Allow one or more heirloom nectarines to become very ripe in late summer. Then cut each fruit open and extract the large seedpod. Rinse the seedpods and scrub lightly with a toothbrush or other soft brush.
Dry your seedpods in a warm, dark, dry well-ventilated spot for a few days.
Tap each seedpod, using a hammer, in order to release the actual seed inside. The seed is white and resembles an almond.
Place the inner seeds in a jar or plastic bag in your refrigerator for up to three months.
Plant seeds in pots full of potting soil, inserting them about 1 inch deep. Then keep pots outdoors for the duration of the winter to give them the cold they need in order to germinate.
Remove seeds from their pots and soak them in lukewarm water for 12 hours. Fill a Mason jar with potting soil, moisten it and combine seed with the moist soil. Tightly cover the jar and place it in the refrigerator for an additional month. When you see white roots growing from any of the seeds, remove them from the jar.
Plant your germinated seeds in 1 gallon pots or larger. Give them full sun and keep the soil moist. Transplant to the garden in spring when seedlings are 6 to 8 inches tall.