Stinking iris (Iris foetidissima)
Iris foetidissima, the Stinking iris, offers persistent scarlet seeds. A shade-tolerant perennial for zones 6-9.
Complete Plant Information
Overview
Iris foetidissima, commonly known as Stinking iris or Gladwin iris, is a rhizomatous, beardless perennial valued primarily for its spectacular late-season interest rather than its lightly colored flowers. While its leaves emit an unfavorable aroma when bruised, this plant rewards patient gardeners with persistent clusters of bright orange-red seeds held in split capsules well into the winter months. This hardy species is more shade-tolerant than many of its relatives, making Iris foetidissima an excellent choice for difficult, partially shaded garden areas.
This beardless iris typically reaches 1.5 to 2 feet in height, sporting dark green, sword-shaped foliage. Pale lilac flowers appear in May, but it is the subsequent seed display that secures its place as a distinctive architectural element in the garden design. Established plants are moderately drought tolerant, though initial establishment requires consistent moisture.
Gardeners appreciate this species for its unique textural contribution and its ability to provide reliable color when many other perennials have finished blooming. Successfully integrating Iris foetidissima into the landscape brings structure and long-lasting visual appeal, especially in woodland or shaded borders.
Fast Facts
- Plant Family: Iridaceae
- Plant Type: Herbaceous perennial
- Native Range: Northern Africa, southern Europe
- Hardiness Zones: USDA Zones 6-9
- Size at Maturity:
- Height: 1-2 ft
- Spread: 1-1.5 ft
- Bloom Time: May
- Bloom Description: Pale lilac
- Sun Exposure: Full sun to part shade
- Water Needs: Medium
- Maintenance Level: Medium
How to Grow
The Stinking iris thrives when planted in moist, humusy soils that are well-drained. Aim for a location receiving full sun or part shade; notably, this Iris foetidissima species displays better shade tolerance than many other Iris types. Plant divisions in spring or fall, although spring division is often preferred in cooler climates like the St. Louis area.
While establishing, maintain medium water needs, ensuring the soil remains consistently moist. Once established, the plants tolerate periods of dryness better than when newly planted. Fertilization is rarely necessary for a healthy Iris foetidissima growing in rich soil.
If overwintering in marginal zones (like Zone 6), consider providing winter mulch and a protected location, as the foliage may not remain evergreen annually. If plants are slow to establish and begin flowering robustly, be patient; quality seed displays often take two or three years to develop fully. Division can be performed in spring or fall to manage overcrowding, and the plant can surprisingly be grown quite easily from seed.
Landscape Uses
The unique attributes of Iris foetidissima make it an excellent architectural plant, particularly in areas where sunlight is limited. It functions beautifully as an accent in woodland gardens, integrating seamlessly beneath the dappled canopy of deciduous trees. Use it to fill gaps in borders where its evergreen foliage (in warmer regions) or persistent seed heads can provide year-round interest.
This iris is highly recommended for shady locations, providing vertical structure among broader-leaved shade lovers like hostas or ferns. Due to its moderate height, it performs well near the front or middle of a mixed border, preventing it from obscuring shorter groundcovers. Its tolerance for varying light conditions means it excels in foundational plantings against buildings that receive morning sun and afternoon shade.
When planning designs, remember to site plants where their foliage will not be constantly bruised, mitigating the release of the characteristic aroma associated with the Stinking iris. The late-season coral seeds ensure that Iris foetidissima remains a focal point long after the summer bloom period concludes.
Standout Features
Flower Qualities
- Showy
Fruit Qualities
- Showy
Noteworthy Characteristics
Iris foetidissima is perhaps grown more for its attractive coral seed clusters than for its flowers, featuring rhizomatous, beardless growth reaching 1.5 to 2’ tall. Pale lilac flowers bloom in late spring, followed by capsules that split in early fall to reveal bead-like, bright orange-red seeds that persist well into winter. The dark green, sword-shaped leaves are surprisingly aromatic when cut or bruised, a characteristic reflected in its specific epithet.
Tolerances
- Deer
Potential Problems
Iris foetidissima generally suffers from no serious insect or disease problems, contributing to its moderate maintenance profile. The primary cultural concern is winter hardiness, especially near the lower limits of its recommended range (Zone 6). In areas prone to hard freezes, providing winter mulch offers protection. If the foliage is damaged by cold, it will likely rebound, though it may not remain evergreen during harsh winters.
Frequently Asked Questions
What hardiness zones is Stinking iris suitable for?
Iris foetidissima is typically suitable for USDA Zones 6 through 9.
How large does Stinking iris grow?
This perennial generally reaches a mature height of 1 to 2 feet and spreads between 1 and 1.5 feet wide.
What sun exposure does Iris foetidissima need?
Iris foetidissima prefers full sun to part shade conditions, making it adaptable to various light levels in the landscape.
When does Stinking iris bloom?
The plant typically blooms in May, producing pale lilac flowers.
Conclusion
The Stinking iris offers exceptional value primarily through its persistent, ornamental seed display, which provides vital late-season color when gardeners need it most. Integrating Iris foetidissima into your shaded perennial beds ensures architectural interest throughout the year. Before planting, confirm your local hardiness zone aligns with zones 6-9 to ensure optimal performance for this visually rewarding plant.
Propagation Tips
Division is a straightforward method for increasing your stock of Iris foetidissima. This method is best performed either in the spring or fall. Ensure that each division retains a healthy section of the rhizome and some associated leaf fans for energy reserves. As noted in its cultivation profile, this species is also noted for being surprisingly easy to grow directly from seed, offering another low-cost propagation route.
Companion Planting
Because Iris foetidissima performs well in part shade and needs medium moisture, consider pairing it with other woodland or shade-tolerant perennials. Good companions include Hellebores, which bloom earlier but offer excellent evergreen texture, and Hostas, which provide contrasting foliage shapes. Ferns also create a soft, textural backdrop that complements the sword-like leaves of the Stinking iris.
