Yellow Flag Iris, Yellow Iris, Water Flag Iris 'Roy Davidson'

Irispseudacorus

Family
Iridaceae (eye-rid-AY-see-ee)
Genus
Iris (EYE-ris)
Species
pseudacorus (soo-DA-ko-rus)
Synonym
Spacing
24-36 in. (60-90 cm)
Hardiness
12-15 in. (30-38 cm)
15-18 in. (38-45 cm)
Sun Exposure
USDA Zone 4a: to -34.4 °C (-30 °F)
USDA Zone 4b: to -31.6 °C (-25 °F)
USDA Zone 5a: to -28.8 °C (-20 °F)
USDA Zone 5b: to -26.1 °C (-15 °F)
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
USDA Zone 9a: to -6.6 °C (20 °F)
USDA Zone 9b: to -3.8 °C (25 °F)
USDA Zone 10a: to -1.1 °C (30 °F)
USDA Zone 10b: to 1.7 °C (35 °F)
Danger
Full Sun
Bloom Color
Parts of plant are poisonous if ingested
Foliage
Bright Yellow
Brown/Bronze
Class
N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed
Bloom Time
Other Details
Other details
Propagation Methods
Herbaceous
Seed Collecting
May be a noxious weed or invasive
Soil pH requirements
By dividing rhizomes, tubers, corms or bulbs (including offsets)
Patent Information
Awards (if applicable)
Foliage Color
Bloom Characteristics
Water Requirements
Where to Grow
Regional

This plant is said to grow outdoors in the following regions:

San Leandro, California

Sebastopol, California

Mathews, Virginia

Vancouver, Washington

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Gardener's Notes:

1
positive
2
neutrals
1
negative
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T
Sebastopol, CA | September 2015 | positive

This iris is also drought tolerant! When I planted it, I thought it more closely related to spuria iris and put it in a full sun spot wit...Read More

J
Mathews, VA | June 2011 | negative

Just don't plant this where it can get away from you!! I planted a couple near my marsh in Virginia, and it has almost completely taken o...Read More

J
J
Belfield, ND (Zone 4a) | May 2007 | neutral

Roy Davidson is an Apogon hybrid. Holden Clough open pollinated

D
west Houston, TX (Zone 9a) | May 2006 | neutral

Bright yellow flowers, with some veining and dark brown crescent signals, blooms on branched stems. Foliage is a lush green all summer lo...Read More

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