Harvesting annual sunflowers is quite important if you intend to grow another crop the following year. It is quite easy to tell when a sunflower is ready to harvest because the flower head should have wilted facing down and the back of the head turns a yellow or brown colour. You don’t want to leave them in this state for too long because if you have some wet weather they can be susceptible to mould and if you have some warm weather they can dry out quickly and the seeds can fall on the floor and be lost or eaten.
You’ll need to chop the head off the plant using some secateurs or strong scissors about 6 inches down the from the top of the stem. You can leave the head of your plant in a well ventilated and dry place to dry out for up to a week before you extract the seeds. This will make the seeds hard and easy to remove.
If you are growing different varieties of sunflowers it is a pretty good idea to label your drying heads as they can tend to look quite similar at this stage. You might also want to make a note if they had grown to a certain size or had a rather striking colour which you liked so you know which seeds in particular you would like to grow the following year.
To collect the sunflower’s seeds you need to first brush off all the mature disc florets from the face of the sunflower head with your fingers.
With the seeds now exposed press your thumb down firmly and move it in a circular motion and they will eventually come loose and start to drop out. Once you have created a gap they will start dropping out more easily.
If you are harvesting your seeds to save for future generations of sunflowers then the seeds you want to concentrate on collecting are the larger ones from around the edge. The seeds in the centre tend to be smaller and would not have such as good yield.
Place your newly harvested seeds into paper envelopes not forgetting to note the variety and keep in a dry location. Do not put your seeds in a plastic bags. When you feel your seeds have completely dried you can place your envelopes into an air tight container until you need them to plant the following spring.