Iris pseudacorus can be propagated by dividing the rhizomes or growing from seed.
Rhizome division
- After the blooming season, use a spade to dig up a clump of irises.
- Brush off some soil and separate the rhizomes into sections with healthy leaves.
- Trim the top half of the leaves.
- Dig a shallow hole in moist, rich soil.
- Bury the rhizomes halfway and press them into the soil.
- Water well and keep the soil moist.
Seed propagation
- Collect the large seeds once they are ripe and the capsule has opened.
- Store the seeds in a cool, dry place.
- Sow the seeds about 1 cm deep into pots or trays of moist compost.
- Place the containers outdoors where they will experience winter cold.
- The seeds should germinate in the spring.
- 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.