After a sunflower has flowered its seeds can be harvested for planting again the following year. A single seed planted in the spring can produce many seeds in the autumn and these can be extracted from the seed head once a sunflower has dried out. Signs that a sunflower is drying out include the flower drooping, petals falling away and the back of the flower turning brown.
Sunflowers can be left to dry out on the stem or may be cut down and dried say by hanging the seed head upside down from a nail. As birds and animals eat sunflower seeds, the seed heads may need to be protected during this time, say by putting them in a paper bag. If you have a lot of seeds you can of course share your seeds with wildlife too.
Sunflower seeds are protected by a layer of pollen which is easily brushed away to reveal the seeds underneath. Seeds that are ready for harvesting will look plump, feel hard and come away easily from the seed head by rubbing them with your hand or if you have more than one seed head try rubbing them together to release the seeds – you may want to do this outdoors as there may be bugs in the seed head. If you are concerned about dirt or bacteria, rinse your seeds under a tap, then leave them to dry.
Once harvested, seeds should be stored in a dry place, say an envelope, a box or a paper bag, until you are ready to plant them. If you harvest more than one variety of seed don’t forget to keep these separate and label them so you remember what they are when you come to plant them.