Sium suave, with its tall stature and delicate umbels of white flowers, is a valuable plant for wetland areas. Ideal for rain gardens and water gardens, this native species supports pollinators and adds a natural beauty to wet landscapes. Its ability to thrive in consistently wet conditions makes it an essential addition to any water-adjacent garden space.​
 
General Information
Status in Florida: Native
Native Habitat: Wetlands, including wet prairies, seeps, swamps, marshes, and shallow water areas
Native States: Found throughout the United States, Canada, Japan, Russia, South Korea, and China
Growing Zones: Suitable for USDA Hardiness Zones 3 to 8
Size at Maturity: Can reach heights of up to 3 meters (approximately 10 feet) with stems up to 5 cm (2 inches) in diameter
Phenology: Perennial
Life Cycle: Perennial
Growth Rate: Moderate to fast
Growth Habit: Upright, with stems that may branch near the top
Bloom Season: July to August
Bloom Color: White
 
Growth Conditions
Sunlight Requirements: Full sun to partial shade
Soil Texture: Prefers wet, mucky soils or shallow water up to 1.5 inches deep
Soil pH: Tolerant of various pH levels but typically found in neutral to slightly acidic soils
Moisture Requirements: Requires consistently moist conditions; can grow in standing water
Tolerance to Salt Spray: Low tolerance; not recommended for coastal areas
Keystone Plant: No
 
Landscape Considerations
Recommended Landscape Uses: Ideal for wetland gardens, rain gardens, pond edges, and naturalized areas
Maintenance Tips: Minimal maintenance required; remove dead stems after flowering to maintain appearance
Considerations: Ensure the planting site has sufficient moisture; avoid planting near edible gardens due to potential confusion with toxic species
Hurricane Wind Resistant: Yes, due to its robust stem structure
Erosion Control: Effective in stabilizing soil in wet areas
Nitrogen Fixing: No
 
Other Information
Edible: The root is edible and has a nutty flavor; consume with caution and proper identification
Pet Safe: Yes
Deer and Rabbit Resistance: Yes
Historical Medicinal Uses: Traditionally used as a pain reliever for broken bones; consult a professional before use
Florida Native Companion Plant: Cicuta maculata (Spotted Water Hemlock)
Wildlife Benefit: Attracts various pollinators, including bees and butterflies
Caterpillar Host Plant: Yes, for certain butterfly species. As a member of the carrot family, this plant hosts the Black Swallowtail butterflies.
Propagation: Can be propagated by seed or division; seeds require cold stratification
 
Caution: Sium suave closely resembles the highly toxic Cicuta maculata (Spotted Water Hemlock). Proper identification is crucial before any interaction with the plant. The root is edible with a nutty flavor, but consumption should be approached with caution due to the risk of misidentification