Blue Flag Iris
Iris versicolor
Essentials
At a Glance
Plant Type
Perennial
Height
24 inches
Width
18 inches
Light
Full Sun, Partial Sun
Zones
4, 5, 6, 7, 8, 9
Water
Moist to wet soils
Humidity
Moderate
Lifespan
Perennial
Native To
North America
Toxicity
All parts are toxic if ingested
The Story
Plant Bio
Iris versicolor, commonly known as Blue Flag Iris, is a perennial herbaceous plant featuring slender, sword-like leaves and striking showy blue to purple flowers with intricate markings, typically blooming in late spring to early summer. This species is noted for its tolerance of wet soils, making it an excellent choice for rain gardens, pond margins, and other moist areas. The intricate violet-blue flowers have distinctive yellow and white markings.
Bloom Period:
Uses & Benefits:
Marketplace
Where to Buy
Shipping costs Year-round shipping Free shipping
Planting
How to Grow
- Tuck rhizomes 2 inches deep in well-draining soil
- Water regularly during first growing season
- Plant in full sun for best blooms
- Mulch to retain moisture and suppress weeds
- Divide every 3-4 years in early spring or fall
- Fertilize with a balanced fertilizer in early spring
Pro Tip
Ensure good drainage to prevent root rot, especially in wet soils.
Keep It Thriving
Care Guide
Do
- Water during dry spells 🌱
- Divide in early spring or fall
- Remove spent flowers to encourage rebloom
- Mulch to conserve moisture
Don't
- Avoid overwatering in winter ❌
- Do not plant in heavy clay soil without amendment ❌
- Refrain from using high nitrogen fertilizer which encourages lush foliage over flowers ❌
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Deadhead | ||||||||||||
| Divide | ||||||||||||
| Plant | ||||||||||||
| Prune | ||||||||||||
| Spring Cleanup |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
Blue Flag Iris questions
What zones can Blue Flag Iris grow in?
Blue Flag Iris is hardy in USDA Zones 4–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Blue Flag Iris deer resistant?
Yes — Blue Flag Iris is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Blue Flag Iris bloom?
Blue Flag Iris typically blooms in late spring through early summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Blue Flag Iris need full sun?
Blue Flag Iris does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
More Iris to compare
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Iris germanica 'Mix'
Celebration Song Iris
Iris tenuissima 'Celebration Song'
Dutch Iris Mix
Iris hollandica 'Mix'
Siberian Iris 'Paprikash'
Iris x hybrida 'Paprikash'
Poem of Ecstasy German Iris
Iris x germanica 'Poem Of Ecstasy'
Baboon Bottom Bearded Iris
Iris germanica 'Baboon Bottom Bearded'
Keep exploring
Explore the genus
Collections featuring this plant
Grow Blue Flag Iris with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.
