Growing Water Iris from Seed in a Liner Pond

Your pond iris (Iris pseudacorus or similar) is setting seed—great! Even without soil in a lined pond, you can propagate them easily.

Seed Collection & Prep

1. Allow pods to turn brown and split on the plant.
2. Collect seeds (brown/black half-moons, ~½ pea size).
3. Seeds need cold stratification (vernalization) to break dormancy.

Two Stratification Methods

Outdoor (easiest): Sow seeds in pots, leave outside all winter. They’ll germinate in spring as soil warms.

Refrigerator (controlled): Place seeds in damp paper towel, seal in baggie, refrigerate (not freeze) 60 days. In Feb, sow barely covered in pots, keep warm/moist. Germination in 2–3 weeks.

Seedling Care

• Seedlings look like grass blades—grow in nursery beds to distinguish from weeds.
• Harden off 10 days in shade after last frost, then plant in full sun at pond margins.
• Bloom usually in year 2–3.

Tip: Iris pseudacorus seeds often germinate in rock crevices around ponds naturally—mimic this with moist, gritty mix.