Sawtooth Sunflower
Sawtooth Sunflower can be distinguished from other Sunflowers by its red, smooth stems. Sawtooth Sunflower thrives in both disturbed and high quality sites, sometimes forming large colonies that exclude other plants.
Botanical Name: Helianthus grosse-serratus
Nom Français: Tournesol en dents de scie

Features

Bloom colour: Yellow
Blooms: Fall - Zone 5
Pollinators: Bees | Birds | Bumble bees | Butterflies
Sun or Shade: Full Sun
Plant Type: Perennial
Height: Up to 9+ feet (3.5 meters)
Eastern North America
It grows well in hardiness zones: 3-8

Despite its name, the sawtooth sunflower doesn't normally have serrated leaves. They can be recognized by their smooth reddish stems and bright yellow blooms. They consist of 10-20 oval-shaped petals and an orange-yellow center. It blooms from August to October.

Planting

Meadow, full sun
Water requirement: Average water requirement. But, Keep soil moist throughout growth and bloom season.
Clay to Sandy Loam And Soil PH:Neutral to Slightly Acidic
If planting annual sunflower seeds, do so in springtime when the risk of frost has passed. When planting perennials, it can be done in fall or spring. Dig over the soil, then rake over and firm. Plant the seeds 1 inch deep and depending on the size of the plant, leave about 12 inches apart. Perennial flowers will spread by rhizomes, so consider leaving about 2 feet of space between seeds. Cover with soil and water lightly but thoroughly. A light spread of fertilizer will help the roots grow stronger and protect against wind damage.

Care

Low maintenance. It requires lots of room because of its large (sometimes huge) size and aggressive tendencies. This robust plant will tolerates many kinds of soil. Powdery mildew may affect the leaves, but this typically occurs during the fall after the blooming period. Strong wind can cause this plant to blow over in exposed situations.
Upright Clump, Slowly Spreading
Powdery mildew may occur as well as fungal leaf spots. Caterpillars, beetles and weevils may attack plants as well.

Pruning

Spread: Up to 1 meter
Divide sunflowers every 2-3 years. Sunflowers are very vigorous rooted, so should not require much aftercare.

Considerations

Honeybees, bumblebees and other bees are commonly attracted to this flower. It also attracts butterflies, moths, beatles and bee flies. Caterpillars of a variety of moths and butterflies also feed on the foliage, stems and seeds. Birds such as quail, partridge, balack birds, sparrows, goldfinch and mourning doves regularly and help spread the seeds.
Native to Canada

Styling and Use

Most sunflowers are rhizomatous and can also be aggressive and therefore may not be suitable for small landscape plantings. They thrive in full sun with acidic or neutral well-drained, moist soils. Wind may damage the heads, so it is best to plant them in a sheltered location. They grow naturally in prairies, banks of streams, margins of ponds and lakes, ditches, pastures and by railroads.
Heliopsis helianthoides 'Asahi' (False Sunflower), Amorpha canescens

Other

Sawtooth sunflowers make great freshly cut bouquets. Simply remove the leaves that fall below the water line.

History

Indigenous peoples used to treat burns with a poultice made from the flowers.

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