How to Grow Autumn Sun Sunflower
Autumn Sun Sunflower
Helianthus annuus 'Autumn Sun'
flowerAutumn Sun is a dwarf sunflower variety reaching 2-3 feet tall, producing abundant golden-yellow flowers with dark centers that bloom prolifically throughout late summer and fall. This cultivar is prized for its extended blooming season, compact growth habit, and excellent performance in cooler temperatures. It's ideal for borders, containers, and cut flower arrangements.
When should you plant Autumn Sun Sunflower in your zone?
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Example Autumn Sun Sunflower timeline · Pittsburgh, PA (Zone 6b)
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Plant Autumn Sun Sunflower
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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First Autumn Sun Sunflower blooms
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Autumn Sun Sunflower dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 2-9, with best performance in zones 4-8
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Seedling
2-3 weeksRapid germination within 7-10 days. Seedlings emerge with thick cotyledons and quickly develop true leaves.
Provide bright light and maintain consistent soil moisture. Thin seedlings to proper spacing early. Protect from strong winds.
Vegetative Growth
4-5 weeksPlant develops sturdy stems and increasingly complex foliage. Reaches 12-18 inches tall, establishing deep root system.
Support with stakes if in windy locations. Ensure consistent watering. Remove any competing weeds. Feed with balanced fertilizer every 3 weeks.
Budding
2-3 weeksTerminal flower buds form and begin to elongate. Plant reaches near-maximum height and lateral flower buds develop.
Continue regular watering and feeding with phosphorus-rich fertilizer to promote blooming. Monitor for pests and diseases.
Flowering
6-10 weeksLarge golden-yellow flowers open sequentially, with multiple side shoots blooming after terminal flower. Blooms often 4-6 inches across.
Maintain consistent moisture and continue light feeding. Deadhead spent flowers to encourage more blooms. This stage lasts through fall frosts in most zones.
Seed Development
3-4 weeksFlowers fade and seed heads mature, developing intricate seed patterns in brown and gold tones.
Stop deadheading if saving seeds. Allow seed heads to dry on plant. Cut when seeds are dry if harvesting for wildlife or replanting.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Remove infected seed heads, use spinosad spray, encourage natural predators like parasitic wasps
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Spray with strong water stream, apply insecticidal soap, introduce ladybugs, use neem oil
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Increase humidity, spray with water, apply neem oil or miticide if severe
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Improve air circulation, avoid overhead watering, apply fungicide if needed, remove infected leaves
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and
Hand-pick, use copper tape around containers, apply diatomaceous earth, encourage predators
Uses
Edible Seeds & Oil
CulinaryThe mature seeds are edible and can be roasted as a snack or pressed for sunflower oil rich in vitamin E and linoleic acid. Autumn Sun produces prolific seed heads ideal for seed harvesting. [source]
Fresh & Dried Cut Flowers
HouseholdExcellent as a cut flower arrangement, lasting up to two weeks in water when stems are cut at a 45-degree angle. Also dries well for permanent arrangements and decorative displays. [source]
Seed Source for Birds
WildlifeMature seed heads provide essential food for songbirds including goldfinches, chickadees, and nuthatches in fall and early winter. Leaving seed heads standing provides natural food during migration and winter months. [source]
Dried Arrangements & Crafts
CraftDried flower heads and stems are perfect for floral arrangements, wreaths, and dried flower crafts. Seeds can be used in mosaics and craft projects. [source]
Traditional Herbal Uses
MedicinalSunflower seeds are traditionally used in herbal medicine for cardiovascular health and contain selenium with antioxidant properties. Petals have been used in herbal infusions. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
For cut flowers: Cut stems early morning when flowers are fully open but pollen is still fresh. Cut at a 45-degree angle, strip lower leaves, and place immediately in water. Stems last 7-12 days indoors. For seeds: Allow flowers to fade completely and seed heads to dry on the plant. Cut when seed heads turn brown and seeds are fully mature (typically October-November). Hang bundles upside down in a cool, dry place to fully dry, then extract seeds.
Fun Facts
- 🌱 Autumn Sun's extended blooming season makes it unique among sunflower varieties—it continues flowering through light frosts and cooler fall temperatures when most other sunflowers have faded.
- 🌱 Sunflowers are heliotropic during their youth, with young buds following the sun's path from east to west during the day; mature Autumn Sun flowers remain facing east to warm up visiting pollinators.
- 🌱 Sunflowers are phytoremediation plants that can absorb toxins and heavy metals from soil, making them useful for ecological restoration projects.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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