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
Helianthus grosseserratus subsp. maximus
Helianthus instabilis
Sun Exposure
Full Sun
Foliage
Herbaceous
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)
Danger
N/A
Bloom Color
Bright Yellow
Bloom Time
Late Summer/Early Fall
Mid Fall
Other Details
Category
Perennials
Water Requirements
Average Water Needs; Water regularly; do not overwater
Foliage Color
Where to Grow
Bloom Characteristics
This plant is attractive to bees, butterflies and/or birds
Bloom Size
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
Regional

This plant is said to grow outdoors in the following regions:

Hinsdale, Illinois

Featured Videos

Gardener's Notes:

0
positive
1
neutral
0
negative
Sort By:
Sort By:
J
J
Palmyra, IL (Zone 5b) | January 2005 | neutral

The most common visitors to the flowers are bees, especially long-tongued species. Among these are honeybees, bumblebees, Epeoline Cuckoo...Read More

Featured
Green Cutworm Moth
(Anicla infecta)
Great Horned Owl
(Bubo virginianus)
Featured
Green Cutworm Moth
(Anicla infecta)
Great Horned Owl
(Bubo virginianus)