water, and can persist in partly shaded coves or inlets where some canopy cover reduces direct light.

Is longleaf pondweed useful for wildlife habitat?

The submerged leaves and stems provide cover for fish and aquatic invertebrates, and the plant forms dense beds that help stabilize sediment in slow moving water bodies.

What does longleaf pondweed look like when it is not flowering?

Underwater it produces long, narrow submersed leaves, while floating leaves near the surface are broader and more oval, giving the plant its common name.

Is Longleaf Pondweed toxic to livestock?

The USDA PLANTS Database does not flag Longleaf Pondweed as toxic to livestock.

Is Longleaf Pondweed HOA-friendly?

Longleaf Pondweed takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Longleaf Pondweed

Name: Pollinator Patch
Author: Pollinator Patch

Potamogeton nodosus

Last reviewed: August 2026

Potamogeton nodosus, or longleaf pondweed, is a submersed aquatic forb found in ponds, slow rivers, and shallow lake margins. It blooms from June through September with small greenish flower spikes held above the water surface.

Toxicity unknown

Longleaf Pondweed (Potamogeton nodosus) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

The USDA PLANTS Database (opens in new tab) does not flag Longleaf Pondweed as toxic to livestock.

Light

part shade

Water

high

Size

12"–60" H × 12"–36" W

Bloom

Jun, Jul, Aug, Sep

Native to

AR, AZ, CA, CO and 43 more states

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Longleaf pondweed is an aquatic perennial that grows submerged or floating in ponds, lakes, and slow-moving streams. It produces long, narrow leaves and small flowering spikes that emerge above the water surface during summer months. This plant requires permanent water and is not suitable for typical garden beds.

Growing Longleaf Pondweed

Grow Longleaf Pondweed in part shade and high water. Mature plants reach 12 to 60 inches tall and spread 12 to 36 inches wide. Expect high maintenance to keep it looking intentional in a front yard.

In an HOA neighborhood

Longleaf Pondweed takes more care to keep looking intentional in a front yard. Maintenance level: high. Consider it for backyard or mid-zone beds rather than the street edge.

Requires permanent water feature
Not suitable for standard landscaping
May be considered pond maintenance issue

Wildlife value

Provides habitat and food for waterfowl, fish, and aquatic invertebrates. The seeds are eaten by ducks and other water birds.

Common questions

What kind of water does longleaf pondweed need?: Longleaf pondweed is a true aquatic plant and grows rooted in the mud of ponds, lakes, and slow moving streams where it stays submersed or floats its leaves at the surface. It does not tolerate drying out and needs consistently high water levels.
When does Potamogeton nodosus bloom?: It blooms from June through September, producing short spikes of small greenish flowers that emerge just above the water surface.
How much light does longleaf pondweed prefer?: It grows best in full sun to part shade over open water, and can persist in partly shaded coves or inlets where some canopy cover reduces direct light.
Is longleaf pondweed useful for wildlife habitat?: The submerged leaves and stems provide cover for fish and aquatic invertebrates, and the plant forms dense beds that help stabilize sediment in slow moving water bodies.
What does longleaf pondweed look like when it is not flowering?: Underwater it produces long, narrow submersed leaves, while floating leaves near the surface are broader and more oval, giving the plant its common name.
Is Longleaf Pondweed toxic to livestock?: The USDA PLANTS Database does not flag Longleaf Pondweed as toxic to livestock.
Is Longleaf Pondweed HOA-friendly?: Longleaf Pondweed takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.

Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

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