How to Grow Sunflower 'Astra Rose'

Closest match — some photos here may show the parent species rather than this specific variety.

Sunflower 'Astra Rose'

Helianthus annuus 'Astra Rose'

flower

Astra Rose is a stunning double-flowered sunflower variety featuring fully petaled, rose-like blooms in soft pink to mauve tones. Unlike traditional sunflowers with a dark central disc, these flowers have a completely filled, pompom-like appearance. This is an excellent cut flower variety that grows 24-30 inches tall and blooms prolifically throughout summer.

When should you plant Sunflower 'Astra Rose' in your zone?

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Example Sunflower 'Astra Rose' timeline · Pittsburgh, PA (Zone 6b)

Plant Sunflower 'Astra Rose'
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
First Sunflower 'Astra Rose' blooms
Around Jun 26

≈ 70 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Sunflower 'Astra Rose' dates for your own zip code.

Growing Conditions

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Sun: Full sun, 6-8 hours daily minimum; 8+ hours preferred for best blooming

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Water: Water deeply and regularly, maintaining consistent soil moisture during growing season. Reduce watering once established. Average rainfall is usually sufficient; supplement only during drought. Overwatering can lead to root rot.

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Spacing: 12 inches

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Days to maturity: 70-90 days from seed to first bloom

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Planting depth: 1 inch

Soil

Type: Well-draining loamy soil with moderate fertility

pH: 6.0-7.5

Amendments:

Compost Peat moss or coconut coir Perlite for drainage Balanced fertilizer (10-10-10)

Growing Zones

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Thrives in zones 2-11; annual flower grown everywhere as warm-season bloomer

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a

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Growth Stages

Seedling

2-3 weeks

Single pair of cotyledons emerges, followed by true leaves. Seedlings are tender and may need protection from strong winds.

Keep soil consistently moist but not waterlogged. Thin seedlings to proper spacing when 2-3 inches tall. Provide gentle light and protect from cold temperatures below 50°F.

Vegetative Growth

4-6 weeks

Rapid stem elongation and leaf development. Plant develops sturdy main stem with lateral branching. Growth is vigorous with deep green leaves.

Stake taller plants early to prevent wind damage. Apply balanced fertilizer every 3-4 weeks. Ensure consistent watering. Monitor for pests.

Bud Development

2-3 weeks

Flower buds begin forming at stem terminals and branch tips. Buds appear as small green swellings that gradually enlarge.

Shift to lower-nitrogen, higher-phosphorus fertilizer to promote flowering. Continue consistent watering. Remove competing side buds if larger central flowers are desired.

Flowering

4-8 weeks per plant; successive blooms extend season

Double flowers open with fully petaled, rose-like blooms in soft pink to mauve. Flowers are approximately 3-4 inches across with no visible central disc.

Deadhead spent flowers to encourage continuous blooming. Ensure adequate water during peak flowering. Support heavy flower heads with stakes if needed. Cut flowers in early morning for best vase life.

Seed Development & Decline

2-4 weeks until plant senescence

Petals fade and drop. If flowers are not deadheaded, seed formation occurs (though seed viability is low in double varieties). Plant energy redirects to seed development.

Allow some flowers to mature for seed if desired. Most double flowers produce little viable seed. Continue watering to extend plant life. Remove spent plants in late fall.

Companion Planting

Plan your garden →

Plant with:

Zinnias Cosmos Marigolds Lavendar Russian sage Coreopsis Black-eyed Susans Salvia Verbena

Avoid planting near:

Fennel Dill Potatoes Brassicas (cabbage, broccoli) Beans (which may reduce their nitrogen fixation)

Common Pests

Hand-pick beetles early in season. Use row covers on young plants. Neem oil or spinosad sprays if infestation is heavy. Encourage beneficial insects.
Spray with strong water stream to dislodge. Apply insecticidal soap or neem oil. Encourage ladybugs and lacewings. Avoid excess nitrogen fertilizer.
Increase humidity by misting. Spray with water or neem oil. Ensure adequate watering as drought stress worsens infestations.
and
Remove and destroy affected plant material. Use row covers when moths are active. Encourage parasitic wasps.
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Remove debris where they hide. Use slug baits or barriers. Hand-pick in evening. Beer traps or copper tape around plants.

Uses

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Cut Flowers for Arrangements

Culinary

Astra Rose sunflowers are exceptional cut flowers with a long vase life of 10-14 days. Their unique double-petaled, rose-like blooms and soft pink coloring make them perfect for wedding arrangements, bouquets, and floral design. [source]

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Garden Focal Points

Household

These medium-height sunflowers (24-30 inches) serve as excellent focal points in flower beds, cottage gardens, and mixed borders. Their unusual double flowers attract attention and create visual interest throughout the growing season. [source]

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Pollinator Support

Wildlife

While double flowers produce less nectar and pollen than single varieties, they still attract bees, butterflies, and other pollinators. The blooms provide food sources during mid to late summer when other flowers may be fading. [source]

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Dried Flowers

Craft

Astra Rose flowers dry beautifully and retain their color well, making them ideal for dried flower arrangements, crafts, and long-term floral displays. Hang-dry upside down in a cool, dry location for 2-3 weeks. [source]

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Traditional Herbal Use

Medicinal

Sunflower petals have been used in traditional herbal medicine and tea preparations. While primarily ornamental, Astra Rose petals can be dried for herbal tea or incorporated into natural remedies. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

Cut flowers in early morning when stems are fully hydrated, just as the flower opens or at preferred fullness. Cut at a 45-degree angle using clean, sharp shears. Flowers are long-lasting, typically holding 10-14 days in a vase with fresh water and floral food. To encourage more blooms, deadhead spent flowers regularly. For seed collection (though low in double varieties), allow flowers to dry on plant, then cut and dry indoors for 2-3 weeks before extracting seeds.

Fun Facts

🌱 Astra Rose is a double-flowered mutation of Helianthus annuus, meaning petals have replaced the stamens and pistils, resulting in a pompom-like appearance with no traditional sunflower face.
🌱 Unlike most sunflowers, Astra Rose flowers do not exhibit heliotropism (sun-tracking behavior) due to their fully petaled structure and lack of a developing seed head requiring directional growth.
🌱 The soft pink to mauve coloring is relatively rare in sunflowers; most cultivars are yellow, orange, or red. This unique hue makes Astra Rose highly sought after by florists and flower enthusiasts.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Deadhead Full Sun pH True Leaves

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