Late summer gardens are crowned by sunflowers with towering stems, golden flowerheads, and whorls of visiting bees, making borders feel sunlit even on grey days. They’re popular because they’re easy to grow from seed, generous with nectar and pollen, and spectacular in everything from cottage borders to patio pots. Most UK sunflowers bloom from July through September, peaking in August.
By early to mid-September, petals fade and heads droop as seeds mature, which is exactly when saving them makes sense. The Royal Horticultural Society notes that once the flower has faded, the central head is packed with seed, and “these are a great source of food for birds”. Natural food supplies for birds can be hit and miss, with berries and seeds sometimes abundant and sometimes scarce after dry spells.
The Wildlife Trusts highlight that garden plants with berries and seedheads become a larder “particularly in late summer and autumn,” yet gaps still open as daylight shortens.
Migrant birds like redwings and fieldfares arrive needing quick calories, while local tits, finches and robins build fat reserves for chilly nights. By starting in autumn, gardeners can help young birds learn safe feeding routes before the harsher weeks arrive.
The National Trust recommends leaving seed heads on during winter to feed birds, but collecting seeds to supplement your bird feed is easy if you want to remove dull sunflowers from your garden.
Following the RHS’s advice is straightforward: “Once the petals have faded, cut the flower heads off and store them in a sunny, warm, dry place for another week.”
Then, “Spread a sheet of newspaper on a flat surface, gently rub the seed head and the seeds will fall away easily,” which makes processing quick, even for big heads.
All sunflower varieties are edible, but the larger, grey and white striped seeds are more meaty and flavorful than the smaller, dark oilseed types.
If you want to save some seeds for replanting, collect them in an envelope or paper bag and store them in a cool, dry and dark place until spring, when they will be ready to sow and grow once more.
As Laura of House Plant House adds, “Always make sure your saved seeds are not where birds can get at them and that they don’t rot from too much moisture.