Helianthus angustifolius: Swamp Sunflower
Latin name: Helianthus angustifolius
Common name: Swamp Sunflower
Flowers: 2-3” yellow daisy-like flowers that bloom late summer – fall13,4
Fruit: Small achene in the fall13
Height & Width: 5-8’ x 2-4’13
Type: Herbaceous perennial10
Wetland indicator category**: FACW, FAC17
Growth rate: Medium13
Light: Full sun to part shade10,13
Soil*: Wet acidic sandy – clay loam13
Ecosystem benefits: It attracts and feeds birds and many insects including native bees10
Features: This plant produce many bright yellow flowers in the late summer that persist into the fall when other plants may not be blooming13. It also attracts several species of bird and insect10. It can be planted along streams or ponds and does well in pollinator or naturalized gardens13.
Siting: Swamp sunflower should be planted in moist to wet soil in full sun to part shade10. Since it can get up to 8 feet tall, it should be planted in the back of a garden with room to grow13.
Care: Plant crown at soil level18. At planting, water the roots and surrounding area slowly and deeply. Keep soil moist until plant is established, then apply enough water to thoroughly moisten the root zone when the soil is dry or during drought. Modify water recommendations to reflect site drainage and rainfall. Apply 3” of mulch over the planted area. Do not allow mulch to touch the plant stems18.
Pests: Plants are relatively pest resistant if cultural preferences are met.
Author: Kerrie McCaffrey
Image source: http://southeastgarden.com/helianthus.html
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- Armitage, A. (2008). Herbaceous perennial plants: A treatise on their identification, culture, and garden attributes. Athens, GA: University of Georgia.
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- USDA . Plant profile. (n/d).Retrieved from http://plants.usda.gov/java/
- USDA. Plant wetland indicator status. (n/d). Retrieved from http://plants.usda.gov/wetland.html
- Vincent, E., Environmental horticulturist Clemson University, personal communication.
- Clemson Extension. Carolina Yards Plant Database. Retrieved from https://www.clemson.edu/extension/carolinayards/plant-database/index.htm
*Soil pH is determined using a professional soil test. Contact your Clemson University County Extension service for assistance www.clemson.edu/extension/. Click on “local offices”.
**2012 Plant Wetland Indicator categories (quantitative derived) http://plants.usda.gov/wetinfo.html
|Indicator Code||Indicator Status||Comment|
|OBL||Obligate Wetland||Almost always is a hydrophyte, rarely in uplands|
|FACW||Facultative Wetland||Usually is a hydrophyte but occasionally found in uplands|
|FAC||Facultative||Commonly occurs as either a hydrophyte or non-hydrophyte|
|FACU||Facultative Upland||Occasionally is a hydrophyte but usually occurs in uplands|
|UPL||Obligate Upland||Rarely is a hydrophyte, almost always in uplands|