| Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'Sea Biscuit' | Medium | Dark-Green | - | - | Unknown | Med-Lavender | June into July | Seaver, Mildred | --NR-- |
| 'Second Coming' | Medium | Dark-Green | Streaked | White | Nat-Sport | Pale-Lavender | August | Bennett, Gerry | --NR-- |
| 'Shade Glow' | Medium | Yellow | - | - | Unknown | - | - | Unknown | --NR-- |
| 'Shapur's Sceptre' | Medium | Med-Green | - | - | Hybrid | Light-Purple | August | Malloy, Alex | .2003 |
| 'Skyward' | Large | Blue/Green | - | - | Hybrid | Pale-Lavender | June into July | Elslager, Ed | .2000 |
| 'Squash Casserole' | Large | Yellow | Marginal | Blue-Green | Hybrid | Light-Purple | July | Avent, Tony | .1995 |
| 'Stan Kuk' | Large | Dark-Green | Marginal | Yellow | Hybrid | Near-White | June into July | Kuk, Bob | --NR-- |
| 'Stardust' | Large | Yellow | - | - | Hybrid | Pale-Lavender | July | Ward, Dr Dick & Jane | .1998 |
| 'Step Sister' | Medium | Light-Green | Marginal | Blue-Green | Nat-Sport | Near-White | June | Draheim, Gerald & Trucks, Gary | --NR-- |
| 'Summer Dress' | Large | Light-Green | - | - | Hybrid | Med-Lavender | July | Syre-Herz, Ursula | .1990 |
| 'Summer Olympics' | Large | Yellow | - | - | TC Sport | Pale-Lavender | July | Zilis, Mark | .2004 |
| 'Sunlight Sister' | Large | Light-Green | - | - | Unknown | Near-White | June | Nesmith, Elizabeth & AHS | .1986 |
| 'Swan Lake' | Large | Blue/Green | - | - | Hybrid | Pale-Lavender | August | Sugita, Hajime & Ruh, Peter | .1998 |
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