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 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

23 Jun 18, Susie (USA - Zone 8b climate)
When is the last month I can successfully plant Mammoth Sunflower seeds in my zone 8b?
25 Jun 18, (USA - Zone 8b climate)
I asked that question in a FB garden group and they said to plant now
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.
13 May 18, (South Africa - Semi-arid climate)
why sunflower is a popular crop option in marginal areas of South Africa
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
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
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
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!
Showing 91 - 100 of 181 comments

One last thought -- and whether this is a good idea or not will depend on the "tastes" in your area. (using info from the net): The Jerusalem artichoke (Helianthus tuberosus) is closely related to sunflowers. Specialty producers treat Jerusalem artichokes as a very versatile, gourmet root vegetable under multiple names such as Sunchoke (created and trademarked by Frieda Caplan) and lambchoke, as well as sunroot, wild sunflower, earth apple, earth pear, and topinambour (in France and Germany). They have also been called French potatoes, German turnips, and Canadian artichokes or truffles. They can be sliced and eaten raw (after washing the edible skin) and are variously described as sweet, savory, nutty, and crunchy, similar to water chestnuts, jicama, or milder radishes. They are often boiled, roasted, or mashed, with a flavor very similar to potatoes or artichoke hearts. They can also be fermented or pickled, and ground into flour. Jerusalem artichokes look similar to ginger root or turmeric and potatoes. They can be short or long and brown, white, red, purple, or grey in skin color. Wild tubers are often red and plants are spread across fields; when cultivated, they appear white and clustered together. Tubers are oblong, with lumps or knobs. The inside is white until exposed to air when the flesh will begin to darken. More than 200 varieties of Jerusalem artichokes exist including Clearwater, Columbia, Mammoth, Oregon, Red Fuseau, Stampede, and White Fuseau. Jerusalem artichokes are a hardy perennial able to grow well in most soils. Ideally, the ground is loamy, loosely packed, and with a slightly alkaline pH value of around 7. Temperatures between 65 to 80°F (16c - 26 c) are preferred for optimal growth, along with 125 or more frost-free days. More sunlight is needed for the initial growing stages, then less is preferable as the tubers form. Precipitation will aid in growth, especially during sprouting, but too much moisture will waterlog plants. In commercial production, Jerusalem artichokes are raised annually, despite their perennial nature. Growth takes 7 months on average, seeds are often planted in early spring for best yields. ...................... certainly worth thinking about. Sunflowers for oil production probably have more "certainty" when it comes to demand. Sun chokes may not have the demand (initially - or maybe ever) in your area to support a farm dedicated to Sun chokes and Sun Chokes are know for their "delicate" skin which may make shipping tricky (avoiding spoilage)..

- Celeste Arcjer

Please provide your email address if you are hoping for a reply


All comments are reviewed before displaying on the site, so your posting will not appear immediately

Gardenate App

Put Gardenate in your pocket. Get our app for iPhone, iPad or Android to add your own plants and record your plantings and harvests

Planting Reminders

Join 60,000+ gardeners who already use Gardenate and subscribe to the free Gardenate planting reminders email newsletter.


Home | Vegetables and herbs to plant | Climate zones | About Gardenate | Contact us | Privacy Policy

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.
We cannot help if you are overrun by giant slugs.