Black Mammoth sunflower in full bloom with bright yellow petals and a large, dark brown seed head against a blurred garden.
Black Mammoth sunflower bud beginning to open with green sepals and a dark center against a blurred garden background.
Bright yellow Black Mammoth sunflower blooms with dark centers growing in a sunlit field.

Black Mammoth - Organic Sunflower Seeds

$5.65
Open-Pollinated
Certified Organic
Quick Facts
  • Towering stalks topped with broad, golden sunflower faces
  • Heavy dark centers fill with abundant seed
  • Grow a garden landmark for birds and seed saving
  • 85–95 days from sowing to bloom
  • Helianthus annuus
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🌱 Sow with Confidence—One-Year Seed Guarantee

Black Mammoth sunflower grows into a towering old-fashioned plant with a broad golden face and a dark center packed with seed. This is the kind of sunflower children remember: tall, sturdy, and almost unbelievable by late summer, standing like a landmark at the garden edge.

Give it full sun, room, and decent soil, and it will reward you with a heavy seed head for birds, seed saving, or simple harvest-season wonder. Plant a row where height is welcome and let it become the backbone of the summer garden.

Orders ship from Pennsylvania within 1–2 business days via USPS. Orders $79+ ship free within the contiguous United States.

Unopened items may be returned within 30 days. If something arrives damaged, incomplete, or incorrect, we’ll make it right.

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We stand behind every packet. Our seeds are untreated, germination-tested, true to variety, and covered for one year from purchase.

If seeds arrive damaged, fail to germinate under reasonable growing conditions, or do not grow true to type, contact us and we’ll make it right with a replacement, store credit, or refund.

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FAMILY OWNED

Hand packed in Pennsylvania by our family.

LAB TESTED

Third-party tested for reliable germination.

NON-GMO

Open-pollinated varieties for home gardens & seed saving.

UNTREATED SEED

Never coated with chemical seed treatments.

Customers rate us 4.8/5 based on 317 reviews.

Sunflower Growing Basics

Sunflowers have become one of the world’s most recognizable garden flowers, producing cheerful blooms that follow the summer sun and provide food for pollinators, birds, and people alike. Native to North America, they have been cultivated for thousands of years for their beauty, edible seeds, and agricultural importance.

Today’s sunflowers range from towering single-stem giants to branching varieties that produce dozens of blooms over many weeks. Whether planted for cut flowers, pollinator gardens, edible seed, wildlife habitat, or simply a striking display of summer color, sunflowers are among the easiest and most rewarding flowers to grow from seed.

Direct sow sunflowers after all danger of frost has passed and the soil has warmed. Their vigorous growth and deep root systems make direct sowing the preferred method for most varieties.

Successive sowings every two to three weeks through early summer provide continuous blooms for bouquets, pollinators, and extended harvests. In regions with long growing seasons, later sowings can still produce flowers before frost.

Sow seeds ½–1 inch deep in well-prepared soil and keep evenly moist until seedlings emerge, usually within one to two weeks under warm conditions.

Because sunflowers develop strong taproots, they establish best when direct sown. Space plants according to the mature variety, with branching types generally requiring more room than single-stem varieties. Protect newly emerged seedlings where birds or wildlife are a concern.

Plant sunflowers in full sun and fertile, well-drained soil. They thrive in warm weather and benefit from consistent moisture while establishing, though mature plants tolerate short periods of drought.

Tall varieties may require staking or support in exposed locations with strong winds. Avoid excessive nitrogen fertilizer, which encourages leafy growth and weaker stems.

Sunflowers are among the best flowers for supporting pollinators, attracting native bees, honeybees, butterflies, and many beneficial insects throughout bloom. As seed heads mature, they become an important food source for birds and other wildlife.

For cut flowers, harvest when the petals have just begun lifting away from the center but before the flower is fully open. Branching varieties continue producing additional blooms throughout the season when harvested regularly.

For decorative seed heads or edible seed, allow the flower heads to mature fully on the plant until the backs turn yellow to brown and the seeds become firm. Protect ripening heads from birds with mesh bags if seed harvest is planned.

Full Sunflower Growing Guide