Few flowers bring as much summer into the bed as the sunflower. It grows fast, blooms lavishly and magically draws bees, bumblebees and, later, birds. And because its seeds are so large that small hands can sow them with ease, it is the perfect first gardening project.
Yet a sunflower is not just a sunflower. Before you sow, it is worth a look at the variety, because a three-metre giant wants different handling from a dainty cut-flower type for the vase.
Giant or cut-flower variety?
The sunflower (Helianthus annuus) comes in two basic directions. The giant varieties stake everything on a single, huge head that rises on an arm-thick stem to over three metres. From it you later harvest the fat seeds for birds and the kitchen.
The cut-flower varieties branch strongly and form many smaller blooms over weeks. Many are deliberately bred to be low in pollen, so they do not shed onto the tablecloth in the vase. For a summer bouquet from your own garden they are the first choice. In between there are dwarf and ornamental varieties in red, brown and lemon yellow.
How to grow sunflowers
Sow straight into the bed
Lay the seeds about 2 to 3 cm deep right where they are to grow, from mid-May, roughly CW 16 to 20. Pre-growing is unnecessary; they catch up and root best sown direct.
Protect seedlings from slugs
The tender seedlings are a slug magnet. Protect them in the first few weeks; after that the plant is robust enough.
Place in full sun and support
Choose the sunniest spot in the garden. Tie tall varieties to a sturdy stake early, so they do not snap over in the wind or under the heavy head.
Water in heat
Sunflowers root deeply and cope with drought better than many summer flowers. In long hot spells and in pots you still water regularly.
Harvest seeds or leave them standing
Once the back of the head is yellow-brown and the seeds are plump, you can cut the head and dry it. Or leave it standing, and in autumn the birds help themselves.
Seeds for birds and the kitchen
What looks like a dark pattern in the centre of the bloom is hundreds of tiny individual florets. Each pollinated one becomes a seed. That is exactly what makes the sunflower so valuable at the end of the season.
Sow direct, place in full sun, tie tall varieties up. And in the end you share the seeds with the birds.
The core rule for sunflowers
Frequently asked questions
When do I sow sunflowers?
Straight into the bed from mid-May, around CW 16 to 20, once no more frosts threaten. The seeds germinate fast and reliably in warm soil.
Why does my sunflower topple over?
Usually because of the heavy head and too weak a support. Tie tall varieties to a sturdy stake early. Too shady a spot also makes the plants grow thin and unsteady.
Which sunflower is right for the vase?
Branching cut-flower varieties, ideally deliberately low in pollen. They carry many blooms and do not shed onto the table. Cut them just as the flower is opening.
When are the seeds ripe?
When the back of the flower head turns from green to yellow-brown and the seeds are plump and firm. Then harvest the head and dry it upside down, or leave it to the birds.
Does the sunflower really turn with the sun?
Only the young buds. During the day they follow the sun from east to west and swing back at night. Once the flower is fully open, it stays fixed facing east.
