Growing Sunflower

helianthus annuus : Asteraceae / the daisy family

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

(Best months for growing Sunflower in Australia - tropical regions)

  • S = Plant undercover in seed trays
  • T = Plant out (transplant) seedlings
  • 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 10°C and 30°C. (Show °F/in)
  • Space plants: 20 - 45 cm apart
  • Harvest in 10-11 weeks.
  • Compatible with (can grow beside): Cucumbers, Melons, Sweetcorn, Squash
  • Avoid growing close to: Potatoes
  • Sunflowers
  • Young plants

Sunflowers need full sun and grow best in fertile, well-drained, moist soil with plenty of mulch. Sunflowers do not like to be transplanted so are best grown direct from seed. The giant or Russian varieties are preferred for seed production.

Grow to 1 - 2 metres (4 - 6 ft) so need staking or protection from the wind. Protect seed heads from birds when ripening with nets or paper bags. Chickens love a sunflower head hung for them to peck!

Culinary hints - cooking and eating Sunflower

Use seeds fresh or toasted or press for oil.

Your comments and tips

12 Apr 23, Chris Harcoan (Australia - temperate climate)
When is the best time to plant sunflowers in Mildura Victoria...
24 Mar 23, Wayne Thresher (New Zealand - temperate climate)
I lost most of my crop to the wet chill weather this past summer. I'll have to buy chook feed this year. Can anyone recommend the hardiest crop that can tough out changing climate. rainy, windy wet cold ... nevermind... I'm moving :) Same question for maize if you have knowledge
27 Mar 23, (Australia - sub-tropical climate)
The weather works against us sometimes.
27 Aug 22, Dylinda Matiga (Australia - tropical climate)
I don't think sunflowers like the tropics, I think they need long days to reach full potential If you start them in March they are scrappy if it's too wet they are scrappy. In Sydney they grow huge every variety In the tropics they are scappy, a couple yellow varieties just reach 6ft I'm in Philippines autumn beauty in Sydney is brilliant but here it's scrappy. I'm experimenting year round with some 20 varieties. Helianthus tuberous would be ideal, I can't get it D Every sunflower l know will grow scrapyif planted in autumn, the flower is yuk But if you know of autumn varieties please inform me Cheers D
31 Aug 22, (Australia - tropical climate)
Plant after the wet season. Maybe it is your soil - have good draining soil. Try making a raised row or bed and plant in the top.
27 Dec 20, Tess (Australia - tropical climate)
I live on Horn Island on the tip of Cape York, is the best time to plant the seeds after the wet season in April?
05 Jan 21, Anon (Australia - temperate climate)
Not too many plants like wet soggy soil. Read the notes here.
20 Sep 20, Anita (Australia - cool/mountain climate)
When is the best time to plant giant sunflowers in the Southern Highlands, NSW?
27 Sep 20, (Australia - cool/mountain climate)
Go to cool/mountain climate zone and check the planting guide at the top of the page.
25 Aug 20, Josie (Australia - sub-tropical climate)
Hi! Wondering if it’s too earlie to plant giant Russians , I’m just north of Byron bay in the mountains, nights are still getting below 10 degrees and the soil in my garden is red clay type soil mixed with soil improvers, too cold still?
Showing 1 - 10 of 78 comments

I am trying to grow giant sunflowers from seed I purchased at a reputable seed dealer, I can get a 40% germination rate in seed pots but the seedlings are very leggy and tend to lay down at 7.5cm high. In the ground I did get three to sprout, quite upright about 10cm high but then nothing. No further growth for around around four weeks. What am I doing wrong? Good quality potting soil, slow release in soil and I also use fish emulsion about every 8 weeks. All my other plants in the garden and pots are thriving. Any ideas? Please

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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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