Helianthus Species, Sawtooth Sunflower, Thick-Tooth Sunflower
Helianthusgrosseserratus

Family: Asteraceae (ass-ter-AY-see-ee)
Genus: Helianthus (hee-lee-AN-thus)
Species: grosseserratus (gros-ser-AY-tus)

Synonym:Helianthus grosseserratus var. hypoleucus

Synonym:Helianthus grosseserratus subsp. maximus

Synonym:Helianthus instabilis

Category
Perennials

Water Requirements
Average Water Needs; Water regularly; do not overwater

Sun Exposure
Full Sun

Foliage
Herbaceous

Foliage Color

Height
36-48 in. (90-120 cm)
4-6 ft. (1.2-1.8 m)
6-8 ft. (1.8-2.4 m)
8-10 ft. (2.4-3 m)
10-12 ft. (3-3.6 m)

Spacing
9-12 in. (22-30 cm)
12-15 in. (30-38 cm)
15-18 in. (38-45 cm)
18-24 in. (45-60 cm)

Hardiness
USDA Zone 3a: to -39.9 °C (-40 °F)
USDA Zone 3b: to -37.2 °C (-35 °F)
USDA Zone 4a: to -34.4 °C (-30 °F)
USDA Zone 4b: to -31.6 °C (-25 °F)
USDA Zone 5a: to -28.8 °C (-20 °F)
USDA Zone 5b: to -26.1 °C (-15 °F)
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)
USDA Zone 10a: to -1.1 °C (30 °F)
USDA Zone 10b: to 1.7 °C (35 °F)
USDA Zone 11: above 4.5 °C (40 °F)

Where to Grow

Danger
N/A

Bloom Color
Bright Yellow

Bloom Characteristics
This plant is attractive to bees, butterflies and/or birds

Bloom Size

Bloom Time
Late Summer/Early Fall
Mid Fall

Other details

Soil pH requirements
6.6 to 7.5 (neutral)

Patent Information

Propagation Methods
By dividing rhizomes, tubers, corms or bulbs (including offsets)
From seed; direct sow outdoors in fall
From seed; winter sow in vented containers, coldframe or unheated greenhouse
From seed; stratify if sowing indoors

Seed Collecting
Allow seedheads to dry on plants; remove and collect seeds