It has long bright green leaves, very tall stems and one or two musky fragrant flowers in a range of blue shades (pale, bright, dark, lavender and violet) or rarely white.

[4][5] They are shallow rooted, marked with the scars (of the previous seasons) leaves, with many branches, which can form a large clump/colony growing up to 6 x 3 feet (182 x 91 cm).

[8] It blooms from early to mid spring, in the UK and America,[3][5] with musky flowers.

[4][6][10] They have six petals, three outer sepals (called the falls), which are flaring (1.75 inch or 4 cm wide), arch downward and have a white or yellow or faint orange signal patch or ridge.

[2][4][7] They also have three inner sepals (called the standards), which are slightly erect or upright and narrower than the falls.

[5] After flowering, it has bright green ellipsoid capsules 3–4 inches (7–10 cm) long by 1 inch (3 cm) wide, which are hexagonal in cross section and shaped like a D.[5][12] As most irises are diploid, they have two sets of chromosomes.

[2][4] The Louisiana irises generally all have similar cultivation requirements, with minor differences.

[6][21][22] For best flowering, moisture is essential during late autumn, winter and spring times (between October and May), when the plant starts to grow new leaves.

The ground must be prepared pre-planting, with the addition of a generous amount of organic matter and the soils dug to about 6 inches deep (to allow for new root growth).

[8][26] Since it needs moist acid soils, with warm summers and milder winters.

[4] Iris giganticaerulea can easily hybridize with other Louisiana irises to create new variants.

Several American garden nurseries and plant breeders have created many Iris giganticaerulea cultivars including, 'Angel Wings', 'Atrocyanea', 'Barbara Elaine Taylor', 'Bayou Barataria', 'Bayou Boeuf', 'Bayou St John', 'Bette Lee', 'Billy Mac', 'Biloxi', 'Cameron White', 'China Blue', 'Citricristata', 'Citricristata Alba', 'Citriviola', 'Coteau Holmes', 'Creole Can-Can', 'Easter Surprise', 'Elephantina', 'Excitement', 'Florence Zacharie', 'Gentilly Road', 'Gheen's White', 'Giganticaerulea Alba', 'Giganticaerulea Royal', 'Gulf Mist', 'Her Highness', 'High Hat', 'Iberville', 'Isle Bonne', 'Joe Mac', 'Kildea', 'La Bahia ', 'Lafitte', 'La Premiere', 'Laughing Water', 'Lazy Day', 'Longfellow's Gabriel', 'Mandeville', 'Miraculosa', 'Paludicola', 'Ruth Holleyman', 'Silverblu ', 'Snow Flag', 'Snow Goose', 'Southern Accent','Spanish Fort', 'Trixie'.