Gaura plants can be propagated by taking cuttings or sowing seeds

Cuttings

Take cuttings: During the growing season, cut 5–10 cm lengths of non-flowering shoots from the base of the plant. 

Prepare cuttings: Remove the lowest leaves and soft tip, leaving 2–4 leaves. You can also dip the ends of the cuttings in rooting hormone. 

Plant cuttings: Insert the cuttings into a pot filled with a well-draining compost mix. Space the cuttings a few inches apart. 

Provide warmth and light: Place the pot in a warm, bright location out of direct sunlight. You can cover the pot with a plastic bag to help maintain warmth and humidity. 

Water and monitor: Water the cuttings regularly and check them daily. 

Wait for roots: Roots will emerge from the bottom of the container. 

Pot the rooted cuttings: Gently remove the rooted cuttings and pot them into individual pots. 

Seeds

Prepare the soil: Fill a container with drain holes with seed-starting mix and moisten it. 

Sprinkle the seeds: Sprinkle the seeds sparingly on the soil and cover them with a scant 1/4 inch of the planting medium. 

Provide light and moisture: Ensure your seeds are fresh and viable, and maintain consistent moisture without over-watering. 

Gaura plants grow best in full sun and well-drained soil, but they can also tolerate partial shade and dry soils.