North America Non-native Plant

Spreading Amaranth

Botanical name: Amaranthus crassipes

USDA symbol: AMCR

Life cycle: annual

Habit: forb

Native status: It's either native or not native in the lower 48 states âš˜ Non-native, reproduces and persists in the wild in Puerto Rico âš˜ Non-native, reproduces and persists in the wild in the U.S. Virgin Islands  

Spreading Amaranth: A Weedy Wanderer You Probably Don’t Want in Your Garden If you’ve stumbled across the name spreading amaranth while researching plants for your garden, you might be wondering if this member of the amaranth family deserves a spot in your landscape. While Amaranthus crassipes has found its way ...

Spreading Amaranth: A Weedy Wanderer You Probably Don’t Want in Your Garden

If you’ve stumbled across the name spreading amaranth while researching plants for your garden, you might be wondering if this member of the amaranth family deserves a spot in your landscape. While Amaranthus crassipes has found its way into gardens across several U.S. states, it’s not exactly what most gardeners would call a desirable addition to their plant palette.

What is Spreading Amaranth?

Spreading amaranth is an annual forb—basically a non-woody flowering plant that completes its entire life cycle in one growing season. As a member of the amaranth family, it lacks the showy flowers or ornamental appeal that make its cultivated cousins popular in gardens. Instead, this plant tends to be more of an opportunistic colonizer than a garden showstopper.

Where Does It Grow?

Originally from tropical and subtropical regions of the Americas, spreading amaranth has established itself across a surprising range of U.S. states. You’ll find it growing in Alabama, Arizona, Florida, New Mexico, Pennsylvania, South Carolina, and Texas, as well as in Puerto Rico and the U.S. Virgin Islands. This wide distribution speaks to the plant’s adaptability, though not necessarily to its desirability.

Native Status: The Wandering Amaranth

Here’s where things get interesting—spreading amaranth isn’t native to the lower 48 states, yet it’s managed to establish reproducing populations in several regions. In Puerto Rico and the U.S. Virgin Islands, it’s considered a non-native species that reproduces spontaneously and persists without human help. This ability to naturalize wherever it lands is both impressive and concerning from a gardening perspective.

Should You Plant It?

The short answer? Probably not. While spreading amaranth isn’t listed as invasive or noxious, it’s not exactly garden material either. Here’s why most gardeners give this one a pass:

  • Limited ornamental value—the flowers are small and inconspicuous
  • Weedy growth habit that can spread beyond where you want it
  • No significant benefits to pollinators or wildlife
  • Tends to pop up on its own whether you want it or not

Growing Conditions and Adaptability

If spreading amaranth does show up in your garden (and it might, whether you plant it or not), you’ll find it’s remarkably adaptable. The plant can handle both wetland and upland conditions across most regions, though it shows a preference for non-wetland areas in the Caribbean. This flexibility in moisture requirements means it can establish itself in various garden situations.

As an annual, it thrives in warmer USDA hardiness zones, roughly 8-11, based on its current distribution. It’s drought-tolerant once established and isn’t particularly picky about soil conditions.

Better Native Alternatives

Instead of planting spreading amaranth, consider these native alternatives that offer similar adaptability with much greater garden value:

  • Native amaranths like Palmer amaranth or smooth pigweed (where native)
  • Native wildflowers suited to your specific region
  • Native grasses that provide wildlife habitat and erosion control
  • Regional native forbs that support local pollinator populations

The Bottom Line

Spreading amaranth is one of those plants that’s more likely to find you than the other way around. While it’s not harmful enough to warrant active removal efforts, it’s also not beneficial enough to earn a spot in most thoughtfully designed gardens. If you’re looking to support local ecosystems and create a beautiful landscape, you’ll find much better options among plants native to your specific region.

Remember, the best garden plants are those that provide multiple benefits—beauty, wildlife support, and ecological value. Spreading amaranth, while perfectly harmless, simply doesn’t check enough of these boxes to make it worth your gardening efforts.

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

Arid West

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Atlantic and Gulf Coastal Plain

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Caribbean

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Eastern Mountains and Piedmont

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Great Plains

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Northcentral & Northeast

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Western Mountains, Valleys, and Coast

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Spreading 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 crassipes Schltdl. - spreading amaranth

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