Harvest begins in mid-September and can run into October. A check of the flower head will indicate maturity; florets in the center of the flower disk are shriveled, heads are downturned, and a lemon-yellow color is on the backside. Pull a few seeds and split them with a knife to check if seed meat has filled. Poorly filled seeds may be due to a lack of pollinating insects.

Sunflower seeds are ripe when they fall off the head or the birds start eating them. To prevent loss, cover the heads with a paper sack, cheesecloth or nylon netting once the yellow petals start turning brown. Secure the sack, cheesecloth or nylon netting with a rubber band or twist tie to prevent seeds from dropping. Heads can also be cut with about a foot of the stem attached and hung in a warm, dry, well-ventilated, rodent and insect-free place. Cut the heads once a few seeds start turning the traditional black with white stripes. The flavor will not be as good as those ripened on the plant, but less loss will occur. Once the seed is dried, it can be rubbed easily from the seed heads. Humidity levels must be kept low to prevent spoilage. Sunflower seeds will remain viable for seven years when stored in a cool dry, dark location.

Raw mature seeds may easily be prepared at home by covering unshelled seeds with salted water (2 quarts of water to ¼ to ½ cups salt). Bring to a boil and simmer two hours or soak in a salt solution overnight. Drain and dry on absorbent paper.

Put sunflower seeds in a shallow pan in a 300-degree F oven for 30 to 40 minutes or until golden brown, stirring occasionally. Take out of oven and add one teaspoon of melted butter or margarine to one cup of seeds. Stir to coat. Put on an absorbent towel. Salt to taste.