Iris giganticaerulea Small (Giant blue iris)
Direct scans of I. giganticaerulea.
Habitat: Bayous and other wet area along the Gulf coast of Texas,
Louisiana and Mississippi.
Bloom: Late April in Zone 7/8
- Flowers: d 13-15 cm, erect standards, typical is blue
or blue purple, also lighter shades and white, rainsed mid-rib on falls
of orange or yellow
- Stem: h 95-116 cm or taller, nearly straight, 2 flowers
at apex, singles in axils
- Leaves: h to 90 cm, w 2.5 cm
- Rhizome: w 3-4 cm, bare, 20-30 cm annual growth
- Capsule/Seeds: w 3.5 cm, l 10 cm, green at maturity
/ large, corky, "D" shaped seed
- 2n = 44
- Comments: Largest of the NA natives. Very similar to
I. hexagona except larger. Has been classified as a form of
- Sun: Full sun (6 hr min.), afternoon shade if any.
- Soil type: Neutral to acid, lots of humus.
- Soil moisture: Moist to wet. Mulch to retain moisture
and protect rhizomes from sun burn.
- Feeding: Feed at onset of growth in spring and fall.
- Hardiness: Zone 7 maybe 6. Least hardly of the series.
Winter mulch above 8.
- Transplant: Easy in fall or spring after bloom.
- Seed germination: Plant seeds before they dry.
- Comments: Generally easy. Will grow in "border garden"
conditions with additional water. Needs lots of room. Grows and blooms
well for me, but doesn't reach it's potential height. I lost an unprotected
clump to a hard freeze here on the 7/8 border.
Distribution of I. giganticaerulea:
Green indicates the presence of I. giganticaerulea within the
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Last modified 11/04