Helianthus angustifolius
COMMON NAMES
Swamp Daisy, Swamp Sunflower, Narrowleaf Sunflower
Helianthus (hee-lee-AN-thus) – from the Greek for sun and flower
angustifolius (an-gus-tih-FO-lee-us) – having narrow leaves
GROUP
Dicot
FAMILY
Some taxonomists put in Asteraceae and others put in Compositae.
ORIGIN
Eastern United States
DESCRIPTION
Swamp Daisy is an evergreen herbaceous perennial that averages 4 to 6 feet in height with a comparable spread. It forms clumps with spreading rhizomes. It has a moderate to fast growth rate.
Leaves are evergreen, narrow, lanceolate, alternate in arrangement, simple, 3 to 6 inches long and ½ inch wide with dentate margins, rough textured, and dark green in color. It has pinnate veins, maroon stems, and coarse hairs on the lower stems.
The yellow daisy-like flowers are about 2 to 3 inches across with yellow rays and reddish brown to purple discs. It blooms from late summer to fall.
Fruit are brown and dry with seeds.
HARDINESS
It is hardy in USDA Zones 6 to 9. Freezes will kill to the ground to frequently resprout in the spring in warmer areas.
LIGHT
Full sun/part shade; it will be more dense and have more flowers in full sun.
SALT
Good Salt Spray Tolerance – it will grow near the shore but will benefit from a little protection such as behind the first row of plantings or behind the first dunes.
SOIL
It will grow on a wide variety of soils in the pH range of 5.5 to 7.5, even tolerating swamps and wetlands.
WATERING
It has moderate drought tolerance once established, but will tend to look a little better with irrigation in dry spells.
PROPAGATION
Seeds; division of rhizomes and plantlets
PRUNING
Pinch early on to promote branching, especially if growing in partial shade.
FERTILIZING
It has no special fertilizer needs. Unless a soil test suggests otherwise, a slow-release balanced analysis fertilizer applied per the product label will work.
PESTS
Fall Webworm, Saddleback Caterpillar
DISEASES
Powdery Mildew, Pythium Root Rot, Anthracnose, Botrytis, White Smut
DEER
Resistant
There are very few totally “deer-proof” plants. There are also, relatively speaking, few plants that are considered a preferred food supply of deer. Most plants fall in the big gap between. One of the biggest variables is the available preferred food supply in a given area. If their preferred food is scarce, they will munch on most anything.
OTHER
Good butterfly plant
USES
Specimen plant; butterfly garden; tall border/background; mass planting; wet areas
TOXICITY
A search of California Poison Control, Texas A&M University, Canadian Poisonous Plants Information System, University of Wisconsin, Poisonous Houseplants and Ornamentals - Merck Vet Manual, Purdue University - Guide to Toxic Plants in Forages, Poisonous Plants of the Southeastern United States - Alabama Cooperative Extension, Florida Poison Control, University of California, North Carolina State University, and The Cat Fanciers Association did not show this plant on any of their lists.
ASPCA lists Helianthus angustifolius as non-toxic to dogs, cats, and horses.
Copyright 2014 Looking at Plants. All rights reserved.