Growing Sunflower

helianthus annuus : Asteraceae / the daisy family

Jan F M A M J J A S O N Dec
        P P            

(Best months for growing Sunflower in USA - Zone 5a regions)

  • P = Sow seed
  • Sow in garden. Sow seed at a depth approximately three times the diameter of the seed. Best planted at soil temperatures between 50°F and 86°F. (Show °C/cm)
  • Space plants: 8 - 18 inches apart
  • Harvest in 10-11 weeks.
  • Compatible with (can grow beside): Cucumbers, Melons, Sweetcorn, Squash
  • Avoid growing close to: Potatoes

Your comments and tips

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23 Jun 18, Susie (USA - Zone 8b climate)
When is the last month I can successfully plant Mammoth Sunflower seeds in my zone 8b?
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25 Jun 18, (USA - Zone 8b climate)
I asked that question in a FB garden group and they said to plant now
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18 May 18, Carol Graf-Haslam (USA - Zone 10b climate)
When should I plant Mammoth grey stripe sunflower seeds? I live in Southwest Florida and the temperature can range from 32 for a few hours during the winter with highs in the mid to Upper sixties but starting in April the temperature goes into the 90 +range. Should I plant them in October or November 4 a January crop or plant them in March for a May crop? I don't want them to burn and I don't want them to freeze. Please help. Thank you and I am glad to see that the friends in South Africa are also in the same predicament as I am.
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13 May 18, (South Africa - Semi-arid climate)
why sunflower is a popular crop option in marginal areas of South Africa
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14 Apr 18, Therese Elizabeth Ries (Australia - sub-tropical climate)
Hi I have planted and grown with some success King Sunflowers . When they have finished flowering and the heads start to drop , should I cut off their heads to dry out the seeds for sowing for the next season ?
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16 Apr 18, Mike (Australia - tropical climate)
Let the plant die back a bit before cutting the seed head off.
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20 Apr 18, Carol (Australia - cool/mountain climate)
Watch out for parrots/cockatoos though! Tie a lightweight fabric bag over the head while you wait for the plant to die back and the seeds to dry
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29 Oct 17, Laura George (New Zealand - temperate climate)
Could you please let me know - How big are the flowers on Drawf Big Smile and Primrose Queen F.1. Hybrid, we need them, about the size of a hand, say approx 14cm x 12cm??? For a wedding on 5th February 2018. We were going to plant them around 4th - 11th November, is that too early??? I would really appreciate your help. Thank you Laura
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27 Dec 18, Scott (New Zealand - sub-tropical climate)
May depend a bit on the variety of sunflower. Giant Sunflowers grow to a height of 6 feet so they will shade out dwarf beans. Large sunflowers are also gross feeders so will suck up all the nutrients from the soil so ideally need their own space. Hope this helps. Happy Gardening
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02 Oct 17, Jan Brand (South Africa - Summer rainfall climate)
What fertiliser is best for growing sunflowers? Do they also need more potasium? Please help!
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Showing 81 - 90 of 171 comments
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I transplanted 4 sunflowers from seedling pots and they grew very well. They were about 10cm tall when I did this.

- Tony

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This planting guide is a general reference intended for home gardeners. We recommend that you take into account your local conditions in making planting decisions. Gardenate is not a farming or commercial advisory service. For specific advice, please contact your local plant suppliers, gardening groups, or agricultural department. The information on this site is presented in good faith, but we take no responsibility as to the accuracy of the information provided.
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