North America Native Plant

Tidalmarsh Amaranth

Botanical name: Amaranthus cannabinus

USDA symbol: AMCA2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Acnida cannabina L. (ACCA11)   

Tidalmarsh Amaranth: A Specialized Native for Wetland Gardens If you’re looking to create an authentic wetland garden or restore a marshy area on your property, tidalmarsh amaranth (Amaranthus cannabinus) might just be the native plant you’ve been searching for. This lesser-known member of the amaranth family has carved out a ...

Tidalmarsh Amaranth: A Specialized Native for Wetland Gardens

If you’re looking to create an authentic wetland garden or restore a marshy area on your property, tidalmarsh amaranth (Amaranthus cannabinus) might just be the native plant you’ve been searching for. This lesser-known member of the amaranth family has carved out a very specific niche in nature – and it’s pretty particular about where it calls home!

What Makes Tidalmarsh Amaranth Special?

Tidalmarsh amaranth is a perennial forb that’s truly committed to the wetland lifestyle. Unlike its more famous amaranth cousins that you might find in vegetable gardens, this native species has evolved to thrive in consistently wet conditions. It’s what botanists call an obligate wetland plant, which is a fancy way of saying it almost always needs its feet wet to be happy.

This herbaceous plant lacks the woody stems you’d find on shrubs or trees, instead growing fresh green stems each season. As a native species to the lower 48 states, it has been quietly doing its job in coastal marshes and wetlands long before European settlers arrived.

Where You’ll Find It Growing Wild

Tidalmarsh amaranth has made itself at home along the eastern seaboard, from Maine down to Florida and stretching inland to include states like Alabama, Louisiana, and Pennsylvania. You’ll find it naturally occurring in 18 states total: Alabama, Connecticut, Delaware, District of Columbia, Florida, Georgia, Louisiana, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, and Virginia.

Is This Plant Right for Your Garden?

Here’s where we need to have an honest conversation. Tidalmarsh amaranth isn’t your typical garden center find, and there’s a good reason for that. This plant has very specific requirements that make it suitable only for certain types of landscapes:

  • Wetland gardens: Perfect for constructed wetlands or bog gardens
  • Rain gardens: Ideal for areas that collect and hold water
  • Restoration projects: Excellent for rehabilitating damaged wetland areas
  • Naturalized landscapes: Great for low-maintenance, native plant communities

If you have a typical suburban yard with well-drained soil, this probably isn’t the amaranth for you. But if you’re dealing with a persistently wet area that other plants struggle with, tidalmarsh amaranth could be your solution!

Growing Conditions and Care

Since tidalmarsh amaranth is classified as obligate wetland across all regions where it grows – from the Atlantic and Gulf Coastal Plain to the Eastern Mountains and Piedmont, and up to the Northcentral and Northeast regions – your growing conditions need to mimic its natural marsh habitat.

This means:

  • Consistently moist to saturated soil
  • Tolerance for periodic flooding
  • Full sun to partial shade conditions
  • Rich, organic soils typical of wetland areas

The Challenge of Finding and Growing It

Here’s the reality check: tidalmarsh amaranth can be tricky to source and grow. It’s not commonly available in nurseries, and its specialized habitat requirements mean it won’t thrive in conventional garden settings. If you’re interested in adding this native to your wetland restoration project, you’ll likely need to:

  • Contact specialized native plant nurseries
  • Work with wetland restoration professionals
  • Ensure you have the proper wet conditions year-round
  • Be patient with establishment, as wetland plants can take time to settle in

Wildlife and Ecological Benefits

While specific wildlife benefits for tidalmarsh amaranth aren’t well-documented, plants in the amaranth family typically provide value to wildlife through their seeds and habitat. As a native wetland plant, it likely plays important roles in:

  • Providing habitat for wetland-dependent wildlife
  • Supporting the complex wetland ecosystem food web
  • Helping with erosion control in wet areas
  • Contributing to water filtration and quality improvement

The Bottom Line

Tidalmarsh amaranth is a specialized native plant that serves an important ecological role in wetland habitats. While it’s not suitable for most home gardens, it can be an excellent choice for wetland restoration projects, constructed wetlands, or rain gardens where maintaining wet conditions year-round is feasible.

If you’re passionate about native plants and wetland conservation, and you have the right conditions, tidalmarsh amaranth could be a fascinating addition to your landscape. Just remember – this plant knows what it wants, and what it wants is wet feet and a marshy home!

For most gardeners looking to incorporate amaranth family plants, consider exploring other native options that are more adaptable to typical garden conditions, while reserving tidalmarsh amaranth for those special wetland projects where it can truly shine.

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

Atlantic and Gulf Coastal Plain

OBL

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

Eastern Mountains and Piedmont

OBL

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

Northcentral & Northeast

OBL

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

Tidalmarsh Amaranth

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Caryophyllidae

Order

Caryophyllales

Family

Amaranthaceae Martinov - Amaranth family

Genus

Amaranthus L. - pigweed

Species

Amaranthus cannabinus (L.) Sauer - tidalmarsh amaranth

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