| No. | Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Season | Source | Registered |
|
1
| 'October Sky' | Medium | Blue/Green | | - | Hybrid | August to September | Dean, Don | .2008 |
|
2
| 'Ogon Iwa' | Medium | Yellow | | - | Unknown | August to September | Unknown | --NR-- |
|
3
| 'OHS Calamari' | Small | Med-Green | Medial | White | TC Sport | August to September | Lasek, Robert & Ontario Hosta Society | .2008 |
|
4
| 'Okazaki' | Small | Med-Green | | - | Hybrid | August to September | Sugita, Hajime & Ruh, Peter & Ruh, Jean | .2002 |
|
5
| 'Oshima Silk' | Medium | Med-Green | Marginal | White | Hybrid | August to September | Shimizu, Toshirou & Zilis, Mark | .2009 |
|
6
| 'Ototo San' | Miniature | Dark-Green | Marginal | White | Unknown | August to September | Ruh, Peter | .1990 .2018 |
|
7
| 'Over the Waves' | Medium | Blue/Green | | - | Unknown | August to September | Benedict, Dr Ralph (Herb) & Kuenster, Rod | .2010 |
|
8
| 'Oxford Blue Top' | Miniature | Blue/Green | | - | Unknown | August to September | Colley, June & Baker, John | .2020 |
|