Internet #300042917

Model #X1540

Sunflower Mammoth Organic Seed


Product Overview

Our Mammoth Sunflowers are stately sunflowers with enormous heads with more than 1 ft. across. They will provide spectacular beauty first and then seeds for roasting or birdfeed. Each plant bears 1 huge, eye-catching bloom. They are excellent for tall blooming backgrounds and screens for unsightly places.
  • Harvest seeds by cutting flower heads when backs yellow, then hang downward in a warm, dry place
  • Kansas state flower
  • Easy to grow
  • Seeds contain no GMOs
  • Germination rates exceed USDA standards
  • Botanical name helianthus annuus
  • Giant of all sunflowers, sometimes reaching 12 ft. tall
  • Thick stalks support the huge heads that tower above the garden
  • Single-stem variety is a very fast and vigorous grower
  • Use Ferry-Morse seed, providing seed to the world that's guaranteed to grow since 1856
  • Click here to learn more about our Healthy Home Eco Options



Mature Height
12 feet
Product Depth (in.)
Product Height (in.)
Product Size
.02 LB-Pound
Product Width (in.)


Landscape Supply Type
Maximum Time to Bloom / Harvest (weeks)
Maximum Time to Germinate (days)
Plant / Seed Spacing (in.)
Seed Type
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Questions & Answers


when is the best time to plant in the northeast (Maine) ?

Asked by Moe June 6, 2020

Thank you for your question. Best time to plant is after all danger of frost has passed and soil temp is in the 70's. For Maine and extreme northern climates that can be up to July. You can plant when soil temp is lower, down in 40's, however the days to germ will take longer. Our best to you this season.

Are these heirlooms? If not, will the seeds they produce be any good?

Asked by Poopypoop April 22, 2020

Thank you for your question and yes Heirlooms, not a hybrid. They will be good to eat or save seed for next season. Our best to you!

How many seeds do you place in each hole

Asked by Richie December 9, 2019

Thank you for your question. Best practice is after all danger of frost place 2-3 seeds per hole, hole spacing should be 18-24 inches apart, cover with 1 inch soil and when plants are 4 inches tall thin by leaving the best plant from each hole. Ensure to pack the soil lightly back around the base of the seedling remaining. If you looking to have several plants in a row what I personally do is use my hoe and with the corner pull it across the soil about 1 inch down to create a trough or line to place seeds in. Place 1 seed every 3 - 6 inches in trough and cover with 1 inch soil. I do this for however many rows of sunflowers I'm going to plant. Rows should be spaced 18-24 inches apart. Once plants are 4 inches tall, thin plants to a spacing of 18-24 inches between each. Hope this helps and if you need further assistance don't hesitate to reach out to our customer service team at 508.285.5800. Our best to you this season.

how many seeds come in this packet?

Asked by valerie September 26, 2017

Thank you for your question, our packets are filled based on seed weight and seed weight can vary by lot number however you should find approximately 50-55 seeds per packet. If you need further assistance don't hesitate to reach out to our customer service team at 508-285-5800. Thanks again and our best to you this gardening season.

Customer Reviews

  • 1 Customer Reviews
  • 5 out of 5 stars overall
100% of customers recommended.
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Sun beauty
Zone 7 here, and I can tell you these get monster tall, hence the word mammoth. They grew so tall that I had to tie them on the 1st floor clothes line! I planted these for a photo-op and they didn't disappoint. The birds had a festive ball with them, so I can't tell you how tasty the seeds may have been. I planted them again this year on the opposite side of the garden.
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