To propagate a Nectarine tree, the most common method is to grow it from seed by removing the pit from a ripe fruit, soaking it in water, then planting it after a period of cold stratification; however, this method may not produce a tree with fruit identical to the parent tree as most nectarines are hybrids, so taking a cutting from a desired variety during late spring to early summer and rooting it with rooting hormone is often preferred for guaranteed genetic consistency. 

Key steps for propagating a Nectarine from seed:

Extract the seed: Remove the pit from a ripe Nectarine fruit.

Soak the seed: Place the seed in a bowl of water and soak overnight.

Cold stratification: Wrap the seed in a damp paper towel and store in the refrigerator for a few weeks to mimic winter conditions.

Plant the seed: Once the seed has gone through cold stratification, plant it in a pot with well-draining soil. 

Key steps for propagating a Nectarine from cuttings:

Select the cuttings: Choose healthy, semi-hardwood cuttings from a current season’s growth, ideally taken in late spring to early summer. 

Prepare the cuttings: Cut the stems into 6-8 inch sections with a sharp knife, ensuring each cutting has a few buds. 

Remove lower leaves: Remove the leaves from the bottom inch or two of the cutting. 

Apply rooting hormone: Dip the cut ends of the cuttings in rooting hormone powder. 

Plant the cuttings: Insert the cuttings into a moist potting mix specifically formulated for rooting, and place them in a warm, humid environment. 

Important considerations:

Variety selection: If you want to ensure the new tree produces fruit identical to the parent plant, choose a named variety and propagate it from a cutting instead of seed. 

Root development: Rooting cuttings can take time and require consistent moisture and warmth. Air layering: For established trees, air layering can be used to create new plants from a branch of the parent tree.