To propagate Snakeroot (specifically White Snakeroot, “Ageratina altissima”), the most common method is by taking stem cuttings from new growth, which readily root when planted in a suitable potting mix; you can also propagate it by dividing established plants or sowing seeds, but be cautious as the plant is poisonous and should be handled with care. 

Key points about propagating Snakeroot:

Stem cuttings:Take cuttings from healthy, new growth during the growing season. 

Cut stems into sections with a few nodes (leaf junctions).  Remove lower leaves and dip the cut ends in rooting hormone.  Plant cuttings in a moist, well-draining potting mix.  Keep cuttings in a warm, humid environment until roots develop. 

Division: Carefully dig up established plants in early spring. 

Separate the root clumps into smaller sections, ensuring each division has healthy roots and shoots.  Repot each division in fresh soil. 

Seed propagation: Collect seeds from mature flower heads in late summer or fall. 

Sow seeds in a seed starting mix indoors.  Transplant seedlings outdoors after the last frost. 

Important considerations:

Toxicity: White Snakeroot is highly poisonous to livestock and can be harmful to humans if ingested. Always wear gloves when handling the plant and avoid planting it where animals or children can access it. 

Check local regulations: In some areas, White Snakeroot is considered an invasive species and its propagation might be restricted.