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Mammoth Sunflower

Mammoth Sunflower

1039

5.0
Rated 5.0 out of 5 stars
18

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.

$2.99
$2.99
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~8.0 g

(~70 seeds)

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  • Variety Info
  • Sowing Info
  • Growing Info
  • Learn More

Variety Info

Family: Asteraceae

Type: Sunflower (Learn more)

Native: North America

Hardiness: Annual

Exposure: Full sun

Bloom Period: Summer to frost

Plant Dimensions: 6'–12' tall

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

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

Non GMO Project

Sowing Info

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"

Your hardiness zone is

Growing Info

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.

5.0
Rated 5.0 out of 5 stars
Based on 18 reviews
Total 5 star reviews: 18 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
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18 reviews
  • Mary O.
    Verified Buyer
    Rated 5 out of 5 stars
    11/6/24
    5 Stars

    I planted five, and as you can see all five grew. I think they would be taller except I didn’t get them transplanted soon enough, and I also didn’t choose a sunny enough location. I am still thrilled that they all grew and they all have flowers coming! I will be planting them again next year, just in a different location and probably directly in the garden.

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  • Erle R.
    Verified Buyer
    Rated 5 out of 5 stars
    8/3/24
    5 Stars

    It was very easy I’m 15 and this is my first gardening season and just put these in the ground and watched them grow. Did plant these in front of my peppers which is my mistake but these are growing very well.

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  • Tanya S.
    Rated 5 out of 5 stars
    6/4/24
    5 Stars

    This is my first time growing these. Oh what fun! They are close to if not about 10 feet tall. I can't wait to harvest the seeds.

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    Which best describes you as a gardener? Intermediate
  • Connie M.
    Verified Buyer
    Rated 5 out of 5 stars
    6/3/24
    5 Stars

    These mammoth babies emerged after just 5 days! I'm excited!

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  • Loris M.
    Verified Buyer
    Rated 5 out of 5 stars
    5/4/24
    5 Stars

    I have 4 kinds of sunflowers sprouting in the recycled cardboard pots. I'm hoping to plant these without disturbing the roots. The ones on the right are the Giant Mammoth.

    Was this helpful?
    Which best describes you as a gardener? Beginner