To propagate Vinca minor (periwinkle), the easiest method is by taking stem cuttings: select healthy, non-flowering stems, cut just below a node, remove lower leaves, and plant the cutting in moist soil with a rooting hormone; you can also propagate by dividing established plants in early spring or fall, separating sections with roots and planting them individually. 

Key steps for propagating Vinca minor with stem cuttings:

Choose healthy stems: Select non-flowering stems with a few nodes (bumps where leaves grow). 

Take cuttings: Use sharp shears to cut a 4-6 inch section just below a node. 

Remove lower leaves: Strip off any leaves that would be below the soil line. 

Apply rooting hormone (optional): Dip the cut end in a rooting hormone powder 

Plant cuttings: Insert the cuttings into a pot with well-draining potting mix, ensuring the nodes are buried in the soil. 

Provide proper care: Keep the soil moist and place the pot in a bright, indirect light location. 

Propagating by division:

Dig up the plant: Carefully lift the established Vinca minor plant from the ground. 

Separate sections: Use your hands or a sharp knife to divide the plant into smaller sections, ensuring each section has roots attached. Repot divisions: Plant the individual sections in new locations with proper spacing. 

Important points to remember:

Best time to propagate: Early spring or late summer are ideal times for taking cuttings and dividing Vinca minor. 

Root development: Be patient, as it may take a few weeks for roots to develop on cuttings. 

Check for invasive potential: In some regions, Vinca minor can become invasive, so be sure to plant it in a contained area.