Common name: Iris
Family: Iridaceae, Iris
Height x width: 4"-48" depending on species
Growth rate: moderate to fast
Foliage: narrow, generally linear to lanceolate, sheathing base, parallel-veined, mostly basal in fans or from bulb center
Flowers: generally 1-6 on stalks above leaves; 3 outer flower segments (falls) often drooping downwards (reflexed), sometimes with a central "beard" of colored hairs or ridge, often with a patch of different color (signal); 3 inner flower segments (standards) often upright and narrow in some species; standards and falls may be different colors, most colors available (photo courtesy Todd Weinmann, ext.nodak.edu)
Hardiness: zones 3 to 6 - 8 to 9
Soil: well-drained to wet depending on species
Light: sun
Pests and problems: bacterial soft rot and leaf spot, botrytis blight, fungal leaf spots and rusts, rhizome and crown rots, blue mold, mosaic virus, aphids, iris borer, thrips, nematodes, grubs
Landscape habit, uses: border in mass or in groups alone, some species in wet areas, cutting
Other interest: many of hybrid origin, species native to northern temperate regions; the name is for the Greek goddess Iris who supposedly walked between heaven and earth on a rainbow, and wherever she stepped on earth there arose flowers with as many colors as the rainbow (refering to the many colors available in this genus); irises have been used as emblems as early as the 6th century and by kings and countries (especially France) and provinces (such as Quebec in Canada) since; irises can be found in most styles of gardens in most countries.
Other culture: tall cultivars may need staking; divide or plants generally during dormant summer period after bloom; for bearded types with swollen rhizomes, plant with top at and parallel to soil surface; avoid heavy nitrogen fertility for best bloom; cut off diseased leaves late in season.
Propagation: divide rhizomatous types with sharp knife or spade, or pull apart such as with garden forks, usually just after bloom; cut foliage back to about 6" above crown
Species:
There are over 300 species of iris, of which the ones below are most
common. Species can be differentiated by type of roots, most being
rhizomes
but some being bulbs (danfordiae, reticulata, 'Xiphium'
hybrids).
Species can also be differentiated as bearded (Pogon iris) with the
central
stripe of hairs on the falls (Bearded hybrids, pallida),
crested
(Lophiris) with the raised central ridge on the falls (cristata,
tectorum)
and those with neither beard nor crest (Limniris) which includes most
other
species. This genus is one of the most complex and often confusing
taxonomically,
being divided into sub-genera, then into sections, sub-sections and
groups
or series with 5-25 species in each group or section, and each species
with many cultivars. Colors below are ones commonly found in the
speices,
with variation with cultivars. Soil preference is either damp (laevigata,
versicolor, virginica prefer wet) or normal being well-drained.
| Species | height | flowers | bloom | zones | soil | native |
| Bearded hybrids | 8-36" | various | summer | 3-10 | normal | various |
| chrysographes | 20-24" | dark red | summer | 4-9 | damp | Asia |
| cristata | 6-8" | lavender | spring | 3-8 | normal | U.S. |
| danfordiae | 2-4" | yellow | early spr. | 5-9 | dry | Turkey |
| ensata | 24-30" | various | summer | 4-9 | normal | Asia |
| foetidissima | 18-24" | lilac | summer | 6-9 | normal | Europe |
| laevigata | 18-24" | blue, purple | summer | 4-9 | damp | E. Asia |
| Louisana hybrids | 36-48" | various | summer | 4-9 | damp | SE U.S. |
| pallida | 24-36" | violet | summer | 4-9 | normal | N. Italy |
| prismatica | 10-12" | blue | early sum. | 4-9 | normal | E. U.S. |
| pseudacorus | 24-36" | yellow | early sum. | 4-9 | damp | Europe |
| reticulata | 2-4" | violet | early spr. | 5-8 | normal | Turkey |
| setosa | 6-36" | purple | early sum. | 4-9 | normal | NE U.S., Asia |
| sibirica | 24-36" | blue | early sum. | 3-9 | damp | Europe, Russia |
| tectorum | 12-18" | lilac | summer | 4-8 | normal | Asia |
| versicolor | 6-30" | purple | summer | 4-9 | damp | E. U.S. |
| virginica | 6-30" | blue | summer | 4-9 | damp | E. U.S. |
(Siberian iris and tall bearded photos courtesy Todd Weinmann, ext.nodak.edu; others unless noted courtesy Missouri Botanical garden plantfinder)
Cultivars:
The following are only a few representative of the most available in
the U.S. Bearded hybrids have been divided by height into Dwarf Bearded
(DB) 4-10" tall, Standard Dwarf Bearded (SDB) 10-15", Intermediate
Bearded
(IB) 15-28", and Tall Bearded (TB) over 28". Dutch iris are hybrids
generally
of xiphium and tingitana.
