Nasturtiums can be propagated from seed or by stem cuttings

From seed 

  1. Soak seeds in water for 24 hours to soften the seed coat.
  2. Plant seeds about 1 inch deep in well-draining soil.
  3. Space seeds about 3 inches apart.
  4. Keep the soil moist but not waterlogged.
  5. Seeds should germinate in 7 to 10 days.

From cuttings

  1. Select a stem from a mature nasturtium plant. 

Cut a 4-inch or longer piece with at least three leaves intact.  Pinch off flower buds and remove the lower leaves.  Dip the cut end into rooting hormone powder.  Fill a pot with potting soil and poke a hole in the center.  Insert at least 1 inch of the stem into the hole.  Backfill the hole gently with your fingers.  Water the pot carefully in the sink.  Place the pot in a sunny window or under grow lights.  When roots are strong, transplant them to planters filled with potting mix or outdoors. 

Nasturtiums are annual plants that self-seed easily. They are edible and attract pollinators.