How much sun does Alligator-weed need?

Alligator-weed grows best in full sun conditions.

When does Alligator-weed bloom?

Alligator-weed blooms in June, July, and August.

Where is Alligator-weed native?

Alligator-weed (Alternanthera philoxeroides) is native to AR, per the USDA PLANTS Database and regional native plant society lists.

Is Alligator-weed toxic to livestock?

The USDA PLANTS Database does not flag Alligator-weed as toxic to livestock.

Is Alligator-weed HOA-friendly?

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

Alligator-weed

Name: Pollinator Patch
Author: Pollinator Patch

Alternanthera philoxeroides

Last reviewed: June 2026

The USDA PLANTS Database (opens in new tab) does not flag Alligator-weed as toxic to livestock.

Light

full sun

Water

high

Size

12"–36" H × 24"–120" W

Bloom

Jun, Jul, Aug

Native to

Browse plants for this ecoregion

Edwards Plateau Texas Blackland Prairies East Central Texas Plains Western Gulf Coastal Plain South Central Plains

Alligator-weed is an aggressive aquatic and semi-aquatic vine that spreads rapidly through waterways and wet areas. This invasive species forms dense mats that can quickly overtake native vegetation and is extremely difficult to control once established.

In an HOA neighborhood

Alligator-weed 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.

Classified as invasive species
Spreads aggressively and uncontrollably
May violate local noxious weed ordinances

Wildlife value

While it may provide some habitat for aquatic insects, this invasive plant displaces native species that offer much better wildlife value. Its aggressive nature actually reduces overall biodiversity in affected areas.

Common questions

How much sun does Alligator-weed need?: Alligator-weed grows best in full sun conditions.
When does Alligator-weed bloom?: Alligator-weed blooms in June, July, and August.
Where is Alligator-weed native?: Alligator-weed (Alternanthera philoxeroides) is native to AR, per the USDA PLANTS Database and regional native plant society lists.
Is Alligator-weed toxic to livestock?: The USDA PLANTS Database does not flag Alligator-weed as toxic to livestock.
Is Alligator-weed HOA-friendly?: Alligator-weed takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

Ready to grow Alligator-weed? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.

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