Iris pseudacorus can be propagated by dividing the rhizomes or growing from seed

Rhizome division 

  1. After the blooming season, use a spade to dig up a clump of irises.
  2. Brush off some soil and separate the rhizomes into sections with healthy leaves.
  3. Trim the top half of the leaves.
  4. Dig a shallow hole in moist, rich soil.
  5. Bury the rhizomes halfway and press them into the soil.
  6. Water well and keep the soil moist.

Seed propagation 

  1. Collect the large seeds once they are ripe and the capsule has opened.
  2. Store the seeds in a cool, dry place.
  3. Sow the seeds about 1 cm deep into pots or trays of moist compost.
  4. Place the containers outdoors where they will experience winter cold.
  5. The seeds should germinate in the spring.
  6. When the seedlings are large enough, plant them in their final growing location.

Yellow Flag Wildflowers

Yellow flag iris can spread quickly and become invasive. It can out-compete native wetland plants and reduce food supplies for wildlife.