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Guaranteed to Grow
Neonicotinoid-Free
Seed Saver Approved

Black Mammoth Sunflower

Quick Facts:

  • Yellow flowers reach 12" in diameter
  • Towering plants grow 8-10' gall
  • Produces 100's of glossy, black seeds
  • Loved by birds; Makes great chicken feed
  • 110 days to harvest

View full description

Quantity: Packet (50 Seeds)

Get it between -

We ship to all areas of North America including the United States, its territories and outlying islands, and Canada. International orders may incur an additional charge to cover the handling of customs paperwork. Returns are accepted within 30 days of receipt. Full warranty information can be found here.

Black Mammoth Sunflower

More about Black Mammoth

Helianthus annuus

Black Mammoth is an heirloom sunflower variety that is well-deserving of its name.  Towering 8 to 10-foot-tall plants produce giant yellow flowers reaching up to 12 inches in diameter.  At maturity, the colossal heads are loaded with hundreds of glossy black seeds.  We like to toss a few mature heads to our chickens and watch them circle around it frantically gobbling down seeds before the neighboring hen gets them.  Fun for everyone. Blooms mid to late summer.  Each packet contains a minimum of 50 seeds.

Helianthus annuus

Black Mammoth is an heirloom sunflower variety that is well-deserving of its name.  Towering 8 to 10-foot-tall plants produce giant yellow flowers reaching up to 12 inches in diameter.  At maturity, the colossal heads are loaded with hundreds of glossy black seeds.  We like to toss a few mature heads to our chickens and watch them circle around it frantically gobbling down seeds before the neighboring hen gets them.  Fun for everyone. Blooms mid to late su... read more

read less

Helianthus annuus

Black Mammoth is an heirloom sunflower variety that is well-deserving of its name.  Towering 8 to 10-foot-tall plants produce giant yellow flowers reaching up to 12 inches in diameter.  At maturity, the colossal heads are loaded with hundreds of glossy black seeds.  We like to toss a few mature heads to our chickens and watch them circle around it frantically gobbling down seeds before the neighboring hen gets them.  Fun for everyone. Blooms mid to late summer.  Each packet contains a minimum of 50 seeds.

Bucket of heirloom beans
Bucket of heirloom beans

How to Grow Sunflowers

Sunflowers are widely adapted to a variety of climates and are especially tolerant of cold temperatures.  Sunflowers will flourish in a wide variety of soil types, from clay to sandy, so long as sufficient nitrogen is available throughout the growing season.  The water requirements of sunflowers are similar to those of other field crops.  Plants should be irrigated if drought occurs within 20 days of pollination as this period is especially critical for seed development.

After danger of frost has passed, sow seeds 6" apart, 1/2" deep in rows 36" apart.  Germination will occur in 6-10 days.  Thin to one plant every 24" once seedlings have reached six inches tall. Can also be started indoors 4 weeks before the average last frost date.

Transplant outdoors after danger of frost has passed.  Plants should be spaced 18-24" apart to provide for ample air flow.

Sunflowers are susceptible to a number of common diseases including verticillium wilt, mildew, leaf spot, and rust.  However, the extent of these diseases is usually not of consequence to the home gardener.  Ensuring adequate airflow by thinning plants to the recommended spacing will reduce the incidence of disease and cultural practices such as crop rotation, tillage and removal of plant debris in the fall will limit its spread.

Sunflowers make great cut flowers. They are long-lasting and have a bright, cheerful appearance that adds a cheerful touch to any bouquet or arrangement. Sunflowers are also easy to care for, and can last up to a week when cut and placed in a vase with fresh water. When harvesting fresh cut flowers, cut the main head just before it blooms to encourage additional blooms on side shoots. Harvesting flowers in the morning will prevent premature wilting.

CONSIDERATIONS:

Sunflowers are outbreeding plants, relying on bees and other insects for their pollination. Varieties may be self-compatible or self-incompatible, meaning that pollen must be moved from one plant to another. Plants of different varieties must be isolated by 1/2 to 3 miles, depending on the population size and insects in the area, to maintain varietal purity. Hand pollination can be performed by bagging heads and rubbing the flowers of adjacent plants together each day for 10 consecutive days. Heads should be re-bagged after pollination to prevent pollen contamination and predation by birds.

HARVESTING SEED:

SEED LONGETIVITY:

Sunflower seeds can remain viable for up to five years if stored in a cool, dry place.

Arikara Sunflower

Customer Reviews

Based on 8 reviews
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J
Julia K.
Fast delivery

I have not planted the seeds yet, but the delivery was fast. I am going to plant it for the fall crop, and will let you know how it goes.

S
Seth

Great germination. Can’t wait to see fully grown.

D
Dave
Amazing giant beauties

Novice gardener in year four or five, Zone B6, central Connecticut. I planted these seeds pretty late, around May 15th. All the seedlings were eaten by our herd of wild rabbits. Planted again around end of May with protection. They skyrocketed! most were about seven feet tall, but one grew at least ten feet tall and had a huge head. These sunflowers are simply magnificent. Cars slowed just so the occupants could gawk! I'm planting twice as many this year. I cannot recommend this variety enough.

E
Elaine Decker
Black Mammoth Sunflowers

I'm in SW Pa, pre-ordered for next year due to gestation period. But grew one in my home with a heat lamp, it grew huge!! Every seed looks healthy and can't wait to plant multiple next year outdoors where I believe they will prosper better with mother nature!! Highly recommended

E
Emily S Burke
Excellent!

Even taller than expected.

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