To propagate phlox, the most common method is division, where you dig up an established plant in early spring, separate the root ball into smaller sections, and replant each piece individually; you can also propagate phlox by taking stem cuttings in the spring before flowering, removing lower leaves, and rooting them in a pot with moist potting mix; for creeping phlox, you can also take root cuttings in winter by digging up the plant and planting short sections of fleshy roots horizontally in a pot.
Key points about propagating phlox:
Best time to divide: Early spring, just as new growth begins to appear.
Taking cuttings: Take stem cuttings about 4-15cm long with a few nodes, remove lower leaves, and plant in a pot with well-draining soil.
Root cuttings: Dig up the plant in winter, cut fleshy roots into 5cm sections, and plant them horizontally in a pot.
Planting new divisions: Ensure each new plant has a healthy root system and shoots, and replant at the same depth as the original plant.