Growing Sunflower

helianthus annuus : Asteraceae / the daisy family

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

(Best months for growing Sunflower in Australia - temperate 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

Your comments and tips

26 Aug 20, Anonymous (Australia - temperate climate)
I'm sub-tropical and I have seeds germinating now (night temps av around 9-10 (7-14) and day temps around 23-24 (21-28)). Hold off for another week or two and then give it a go. We may have another cold period before winter is finished.
01 Jul 20, Emma (Australia - temperate climate)
Hi, I was hoping for some planting advice, how many seeds in each amount of soil?! Is it a good time to plant the seeds now in winter nice and deep to get the best results come spring time? Thanks Perth WA
06 Jul 20, Anonymous (Australia - sub-tropical climate)
Plant seeds 50-60cm apart and rows 60-80cm apart. You can plant two seeds and then reduce to one after germination. If good seeds just one is required each 60-60cm. Don't plant until spring as you need a lot warmer soil than what it is now. Do not plant seeds deeper than what is suggested.
01 Jun 19, Thushari (Australia - temperate climate)
I had gian Russian sunflowers grown in my garden in Dec. Summer time in Melbourne. It grew nicely. It didn't grow up to 3 m. Only about 1 meyer tall. Big flowers similar to a size of a plate. Again i grew them in Autumn flowering started in late may. Looks like a bit slow considering cool windy weather conditions. I keep them inside ( its in pots) I keep them outdoor only when its Sunny. The name says Russian i assumed it ll grow in.Winter here in Melbourne. But flowering takes a bit longer than I thought. Anyone got good suggestions if I m doing the right thing? One plant I put on the ground it nearly dead due to heavy windy weather. I try to keep room temperature for the plant . Heaters on in my house most of the day. Any ideas most welcome? I grow flowers first time on my life. But really enjoying it. Thanks
04 Sep 19, TempestSkye (Australia - temperate climate)
If growing sunflowers from seed, they really need to be planted in September/October (in Melbourne) at the latest. I found that Giant Russian Sunflowers are very hungry and very thirsty, so in addition to lots of sunshine and warmth, it needs a lot of nutrient rich soil and a decent amount of water to keep it moist (but not too wet) at all times. Mine grew 2-3m in the first year. The second year I had a volunteer sunflower plant grow where they had been growing the previous year. It sprouted late and I didn't give it much help in terms of fertiliser and watering was less often than I had the first year too. It only grew a metre or so high before it succumbed to autumn chill.
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 ?
16 Apr 18, Mike (Australia - tropical climate)
Let the plant die back a bit before cutting the seed head off.
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
06 Dec 16, Narelle (Australia - temperate climate)
I've been trying to get some seeds to germinate, without success. Do you have any advice, please? Perhaps I just need to be more patient, though - had them in a heated propagator for a couple of weeks and now have them out in the sun in a warm box. The temperature I'm keeping them at would definitely be between 10 and 30 degrees C.
07 Dec 16, John (Australia - temperate climate)
Sunflower seed sown directly into the ground should germinate very easily at this time of the year without any heat. Is your seed old? Try again, sowing directly into the ground in a sunny spot. Keep the soil moist but not wet and the seedlings should emerge within 7-10 days. Trust this helps.
Showing 11 - 20 of 78 comments

Garden centre seeds were too expensive so I planted a whole heap of sunflower seeds which we buy from the supermarket for our cockatoo. Now I have got heaps of seedlings all very close to one another. Should I thin them out by transplanting or by pinching out? And what do you reckon is the minimum space I can leave between seedlings. Thanks

- stephen

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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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