| Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'I Bluit' | Medium | Blue/Green | - | - | Unknown | Pale-Lavender | July into August | Benedict, Dr Ralph (Herb) & Benedict, Dorothy & Kuenster, Rod | .2010 |
| 'Ice Age' | Medium | Dark-Green | Medial | White | Unknown | Near-White | August to September | Schmid, Tom | .2002 |
| 'Ice Cube' | Miniature | Med-Green | Marginal | White | Sport | Light-Purple | July | Fransen, Marco | --NR-- |
| 'Ichabod Crane' | Large | Med-Green | - | - | Hybrid | Pale-Lavender | June into July | Balitewicz, Bob | --NR-- |
| 'Icy Halo' | Large | Med-Green | Marginal | White | Sport | Pale-Lavender | July | Tomashek, Cindy | .2014 |
| 'Imperial Majesty' | Large | Med-Green | - | - | Hybrid | Pale-Lavender | August | Sellers, Van & Ruh, Peter | .2003 |
| 'Imperial Palace' | Large | Dark-Green | Medial | Yellow | Hybrid | Pale-Lavender | June into July | Ward, Dr Dick & Ward, Jane | .2009 |
| 'Inkwell' | Miniature | Dark-Green | - | - | Sport | Light-Purple | July | Green Mountain Hosta | --NR-- |
| 'Irish Breeze' | Medium | Med-Green | Medial | Yellow | Sport | Pale-Lavender | June | Scolnik, Patricia & Walek, Kevin | .2009 |
| 'Irish Jig' | Medium | Dark-Green | Marginal | White | Hybrid | Near-White | July into August | Ward, Dr Dick & Ward, Jane | .2012 |
| 'Irish Moss' | Medium | Med-Green | - | - | Unknown | Pale-Lavender | July | Deckert, Emile & Deckert, Jane | .2004 |
| 'Irish Ribbons' | Small | Light-Green | Marginal | White | Unknown | - | - | Kiehne, Myrtle & Anderson, Kenneth | .1992 |
| 'Iron Sky' | Small | Blue/Green | - | - | Sport | Pale-Lavender | August | Van Eechaute, Danny | .2012 |
| 'Island Flourish' | Medium | Light-Green | - | - | Hybrid | - | June into July | Blake, Amanda | .2016 |
| 'Island Splendour' | Large | Light-Green | - | - | Hybrid | - | June | Blake, Amanda | .2016 |
| 'Island Waves' | Large | Blue/Green | - | - | Hybrid | - | June | Blake, Amanda | .2016 |
| 'It's So Big' | Large | Med-Green | Streaked | Yellow | Unknown | - | - | Elslager, Ed | --NR-- |
| 'Itty Blue' | Small | Blue/Green | - | - | TC Sport | Pale-Lavender | July into August | Zilis, Mark | .2011 |
| 'Itty Gold' | Small | Yellow | - | - | Sport | - | June into July | Zilis, Mark | .2010 |
| 'Itty Rainbow' | Small | Yellow | Streaked | Green | Sport | Pale-Lavender | June into July | Zilis, Mark | .2012 |
| 'Ivory Tower' | Giant | Yellow | - | - | Hybrid | Near-White | June into July | Ward, Dr Dick & Ward, Jane | .1996 |
| 'Iwa Soules' | Large | Med-Green | - | - | Sport | Light-Purple | August to September | Soules, Marjorie & Walek, Kevin | .2009 |
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