Yellow Flag Iris
Iris pseudacorus
Not currently listed at our partner nurseries.
Essentials
At a Glance
Plant Type
Perennial
Height
48 inches
Width
24 inches
Light
Full Sun, Partial Sun
Zones
4, 5, 6, 7, 8, 9
Water
Requires consistently moist soil
Humidity
Prefers moderate to high humidity
Lifespan
Perennial
Native To
Europe, North Africa, West Asia
Toxicity
All parts are toxic if ingested
The Story
Plant Bio
Iris pseudacorus is a vigorous, spreading, beardless iris that thrives in wet, boggy conditions. It is considered highly invasive in many parts of North America. Features bright yellow flowers in late spring and sword-like, gray-green leaves. Its ability to grow in standing water makes it suitable for water margins and bog gardens, but its invasive nature requires careful consideration.
Bloom Period:
Uses & Benefits:
Marketplace
Where to Buy
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Planting
How to Grow
- Tuck rhizomes into moist, well-draining soil in spring.
- Mist cuttings with water weekly to encourage rooting.
- Plant in full sun for optimal growth.
- Water regularly to keep soil moist but not waterlogged.
- Fertilize with a balanced fertilizer in early spring.
- Divide clumps every 3-4 years to maintain vigor.
Pro Tip
Plant near water for best growth and vibrant blooms.
Keep It Thriving
Care Guide
Do
- Provide consistent moisture 🌱
- Ensure full sun exposure
- Divide every few years to prevent overcrowding
Don't
- Avoid waterlogging soil ❌
- Don’t neglect pruning dead leaves
- Skip fertilizing in late fall
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Deadhead | ||||||||||||
| Divide | ||||||||||||
| Plant | ||||||||||||
| 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
Yellow Flag Iris questions
What zones can Yellow Flag Iris grow in?
Yellow 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 Yellow Flag Iris deer resistant?
Yes — Yellow Flag Iris is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Yellow Flag Iris bloom?
Yellow 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 Yellow Flag Iris need full sun?
Yellow Flag Iris does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
More Iris to compare
German Iris Bearded Iris
Iris germanica 'Mix'
Celebration Song Iris
Iris tenuissima 'Celebration Song'
Siberian Iris 'Paprikash'
Iris x hybrida 'Paprikash'
Poem of Ecstasy German Iris
Iris x germanica 'Poem Of Ecstasy'
Dutch Iris Mix
Iris hollandica 'Mix'
Baboon Bottom Bearded Iris
Iris germanica 'Baboon Bottom Bearded'
Keep exploring
Explore the genus
Collections featuring this plant
Grow Yellow 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.
