One flower, or hundreds?
A sunflower head is not a single flower. The centre is packed with hundreds of tiny disc florets, each a complete flower that can set a seed, and the golden ring around the outside is another set of florets.
Choosing a variety
The genus Helianthus holds about 70 species, and the garden sunflower, Helianthus annuus, has been bred into hundreds of cultivars, so our sunflower seeds run from pot sized plants to giants.
For pots and small beds, try Solstice, Sunny, Teddy Bear, Dwarf Sonnet or Microsun Gold. For height, Sunbird, Giant Single and the Common sunflower will clear a fence. Dwarf Sunsation, at about 40cm, edges a vegetable bed neatly.
When to sow, zone by zone
- Temperate (coastal New South Wales, most of Victoria, settled South Australia): September to January.
- Mediterranean (Perth, the south west of Western Australia, Adelaide, the South Australian gulf country): the same September to January window, watering through the dry summer.
- Cool and alpine (Tasmania, Canberra, the Victorian and New South Wales high country, the New England tablelands): pots in late September, then direct from October to early December once frost has passed.
- Subtropical (south east Queensland, the northern rivers of New South Wales): August to March.
- Tropical (the Top End, far north Queensland, the Kimberley): March to September, through the dry season rather than the wet.
- Arid and semi arid (inland New South Wales, Queensland and Western Australia, the Mallee, the Alice Springs country): late August to November and January to March, skipping peak summer heat.
These are broad groupings rather than hard borders, so if you garden between two of them, lean on your own local frost dates.
Sowing and spacing
Sunflower seed is large, and soaking is optional. Sow 20 to 25mm deep where the plants are to grow, because sunflowers dislike root disturbance. Under cover, use deep cells and plant out while small.
Space dwarf types about 30cm apart and tall types 45 to 60cm. Crowded plants give thin stems and small heads.
Why the heads face east
Young sunflowers do follow the sun. The stem grows faster on one side than the other, swinging the bud east to west through the day, then back overnight. It runs on the plant's own daily clock, not on the sun pulling it around.
Once the head opens, stem growth stops and so does the tracking, which is why mature heads stay facing east. It is not the weight of the head. East facing heads warm earlier, and warm heads tend to attract more bees.
Sunflowers in the vegetable garden
Sunflowers pull in beneficial insects, and pests with them. Many insects are drawn to yellow, so expect bees and hoverflies, and expect aphids. Ladybirds usually follow, and left alone they do most of the clean up.
A strong stem makes a good living trellis for cucumbers and other light climbers, and tall sunflowers throw useful afternoon shade over lettuce in summer. They will not make cucumbers taste sweeter: sweetness comes down to variety, steady water and picking at the right size.
Sunflowers also make life harder for some neighbours. The roots, and old stems as they break down, release compounds that can slow the growth of young seedlings, so compost spent stalks rather than digging them into a bed about to be sown.
Harvesting the seed
You can eat sunflower seed, although it is only worth the work with large seeded types such as Giant Russian, Giant Single and the Common sunflower. Let the head dry on the plant, and cover it with a paper bag once the seeds fill out, or the birds will get there first.
What you buy in a shop is the kernel. The whole seed is an achene, and the striped hull comes off before you eat it. Rub the dried head to loosen the seed, dry it fully, then store it in a jar.
Related growing guides
- Sunflowers from Seed: A Complete Australian Growing Guide (Including the Sunbird Variety)
- Companion planting in Australia: what really helps, and what is folklore
- Stop Growing Vegetables On Their Own: The Flowers That Bring The Bees Your Zucchini Needs
Ready to plant? Browse our Sunflower seeds.