Bright yellow flowers marked with brown-violet veining on the falls rise above upright, sword-like foliage in late spring to early summer. The bold blooms and strong vertical form bring color and structure to pond edges, rain gardens, and other persistently damp areas.
This moisture-loving perennial grows well in constantly moist soil and can tolerate shallow standing water once established. It spreads vigorously by rhizomes and seed, so grow it in a contained setting and confirm that planting is permitted in your area, as it is considered invasive in some regions.
1. Planting: Plant or repot within 4 weeks of arrival. Choose full sun to partial shade and constantly moist, rich soil. Set the rhizome just below the soil surface and consider using a submerged planting basket or sturdy container to limit spreading. Avoid planting near natural waterways.
2. Watering: Keep the soil consistently wet and do not allow it to dry out. Established plants can grow in shallow standing water, making them well suited to pond margins and boggy sites.
3. Pruning: Remove faded flowers and developing seedpods promptly to reduce self-seeding. Cut back yellow or damaged foliage in late fall. Wear gloves when handling, as the sap may irritate skin.
4. Fertilizing: Apply a light dose of balanced, slow-release fertilizer in early spring if growth is weak. Avoid overfertilizing, especially near ponds or drainage areas, to prevent nutrient runoff.