| No. | Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
|
1
| 'Oberland Blue Dimension' | Medium | Blue/Green | | | Hybrid | Unknown | Unknown | Rank, Stefan | --NR-- |
|
2
| 'Ocean Isle Blue' | Medium | Blue/Green | | | Unknown | Unknown | Unknown | Chopko, Dave | --NR-- |
|
3
| 'Oceans Blue' | Large | Blue/Green | | | Unknown | Unknown | July to August | Schmidt, Bevie | .2009 |
|
4
| 'Ohh! Blue Beacon' | Small | Blue/Green | | | Unknown | Near-White | June to July | Schulz, Ed | .2013 |
|
5
| 'Ohh! Blue Bounty' | Large | Blue/Green | | | Unknown | Near-White | June to July | Schulz, Ed | .2011 |
|
6
| 'Ohh! Blue Bruiser' | Giant | Blue/Green | | | Unknown | Med-Lavender | Unknown | Schulz, Ed | .2011 |
|
7
| 'Ohh! Blue Finale' | Large | Blue/Green | | | Unknown | Pale-Lavender | June to July | Schulz, Ed | .2021 |
|
8
| 'Ohh! Blue Granite' | Medium | Blue/Green | | | Unknown | Near-White | June to July | Schulz, Ed | .2018 |
|
9
| 'Ohh! Blue Otto' | Small | Blue/Green | | | Unknown | Unknown | Unknown | Schulz, Ed | .2009 |
|
10
| 'Ohh! His Blue Eyes' | Large | Blue/Green | | | Unknown | Med-Lavender | June to July | Schulz, Ed | .2017 |
|
11
| 'Ohh! Powder River Blue' | Large | Blue/Green | | | Unknown | Near-White | June to July | Schulz, Ed | .2020 |
|
12
| 'Ohio Blue' | Unknown | Blue/Green | | | Unknown | Unknown | Unknown | Wade, Van | --NR-- |
|
13
| 'OHS Bryan's Blue' | Medium | Blue/Green | | | Hybrid | Unknown | Unknown | Ontario Hosta Society | --NR-- |
|
14
| 'Old Blue Eyes' | Medium | Blue/Green | | | Unknown | Pale-Lavender | July | Goodwin, Randy | .2021 |
|
15
| 'Old Blue Whaler' | Unknown | Blue/Green | Streaked | Unknown | Unknown | Unknown | Unknown | Goodenough, Rick | --NR-- |
|
16
| 'Ontario Blue' | Large | Blue/Green | | | Unknown | Unknown | Unknown | Wade, Van | --NR-- |
|
17
| 'Osiris Bleu Nuit' | | - | | | Duplicate | - | | Duplicate Name | |
|
18
| 'Osiris Blue Night' | Large | Blue/Green | | | Unknown | Unknown | Unknown | Fafard, Serge | --NR-- |
|
19
| 'Out of the Blue' | Giant | Blue/Green | Streaked | White | Hybrid | Pale-Lavender | July | Elslager, Ed | .2003 |
|
20
| 'Oxford Blue' | Large | Dark-Green | Medial | Yellow | Hybrid | Unknown | Unknown | Cullerton, Walter | --NR-- |
|
21
| 'Oxford Blue Top' | Miniature | Blue/Green | | | Unknown | Light-Purple | August to September | Colley, June & Baker, John | .2020 |
|