Arrowroot
Thalia geniculata
Last reviewed: June 2026
Light
part sun
Water
high
Size
36"–96" H × 24"–48" W
Bloom
Jun, Jul, Aug, Sep, Oct
Native to
FL, LA
Pollinators
bees, butterflies
Thalia geniculata is a tall, striking aquatic perennial with large arrow-shaped leaves and purple flower spikes that bloom from summer through fall. This moisture-loving plant grows 3-8 feet tall and thrives in wet soils, making it ideal for rain gardens or pond edges. Its bold architectural form adds tropical flair to water features and boggy areas.
In an HOA neighborhood
Arrowroot takes more care to keep looking intentional in a front yard. Maintenance level: moderate. Consider it for backyard or mid-zone beds rather than the street edge.
Works well in: backyard only.
- Very tall growth may appear overgrown
- Requires consistently wet conditions
- Tropical appearance may seem too informal for front yards
Wildlife value
The long-blooming purple flowers attract bees and butterflies throughout the growing season. The dense growth provides shelter for wildlife in wetland garden settings.
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.
Does Arrowroot fit your yard? Open it in Pollinator Patch to check it against your sun, soil, and HOA-conscious filters.