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Native Plant Society of Texas

Sawtooth Sunflower

Helianthus grosseserratus

Other common name(s):

Family:

Asteraceae (Aster Family)

Plant Ecoregion Distribution Map

This map uses data from the US EPA. EPA  servers have been offline frequently so maps may not display. We are working on a solution.

East Central Texas Plains, Western Gulf Coastal Plain
Bastrop Lost Pines, Floodplains and Low Terraces2, Northern Post Oak Savanna, Northern Prairie Outliers, San Antonio Prairie, Southern Post Oak Savanna
Flatwoods, Southern Tertiary Uplands

Plant Characteristics

Growth Form

Herbaceous

Height

3
to
15
ft.

Spread

to
ft.

Leaf Retention

Deciduous

Lifespan

Perennial

Habitat and Care Requirements

Soil Type(s)

Sand, Caliche, Well Drained, Moist, Dry

Light Requirement

Sun

Water Requirement

Medium

Native Habitat

Grassland, Woodland, Wetland or Riparian

Bloom and Attraction

Bloom Color

Yellow

Bloom Season

Summer, Fall

Seasonal Interest

Seeds, Nectar, Pollen, Larval Host

Wildlife Benefit

Butterflies, Birds, Small Mammals, Moths, Bees

Maintenance

In continuous rain or grown in a long time in partial shade, may grow poorly and become weak Tolerates wide temperature range. Prune in early to late spring, thin for airflow and sunlight. Deadhead to promote more flowering or leave seeds for wildlife. Will spread prolificially so give lots of space or thin according to garden space. Native habitat: dry to wet prairies, bottom lands, streams and in low woods.

Comments

Blooms August – November. Reddish-purple stems erect, with coarsely serrated leaves, and pubescent underside. Small flower heads grow at the end of branched stems. ray flowers surrounding disc blowers. Larval host: Checkerspot.
Previous Scientific Name(s): Helianthus grosseserratus ssp. maximus, Helianthus grosseserratus var. hypoleucus, Helianthus instabilis

References

Learn about how to propagate Texas native plants.

Material Treatment Method Collection References
Seed Stratification Direct sow in late fall, planting the seeds 1/2" deep. For spring planting, mix the seed with moist sand and store it in the refrigerator for 30 days before direct sowing. To start indoors, sow seeds in a flat or individual peat pots, keeping the soil lightly moist and at a temperature of 65-70 degrees F until germination, which usually occurs within 10-20 days. Keep the seedlings moist. When the weather has warmed and the seedlings are well established, transplant outdoors. After their petals drop off, the centers of the flowers will darken and develop tight clusters of seed. Harvest the seed as soon as it ripens, since small birds love to eat it. Cut the heads and spread them out to dry for several days. Thresh the dried heads to separate the seed from the chaff. Store the cleaned seed in a cool, dry place. https://www.everwilde.com/store/Helianthus-grosseserratus-WildFlower-Seed.html
Seed Stratification The following steps for planting Sawtooth Sunflower seeds assume you are either Winter Sowing the seed, or have already cold-moist stratified (follow directions using the link provided in the References field. , Fill a suitable container with moist potting soil. Leave a 1/2″-3/4″ gap (6-9mm) from the top of the container. The potting soil should be wet enough that when you squeeze a handful only a few drops of water fall out. Gently tamp the soil firm Place 3-5 seeds on the soil surface. Press them so they have good contact. Cover seeds with 1/8″-1/4″ of moist potting soil. Place the container in a location that receives morning sun and afternoon shade. Keep the soil moist, watering as needed. Once germination occurs, grow the seedlings until they have 2-3 sets of true leaves. A couple other notes on caring for young seedlings. First, keeping the container in morning sun/afternoon shade is really beneficial. It allows the seedling sunlight for photosynthesis, but protects it from the hot afternoon sun, which can easily dry out small containers. https://growitbuildit.com/seed-stratification-illustrated-guide/

About the Region

Fall Symposium 2025 Logo - Teach for the Future

Salado, the location of our Fall 2025 Symposium, lies at the intersection of two ecoregions: the Edwards Plateau (Limestone Cut Plain) and Blackland Prairie (Northern Blackland Prairie).

The Edwards Plateau area is also called the Hill Country; however, this general term covers a much larger area extending farther north. Spring-fed creeks are found throughout the region; deep limestone canyons, rivers, and lakes (reservoirs) are common. Ashe juniper is perhaps the most common woody species found throughout the region. Additional woody species include various species of oak, with live oak (Quercus fusiformis) being the most common. Sycamores (Platanus occidentalis) and bald cypress (Taxodium distichum) border waterways. This area is well known for its spring wildflower displays, though they may be viewed in spring, late summer, and fall, as well. According to Texas Parks and Wildlife, average annual rainfall in the Edwards Plateau ranges from 15 to 34 inches.

The Blackland Prairie extends from the Red River south to San Antonio, bordered on the west by the Edwards Plateau and the Cross Timbers, and on the east by the Post Oak Savannah. Annual rainfall averages 30 to 40 inches, with higher averages to the east. This region is dominated by prairie species. The most common grass species include little bluestem (Schizachyrium scoparium) and Indian grass (Sorghastrum nutans) in the uplands and switchgrass (Panicum virgatum) in the riparian areas and drainages. Common herbaceous flowering plants include salvias, penstemons, and silphiums. This area has suffered greatly from overgrazing and agricultural use. Few intact areas remain, though many of the plants can be found along county roadsides throughout the region.

Our fall Symposium host chapter, the Tonkawa Chapter, includes both of these ecoregions.

Source: Wildflowers of Texas by Michael Eason