| Cultivar Name | Source | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Registered |
| 'I Bluit' | Benedict, Dr R. (Herb) & Kuenster, Rod | Medium | Blue/Green | - | - | Unknown | Pale-Lavender | July into August | .2010 |
| 'Ice Age' | Schmid, Tom | Medium | Dark-Green | Medial | White | Unknown | Near-White | August to September | .2002 |
| 'Icy Fog' | Wilson, Chris | Medium | Dark-Green | Medial | White | Nat-Sport | Med-Lavender | June into July | --NR-- |
| 'Iggie' | Benedict, Dr Ralph (Herb) | Medium | Yellow | - | - | Unknown | Pale-Lavender | July | --NR-- |
| 'I'm My Kid's Mom' | Elslager, Ed | Medium | Med-Green | Streaked | White | Hybrid | Pale-Lavender | July into August | .2003 |
| 'Imperial Potentate' | Benedict, Dr Ralph (Herb) & Dorothy | Large | Med-Green | Streaked | Speckles | Nat-Sport | Pale-Lavender | July into August | .1999 |
| 'Incognito' | Struhar, Bill | Large | Blue/Green | Marginal | Yellow | Nat-Sport | Near-White | July into August | .2006 |
| 'Incredible' | Benedict, Dr Ralph (Herb) | Giant | Blue/Green | Marginal | Chartreuse | Unknown | Near-White | June into July | --NR-- |
| 'Incredible Hulk' | Elslager, Ed | Giant | Dark-Green | - | - | Unknown | Pale-Lavender | July | .1998 |
| 'Incredible Hunk' | Elslager, Ed | Giant | Blue/Green | - | - | Unknown | Pale-Lavender | July | .1998 |
| 'Independence' | Westendorp, Jeff & Walters Gardens | Medium | Dark-Green | Marginal | White | Nat-Sport | Pale-Lavender | August | .2001 |
| 'Indian Feather' | Owens, Clarence | Small | Med-Green | Medial | White | Hybrid | Pale-Lavender | July | .1992 |
| 'Inky Dinky' | Trucks, Gary | Medium | Light-Green | - | - | Nat-Sport | Light-Purple | July | --NR-- |
| 'Inocquous' | Livingston, Ron | Medium | Med-Green | Marginal | Yellow | Unknown | - | - | --NR-- |
| 'Iron Curtain' | Asch, Stuart | Medium | Blue/Green | - | - | Hybrid | Near-White | June into July | .2000 |
| 'Island Breeze' | Diaz, Ariel & Hansen, Hans & Walters Gardens | Medium | Med-Green | Medial | Yellow | TC Sport | Med-Lavender | July into August | .2014 |
| 'Isle Royal' | Wilkins, Dr Jim | Large | Med-Green | - | - | Hybrid | Pale-Lavender | July | .2000 |
| 'Iszat U Doc' | Benedict, Dr R. (Herb) & Walek, Kevin | Medium | Med-Green | - | - | Hybrid | Light-Purple | July into August | .2009 |
| 'Iszat U Emmerson' | Benedict, Dr Ralph (Herb) | Small | Med-Green | - | - | Unknown | - | - | --NR-- |
| 'It Rocks' | Elslager, Ed | Large | Dark-Green | Marginal | White | Hybrid | Med-Lavender | June into July | .2004 |
| 'It's So Big' | Elslager, Ed | Large | Med-Green | Streaked | Yellow | Unknown | - | - | --NR-- |
| 'Iva Delight' | Lisik, Philip | Medium | Med-Green | Medial | White | Nat-Sport | Pale-Lavender | July into August | .2003 |
| 'Ivory Queen' | Walters Gardens | Medium | Blue/Green | Medial | White | Nat-Sport | Med-Lavender | August to September | .2014 |
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