Thompson's Iris
Iris × thompsonii
- Native to:
- United States
Patrick Alexander (www.flickr.com) from Las Cruces, NM
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Iridaceae
- Genus:
- Iris
- Species:
- Iris × thompsonii
- USDA Symbol:
- IRTH
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Geophyte
- Height:
- 60 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- Low
- Bloom Months:
- may,jun
- Bloom Colors:
- purple, violet, blue
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
- Butterflies & Moths:
- ★☆☆☆☆ Documented Lepidoptera association (GBIF)
Keystone Species Ranking
- Caterpillar Keystone:
- ★★☆☆☆ Butterfly & moth species supported by this genus (NWF)
Garden & Ecology Notes
- Wildlife Value:
- bees, butterflies
- Deer Resistant:
- Yes
Soil Requirements
- Notes:
- Hybrid species with limited native habitat data
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 60–90 days
- Germination Time:
- 30–180 days
- Notes:
- Iris seeds often have erratic germination and may take multiple seasons to emerge.
The above propagation data sourced from Claude AI
Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).
Source: Claude AI
ORGHPS Germination Guide: Expose to fluctuation outdoor winter temperatures including freezing for 3 months. Gradually increase light and temperature in the spring. * sow fresh or soak old seed; prechill 4 weeks or place outdoors over winter and bring indoors once germinated to avoid temperature shock; transplant at 4 leaves