To propagate a Sweetgum tree, the most common method is to grow it from seed, as propagating through cuttings can be challenging; if you want to try cuttings, take semi-hardwood cuttings in late spring to early summer, remove lower leaves, dip the cut end in rooting hormone, and plant in a well-draining potting mix, keeping the soil moist and providing high humidity to encourage root development; remember that success with cuttings can be variable. 

Key points about propagating Sweetgum:

Seed collection: Gather mature “gumballs” (seed pods) in late fall when they are brown and dry, then separate the seeds from the pods. 

Stratification:

To improve germination, place the seeds in a moist paper towel and refrigerate for a few months to mimic winter conditions (cold stratification). 

Planting seeds:

Sow seeds in a pot with well-draining soil, covering them lightly with soil and keeping the soil moist. 

Cuttings (if attempting):

Timing: Take semi-hardwood cuttings in late spring to early summer. 

Cutting size: Aim for 6-8 inch cuttings with a few leaves at the top. 

Rooting hormone: Dip the cut end in rooting hormone to stimulate root growth. 

Planting medium: Use a well-draining potting mix. 

Care: Place the cutting in a humid environment with bright, indirect light and maintain consistent moisture.