| Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'Dartmoor Forest' | Large | Dark-Green | - | - | Hybrid | Pale-Lavender | July into August | Eason, Alan & Ruh, Peter & Ruh, Jean | .2005 |
| 'Dauntless' | Medium | Blue/Green | - | - | Hybrid | Near-White | June into July | Ruh, Peter | .2002 |
| 'Devon Desire' | Giant | Med-Green | - | - | Unknown | Pale-Lavender | July | Bowden, Roger & Bowden, Ann & Ruh, Peter | .2010 |
| 'Devon Discovery' | Giant | Med-Green | - | - | Sport | Near-White | June into July | Goater, John & Ruh, Peter | .2005 |
| 'Devon Gold' | Small | Light-Green | - | - | Unknown | Light-Purple | July | Bowden, Roger & Ruh, Peter | .2005 |
| 'Devon Green' | Medium | Dark-Green | - | - | Sport | Pale-Lavender | July | Bowden, Roger & Ruh, Peter | .2005 |
| 'Devon Mist' | Large | Blue/Green | - | - | Hybrid | Pale-Lavender | - | Bowden, Roger & Ruh, Peter | .2005 |
| 'Devon Tor' | Giant | Med-Green | - | - | Hybrid | Light-Purple | June into July | Bowden, Roger & Ruh, Peter | .2005 |
| 'Dewline' | Large | Med-Green | Marginal | White | Unknown | Pale-Lavender | June into July | Tompkins, Chet & Ruh, Peter | .2002 |
| 'Dixieland Jazz' | Medium | Med-Green | - | - | Hybrid | Near-White | July into August | Ruh, Peter & Gilligan, Madelon | .2017 |
| 'Doctor Fu Manchu' | Medium | Dark-Green | - | - | Hybrid | Light-Purple | September | Sugita, Hajime & Ruh, Peter | .1998 |
| 'Doctor Reath' | Large | Blue/Green | Streaked | Yellow | Sport | Near-White | June into July | Reath, David & Ruh, Peter | .1997 |
| 'Donahue Piecrust' | Large | Med-Green | - | - | Hybrid | Pure-White | June into July | Donahue, Thomas & Ruh, Peter | .1999 |
| 'Doreen' | Small | Light-Green | - | - | Unknown | Light-Purple | July into August | Klose, Heinz & Ruh, Peter & Ruh, Jean | .2009 |
| 'Dorset Charm' | Medium | Blue/Green | - | - | Hybrid | Pale-Lavender | August | Smith, Eric & Ruh, Peter | .1990 |
| 'Dorset Flair' | Medium | Blue/Green | - | - | Hybrid | Light-Purple | August to October | Smith, Eric & Ruh, Peter | .1990 |
| 'Dragon's Blood' | Medium | Med-Green | - | - | Hybrid | Pale-Lavender | July into August | Sugita, Hajime & Ruh, Peter | .1998 |
| 'Dustin' | Medium | Med-Green | Marginal | White | Unknown | Pale-Lavender | July into August | Stone, David & Ruh, Peter | .1988 |
| 'Dylan's Dilly' | Small | Blue/Green | Medial | Greenish White | Sport | Med-Lavender | July into August | Purtymun, Charles & Ruh, Peter & Ruh, Jean | .2008 |
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