| Cultivars | species,group | flowers |
| 'Activity' | ensata | soft blue, purple veins |
| var. alba | cristata | white, yellow crests |
| var. alba | tectorum | white, yellow crest on falls |
| 'Angel Wings' | Dutch | white |
| 'Ann Dasch' | sibirica | violet blue, pale blue mottle |
| 'Anna Belle Babson' | TB | deep pink, tangerine beard, large |
| 'Baby Blessed' | SDB | lime yellow |
| 'Banbury Ruffles' | DB | purple |
| 'Bastardii' | pseudacorus | creamy yellow |
| 'Beverly Sills' | TB | peach, Dykes award winner |
| 'Brown Lasso' | IB | yellow gold standards, orchid falls |
| 'Butter and Sugar' | sibirica | butter yellow, white standards |
| 'Caesar's Brother' | sibirica | velvety violet |
| 'Cantab' | reticulata | pale blue, violet on falls |
| 'Carrot Curls' | SDB | orange, crinkled edges |
| 'Cherry Garden' | SDB | red purple standards, bluish beard |
| 'Claret Cup' | versicolor | burgundy red, white and yellow falls |
| 'Cry of Rejoice' | ensata | purple, yellow centers |
| 'Dancing Nanou' | sibirica | violet blue, ruffled purple falls |
| 'Dewful' | sibirica | blue, paler styles |
| 'Dover Beach' | TB | blue |
| 'Dreaming Spires' | sibirica | lavender and royal purple |
| 'Dreaming Yellow' | sibirica | white, creamy white flaring falls |
| 'Ego' | sibirica | reddish purple |
| 'Eric the Red' | sibirica | red violet |
| 'Ewen' | sibirica | violet red |
| 'Flight of Butterflies' | sibirica | blue, small |
| 'Flore-plena' | pseudacorus | yellow, double |
| 'Forrest McCord' | sibirica | velvet violet blue, gold and white blaze |
| 'Fourfold White' | sibirica | white, yellow at base of falls |
| 'Gallant Moment' | TB | bronze-red |
| 'Going My Way' | TB | purple, orange beard, ruffled |
| 'Golden Harvest' | Dutch | dark yellow |
| 'Gypsy Caravan' | TB | gold, maroon |
| 'Halcyon Seas' | sibirica | dark 3-tone blue purple |
| 'Harmony' | reticulata | royal blue, yellow and white blotched falls |
| 'Harpswell Happiness' | sibirica | creamy white |
| 'Henry's White' | ensata | white, yellow striped falls |
| 'Illini Charm' | sibirica | lilac, white, violet veins |
| 'Imperator' | Dutch | medium dark blue |
| 'Joyce' | reticulata | sky blue, white blotched falls |
| 'Joyce Terry' | TB | yellow, white, white falls |
| 'Laced Cotton' | TB | white, lacy, large |
| 'Lady Friend' | TB | garnet rose |
| 'Lady Vanessa' | sibirica | wine red, ruffled |
| 'Lavender Bounty' | sibirica | lavender falls, lighter standards, early |
| 'Lemon Mist' | TB | light yellow, ruffled, flaring falls |
| 'Limeheart' | sibirica | creamy white to light yellow |
| 'Modern Classic' | TB | white, violet veins, pale yellow beard |
| 'Mulled Wine' | TB | raspberry burgundy, lacy |
| 'Mystique' | TB | violet purple, blue beard slightly ruffled |
| 'Navy Doll' | DB | light yellow, purple splotch |
| 'Olympiad' | TB | light blue, lighter falls |
| 'Orville Fay' | sibirica | blue, darker veins |
| 'Pansy Purple' | sibirica | velvet violet |
| 'Perry's Blue' | sibirica | sky blue |
| 'Pink Bubbles' | IB | pink, deeper beard, flared, ruffled |
| 'Pink Lady' | ensata | light pink, single, large |
| 'Pippi-longstockings' | SDB | bright yellow, purple spots |
| 'Pirate Prince' |
sibirica |
bluish purple |
| 'Purple Gem' | reticulata | deep purple |
| 'Purple Sensation' | Dutch | dark violet purple, yellow marked falls |
| 'Rain Dnce' | SDB | clear blue |
| 'Ritz' | DB | yellow standards, blue tint |
| 'Royal Banner' | ensata | purple red, yellow blotch |
| 'Royal Herald' | sibirica | dark purple |
| 'Ruffled Ballet' | TB | light blue standards, darker falls, ruffled |
| 'Ruffled Velvet' | sibirica | deep velvet purple |
| 'Savoir Faire' | sibirica | cobalt violet, small yellow |
| 'Shirley Pope' | sibirica | velvet red-purple, wide, white |
| 'Silver Edge' | sibirica | purple, silver edges |
| 'Sky Wings' | sibirica | purple pink |
| 'Snow Maiden' | SDB | white, chartreuse veins |
| 'Snow Queen' | sibirica | snow white |
| 'Sparkling Rose' | sibirica | red violet |
| 'Summer Storm' | ensata | deep purple, yellow marking |
| 'Super Ego' | sibirica | light blue and lavender bicolor |
| 'Supersimmon' | TB | bright persimmon orange |
| 'Superstition' | TB | ebony black, black-blue beard, ruffled |
| 'Tarheel Elf' | SDB | deep purple |
| 'Tealwood' | sibirica | violet black, flat standards |
| 'Tycoon' | sibirica | violet blue, large, drooping falls |
| 'Variegata' | ensata | dark purple, white edged leaves |
| 'Variegata' | pseudacorus | greenish-gold leaves early and late, yellow |
| 'Vi Luihn' | sibirica | deep cobalt blue, pale yellow |
| 'Watercolor' | DB | light yellow brown spot on falls |
| 'White Swirl' | sibirica | white, yellow tint |
©Authored by Dr. Leonard Perry, Professor, University of Vermont as part of PSS123 course.
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