North America Native Plant

Loose Watermilfoil

Botanical name: Myriophyllum laxum

USDA symbol: MYLA2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Loose Watermilfoil: A Rare Native Aquatic Gem for Your Water Garden If you’re looking to add authentic southeastern native flair to your water garden or pond, loose watermilfoil might just be the underwater treasure you’ve been seeking. This delicate aquatic perennial brings feathery texture and ecological value to wetland gardens, ...

Rare plant alert!

Region: Alabama

Status: S3: Status is uncertain but is somewhere between the following rankings: Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘ Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘

Region: Alabama

Loose Watermilfoil: A Rare Native Aquatic Gem for Your Water Garden

If you’re looking to add authentic southeastern native flair to your water garden or pond, loose watermilfoil might just be the underwater treasure you’ve been seeking. This delicate aquatic perennial brings feathery texture and ecological value to wetland gardens, though its rarity makes it a special find worth treating with extra care.

What Makes Loose Watermilfoil Special

Loose watermilfoil (Myriophyllum laxum) is a true southeastern native, naturally occurring in Alabama, Florida, Georgia, Mississippi, North Carolina, and South Carolina. As its name suggests, this aquatic forb has a more relaxed, open growth pattern compared to some of its watermilfoil cousins. The plant produces delicate, feathery underwater foliage that creates beautiful texture beneath the water’s surface, while small emergent flower spikes add subtle interest above water.

A Plant That Needs Our Protection

Here’s something important every responsible gardener should know: loose watermilfoil is considered vulnerable throughout its range, with a global conservation status of S3. In Alabama, it’s even more imperiled with an S2 status. What does this mean for you? If you choose to grow this native beauty, make absolutely sure you’re sourcing it responsibly from reputable native plant nurseries that propagate their own stock rather than wild-collecting.

Perfect for Wetland and Water Gardens

This obligate wetland plant is happiest with its feet completely wet. Whether you’re creating a naturalized pond edge, restoring a wetland area, or adding native character to a water garden, loose watermilfoil thrives in:

  • Shallow water areas (a few inches to a foot deep)
  • Saturated bog garden conditions
  • Full sun to partial shade locations
  • USDA hardiness zones 6-9

Growing and Caring for Loose Watermilfoil

The good news is that once established in the right conditions, loose watermilfoil is relatively low-maintenance. As a perennial forb, it lacks woody growth and instead produces soft, herbaceous stems that die back in winter and regrow each spring.

Key growing tips include:

  • Plant in consistently moist to waterlogged soil or shallow standing water
  • Provide at least 4-6 hours of direct sunlight daily
  • Consider containment in smaller water features to control spread
  • Allow natural winter dieback and spring regrowth

Wildlife Value and Ecological Benefits

While we don’t have extensive data on loose watermilfoil’s specific wildlife benefits, aquatic native plants like this one typically support aquatic insects, provide shelter for small fish and amphibians, and contribute to overall wetland ecosystem health. The emergent flowers may attract some pollinators, though this isn’t the plant’s primary ecological role.

Should You Plant Loose Watermilfoil?

If you have the right aquatic conditions and are committed to responsible sourcing, loose watermilfoil can be a wonderful addition to a native wetland garden. However, given its vulnerable status, consider these alternatives if you can’t find responsibly propagated stock:

  • Other native aquatic plants from your region
  • More common watermilfoil species (verify they’re native to your area)
  • Native sedges and rushes for wetland edges

Remember, every time we choose native plants—especially rare ones—we’re voting for biodiversity and supporting the intricate web of life that makes our local ecosystems thrive. Just make sure you’re doing it responsibly!

Loose Watermilfoil

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Haloragales

Family

Haloragaceae R. Br. - Water Milfoil family

Genus

Myriophyllum L. - watermilfoil

Species

Myriophyllum laxum Shuttlw. ex Chapm. - loose watermilfoil

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