North America Non-native Plant

Pondweed

Botanical name: Potamogeton tricarinatus

USDA symbol: POTR3

Life cycle: perennial

Habit: forb

Native status: Non-native, reproduces and persists in the wild in Hawaii  

Pondweed: A Water Garden Plant Worth Considering If you’ve been dreaming of adding some aquatic flair to your garden, you might have stumbled upon pondweed (Potamogeton tricarinatus). This underwater beauty has found its way into Hawaiian waters and the hearts of some water garden enthusiasts. But is it right for ...

Pondweed: A Water Garden Plant Worth Considering

If you’ve been dreaming of adding some aquatic flair to your garden, you might have stumbled upon pondweed (Potamogeton tricarinatus). This underwater beauty has found its way into Hawaiian waters and the hearts of some water garden enthusiasts. But is it right for your backyard pond? Let’s dive in and explore what makes this aquatic plant tick.

What Exactly Is Pondweed?

Pondweed is a perennial forb that’s perfectly at home underwater. Think of it as the aquatic equivalent of your favorite garden perennial – it comes back year after year, but instead of popping up from soil, it thrives completely submerged in water. This plant belongs to a large family of aquatic plants, and our particular species has narrow, linear leaves that grow in attractive whorls around the stem.

Where Does It Come From?

Here’s where things get interesting: this pondweed isn’t originally from Hawaii, where it currently grows. It’s actually a world traveler that originated in tropical and subtropical regions of Africa and Asia. Today, you’ll find it established in Hawaiian waters, where it’s made itself quite at home as a non-native species that reproduces on its own.

The Good, The Bad, and The Wet

Since this pondweed is non-native, you might wonder whether you should invite it into your water garden. The good news is that it’s not currently listed as invasive or noxious, which means it’s not causing major ecological havoc. However, as responsible gardeners, it’s always worth considering native alternatives first.

This plant is classified as an obligate wetland species, which is a fancy way of saying it absolutely must have water to survive. No weekend watering schedule here – this plant needs to be submerged almost all the time!

What’s It Like to Look At?

If you’re expecting showy flowers or dramatic foliage, pondweed might not be your star player. Its beauty is more subtle – think elegant underwater grass rather than flashy water lily. The narrow leaves create a gentle, swaying texture underwater that can add movement and interest to your aquatic landscape.

Perfect Spots for Pondweed

This aquatic plant shines in:

  • Water gardens and ornamental ponds
  • Aquatic features in larger landscapes
  • Bog gardens with consistently wet conditions
  • Natural swimming pools or pond ecosystems

Growing Conditions That Make It Happy

Pondweed is surprisingly straightforward to grow if you can meet its basic needs:

  • Water: Must be constantly submerged – this isn’t a plant that tolerates dry spells
  • Light: Full sun to partial shade works well
  • Temperature: Thrives in USDA hardiness zones 9-11, perfect for tropical and subtropical climates
  • Water quality: Prefers neutral to slightly alkaline water

Planting and Care Made Simple

Getting started with pondweed is refreshingly uncomplicated:

  • Plant in submerged containers or directly in pond substrate
  • Maintain consistent water levels – remember, this plant can’t handle being high and dry
  • Provide adequate water circulation for healthy growth
  • Be prepared to thin it occasionally if it gets too enthusiastic
  • No fertilizing needed – it gets nutrients directly from the water

Wildlife and Pollinator Benefits

While pondweed won’t attract butterflies to your garden like terrestrial flowers might, it does contribute to aquatic ecosystems by providing oxygen to the water and potentially offering habitat for aquatic wildlife.

Should You Grow It?

Pondweed can be a nice addition to water gardens, especially if you’re looking for subtle aquatic texture rather than showy blooms. Since it’s non-native but not problematic, the choice really comes down to your personal preferences and garden goals.

If you’re leaning toward native alternatives, consider researching indigenous Hawaiian aquatic plants that might offer similar benefits while supporting local ecosystems. Your local native plant society or extension office can be great resources for finding native aquatic options.

Whatever you choose, remember that water gardening opens up a whole new world of possibilities – and pondweed just might be your gateway into this fascinating aquatic realm!

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Hawaii

OBL

Obligate Wetland - Plants with this status almost always occurs in wetlands

Pondweed

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Alismatidae

Order

Najadales

Family

Potamogetonaceae Bercht. & J. Presl - Pondweed family

Genus

Potamogeton L. - pondweed

Species

Potamogeton tricarinatus F. Muell. & A. Benn. ex A. Benn. - pondweed

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA