Mammoth Sunflower Seeds

Organic, Heirloom

5 out of 5 stars
(5 reviews)
Availability: Out of Stock
This giant among sunflowers is a fast grower whose single stalk can reach 12' tall and produces one 10"-12" flower! Not fussy about soil, it's very easy to grow and drought tolerant. Grow in a tight row to make an attractive screen. Sow monthly for continual bloom into fall. Edible, gray-striped seeds invite birds in the fall (if you don't eat the seeds first!). Edible, bittersweet petals make a sunny garnish on salads and appetizer plates. Attracts pollinators.
Now available in larger packet!
$2.69 8 grams

Botanical Name: Helianthus annuus

Family: Asteraceae

Native: North America

Hardiness: Annual

Plant Dimensions: 6'–12' tall

Variety Information: Up to 12"-wide flowers with yellow petals and a brown center. Single type.

Exposure: Full sun

Bloom Period: Summer to frost

Attributes: Attracts Pollinators, Cut Flower, Drought Tolerant, Heat Tolerant

When to Sow Outside: RECOMMENDED. 1 to 2 weeks after your average last frost date.

When to Start Inside: 2 to 4 weeks before your average last frost date. Sunflowers are senstive to root disturbance; sow in biodegradable pots that can be planted directly in the ground.

Days to Emerge: 10–15 days

Seed Depth: ¼"–½"

Seed Spacing: A group of 3 seeds every 24"

Thinning: When 3" tall, thin to 1 every 24"

Harvesting: Seeds are ready to harvest when the back of the head has dried and turned brown, about 4 weeks after the flowers have been pollinated. Petals will have wilted and fallen off, and the seeds will be plump, and colored white with gray/black stripes. Seeds ripen around the outside of the flower first; the ones in the center will ripen last. Average yield is approximately 1 pound per head.

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Mammoth Sunflower Seeds Reviews

5 reviews

A towering beauty and a hit with the birds

5 out of 5 stars Jul 23, 2018
Our wild lovebirds of Phoenix anxiously await the emergence of these tasty seedheads every July.. August.. September.. and October. Successive sowings of this reliable producer will guarantee enough for the birds - and enough for you, too! Large, meaty seeds from vibrant, mesmerizing and cheerful flowers. Strong stems too, which make great supports for Grandpa Ott's morning glories and moonflowers as well!
Ariel L Driver from AZ


5 out of 5 stars Aug 11, 2020
While most didn't reach 12 feet tall, more like 9-10, I had at least two that were huge. The pollinators LOVED them. I grew twelve plants, and during the 2-3 weeks they were blooming, they were quite the sight in my garden! I am anxious to try the seeds, although if truth be told I grew them primarily for my chickens and the pollinators. I grew them in poor soil, didn't water them, and half of them (I planted them early) were hit with a hard frost in May. I had covered them with cloches, but I think it provided minimal protection. They had a great germination rate, but I started them all indoors.
Anna from PA

Felt like Alice in Wonderland

5 out of 5 stars Nov 7, 2021
The are huge!! Definitely want to have some type of support to help them stand. Beautiful and proficient seeds.
Amanda from ID

Giant sunflowers

5 out of 5 stars Nov 27, 2021
These are big and beautiful. Best when started in the ground.
Holly from MO

Mammoth Sunflower Seeds are Amazing

5 out of 5 stars Jan 15, 2022
Planted these in 2 different areas of garden, in the north sides of the beds so they wouldn't shade other plants. They grew quickly, had huge heads and we so enjoyed watching them get tall, get their beautiful golden heads, then even when the neighborhood squirrels found a way to get to the seeds they were fun to watch. Our granddaughter loved them so much she had us take her senior pictures out there with her holding one. Will definitely buy these again.
Cheryl from CO

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