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

Family: Iridaceae (eye-rid-AY-see-ee) (Info)
Genus: Iris (EYE-ris) (Info)
Species: pseudacorus (soo-DA-ko-rus) (Info)
Cultivar: Roy Davidson
Hybridized by B. Hager
Registered or introduced: 1987
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Class:

Louisiana (LA)

Species

Height:

24-36 in. (60-90 cm)

Spacing:

12-15 in. (30-38 cm)

15-18 in. (38-45 cm)

Hardiness:

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)

Sun Exposure:

Full Sun

Danger:

Parts of plant are poisonous if ingested

Bloom Color:

Bright Yellow

Brown/Bronze

Bloom Time:

Extra early (EE)

Midseason (M)

Late Midseason (MLa)

Foliage:

Herbaceous

Other details:

May be a noxious weed or invasive

This plant is attractive to bees, butterflies and/or birds

Very high moisture needs; suitable for bogs and water gardens

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:

Unknown - Tell us

Propagation Methods:

By dividing rhizomes, tubers, corms or bulbs (including offsets)

Seed Collecting:

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed

Awards (if applicable):

Unknown - Tell us

Regional

This plant has been said to grow in the following regions:

San Leandro, California

Mathews, Virginia

Vancouver, Washington

Gardeners' Notes:

0
positives
2
neutrals
1
negative
RatingContent
Negative

On Jun 6, 2011, Jasmine6 from Mathews, VA wrote:

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 over, muscling out the cattails and other native plants. Pretty flower, but I'm sorry I ever saw it.

Neutral

On May 17, 2007, Joan from Belfield, ND (Zone 4a) wrote:

Roy Davidson is an Apogon hybrid. Holden Clough open pollinated

Neutral

On May 27, 2006, dmj1218 from west Houston, TX (Zone 9a) wrote:

Bright yellow flowers, with some veining and dark brown crescent signals, blooms on branched stems. Foliage is a lush green all summer long. Tall, vigorous grower.