Mammoth Sunflower is a show-stopping annual that grows 6 to 12 feet tall, producing flower heads that stretch 12 to 24 inches across. Hardy across zones 2 through 11, these giants bloom in 75 to 90 days and thrive in full sun with moderate water and neutral soil. The flowers track the sun's movement throughout the day, attracting pollinators while producing edible seeds that birds and gardeners alike will treasure. Dried stems become beautiful craft material once the growing season ends, making this variety as useful after harvest as it is spectacular in the garden.
Full Sun
Moderate
2-11
144in H x ?in W
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Moderate
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These giant blossoms sit atop stems that rival many trees, creating an unforgettable garden presence that makes anyone smile when they see it. The flower heads grow massive, 12 to 24 inches in diameter, and attract butterflies and bees in abundance. Beyond their visual drama, sunflowers yield delicious edible seeds and require very low maintenance once established. After the season, the sturdy stems dry beautifully for craft projects, extending the value of this variety well beyond the growing season.
Mammoth Sunflower is grown primarily for its spectacular flowers, which attract pollinators to the garden and create stunning focal points in landscape design. The mature seeds are edible and can be harvested, dried, and eaten fresh or roasted. Dried stems have long been valued for flower arranging and crafts, offering utility beyond the blooming period.
No timeline data available yet for this variety.
Start seeds indoors 2 to 4 weeks before your average last frost date. Sunflowers are sensitive to root disturbance, so sow in biodegradable pots that can be planted directly in the ground without transplanting shock.
Transplant outdoors 2 to 4 weeks before your average last frost date. Since sunflowers resent root disturbance, plant the entire biodegradable pot directly into the ground rather than removing the seedling.
Sow seeds outside 1 to 2 weeks after your average last frost date. Direct sowing is the recommended method and often produces vigorous plants.
Harvest seeds after the flower petals have dropped and the back of the flower head turns from green to yellowish-brown. Cut the entire head from the stem, leaving 6 inches of stem attached, and hang it upside down in a warm, dry location to finish drying. Once fully dry, rub your hand over the seed face to dislodge the mature seeds.
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