| Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'Iceberg' | Large | Med-Green | Marginal | White | Hybrid | Pale-Lavender | July into August | Avent, Tony | .2000 |
| 'Icy Halo' | Large | Med-Green | Marginal | White | Sport | Pale-Lavender | July | Tomashek, Cindy | .2014 |
| 'Icy Waters' | Large | Blue/Green | Streaked | Yellow | Unknown | | | Unknown | --NR-- |
| 'Incoming Tide' | Medium | Med-Green | Marginal | White | Unknown | | | Lydell, Ran | --NR-- |
| 'Inland Sea' | Medium | Dark-Green | - | - | Hybrid | Light-Purple | August | Sugita, Hajime & Zilis, Mark | .1998 |
| 'Irische See' | Medium | Blue/Green | - | - | Hybrid | Pale-Lavender | July | Klose, Heinz & Ruh, Peter | .1998 |
| 'Irish Coast' | Small | - | - | - | Unknown | - | - | Zumbar, Wm | --NR-- |
| 'Irish Sea' | - | - | - | - | Duplicate | - | - | Duplicate Name | --NR-- |
| 'Island Charm' | Small | Med-Green | Medial | White | Hybrid | Light-Purple | July | Rassmussen, George & Malloy, Alex | .1997 |
| 'Island Forest Gem' | Large | Dark-Green | - | - | Unknown | Pale-Lavender | July | Carpenter, Kate & Walek, Kevin | .2009 |
| 'Island Sea' | - | - | - | - | Unknown | - | - | Unknown | --NR-- |
| 'Isle Royal' | Large | Med-Green | - | - | Hybrid | Pale-Lavender | July | Wilkins, Dr Jim | .2000 |
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