Seed Swaps

Sunflower 'Mammoth'     

Helianthus annuus

  • 136 plantings
  • 22 available for swap
  • 5 wanted
  • 138 stashed

'Mammoth' is a Sunflower variety in the Helianthus genus with a scientific name of Helianthus annuus. 'Mammoth' is considered a heirloom cultivar. Blooms appear in these approximate colours:   Golden yellow and   Selective yellow. The mature flowers are of a Single form. Leaves appear approximately as a   Dark olive green and   Dark spring green colour.

This variety attains a height of 8 to 12 feet. Is fast growing and produces a giant bloom. The seed make good bird feeding in the winter.[seed packet Bentley Seeds, Inc.]

To save seeds, cut the stem beneath flower heads when the backs of the flower heads turn yellow. Hang it in a cool and dry place and let it dry. It will take about a month for it to dry. In order to keep seeds from falling on the ground, a net should be used to cover the flower.

It is an Flower and is treated mainly as a Annual, This means that it grows best over the course of a single year. Mammoth is known for its Erect habit and growing to a height of approximately 2.50 metres (8.12 feet). This variety tends to bloom in late summer.

Mammoth Sunflower is normally quite a low maintenance plant and is normally very easy to grow - great for beginner gardeners!

This variety plant info is provided by the myfolia gardener's wiki. All details about Mammoth have been kindly provided by our members.

How to grow Mammoth

  • Full Sun

  • Medium

Water when top 2 inches of soil are dry. Fertilize once or twice while growing. May require staking.

Position in a full sun location and remember to water moderately. Keep in mind when planting that Mammoth is thought of as half hardy, so remember to protect this plant from frosts and low temperatures. Use USDA Hardiness Zone 4 - 9 as your guideline for the appropriate climate for this plant. Ideally plant in loamy and clay soil and try to keep the ph of your soil between the range of 5.7 and 8.1 as Mammoth likes to be in weakly acidic soil to weakly alkaline soil.

Growing Mammoth from seed

Try to aim for a seed spacing of at least 3.96 inches (10.16 cm) and sow at a depth of around 0.99 inches (2.54 cm). Soil temperature should be kept higher than 16°C / 61°F to ensure good germination.

By our calculations, you should look at sowing Mammoth about 21 days before your last frost date.

Transplanting Mammoth

Plant seed outdoors after the last frost when soil temp reaches 60 degrees Fahrenheit. Cultivate and enrich soil with compost. Keep moist until seedlings are established.

Ensure that temperatures are mild and all chance of frost has passed before planting out, as Mammoth is a half hardy plant.

Harvesting Mammoth

Sunflower Mammoth Etymology

The botanical epithet is from the Latin annuus meaning “annual”.1

Mammoth folklore & trivia

First offered by seed companies in the 1800’s.

Other Names for Sunflower 'Mammoth'


Latest Sunflower 'Mammoth' Reviews

  • Tutor installation as they are getting really tall! Some were starting to crack. One of them already did and now it cant hold straight by itself anymore… They were not supposed to need tutor…

    0 stars

    Mr_Uke about growing Tournesol 'Mammouth géant' / Sunflower 'Mammoth' #3,5,7
  • Tutor installation as they are getting really hish! Some were starting to crack. One of them already did and now it cant hold straight by itself anymore… They were not supposed to need tutor, but I guess that growin that big inside made them a bit soft!

    0 stars

    Mr_Uke about growing Tournesol 'Mammouth géant' / Sunflower 'Mammoth'

See all Mammoth reviews and experiences »


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