| Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'Jade Lancer' | Large | Med-Green | Marginal | Yellow | Unknown | Pale-Lavender | July | Tompkins, Chet & Ruh, Peter | .2001 |
| 'James A. Garfield' | Medium | Dark-Green | | | Hybrid | Pale-Lavender | August to September to October | Sugita, Hajime & Ruh, Peter | .2003 |
| 'James Buchanan' | Small | Light-Green | | | Unknown | Pale-Lavender | June to July | Sugita, Hajime & Ruh, Peter | .2005 |
| 'James Knox Polk' | Giant | Light-Green | | | Unknown | Unknown | Unknown | Ruh, Peter & Ruh, Jean | .2010 |
| 'James Madison' | Medium | Med-Green | | | Hybrid | Light-Purple | August to September to October | Sugita, Hajime & Ruh, Peter | .2005 |
| 'James Monroe' | Medium | Yellow | | | Unknown | Pale-Lavender | June to July | Sugita, Hajime & Ruh, Peter | .2005 |
| 'Jay Jay' | Giant | Blue/Green | | | Hybrid | Near-White | June to July | Grullemans, John J. & Ruh, Peter | .1994 |
| 'Jean Ferris Ruh' | Medium | Dark-Green | Medial | Yellow | Sport | Pale-Lavender | July to August | Ruh, Peter & Ruh, Jean | .2005 |
| 'Jo Jo' | Small | Med-Green | Marginal | White | Unknown | Light-Purple | August | Stone, David & Ruh, Peter | .1987 |
| 'Johanne' | Medium | Blue/Green | | | Hybrid | Near-White | June to July | Ellyson, Craig & Ruh, Peter | .1989 |
| 'John Q. Adams' | Giant | Yellow | | | Hybrid | Pale-Lavender | July | Ruh, Peter & Ruh, Jean | .2003 |
| 'John Tyler' | Large | Blue/Green | | | Unknown | Light-Purple | July | Ruh, Peter & Zilis, Mark | .2011 |
| 'Jumbo' | Giant | Blue/Green | | | Hybrid | Near-White | June to July | Meissner, O. & Ruh, Peter | .1997 |
| 'June's Gold' | Small | Yellow | | | Sport | Pale-Lavender | July to August | Minks, Eldren & Ruh, Peter | .2000 |
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