| Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'Sacramento' | Large | Dark-Green | Marginal | Yellow | Sport | Pure-White | June into July | Zilis, Mark | .2010 |
| 'Saginaw' | Small | Light-Green | - | - | Unknown | Med-Lavender | June into July | Krossa, Gus & Ruh, Peter & Ruh, Jean | .2009 .2018 |
| 'Salem' | Large | Yellow | - | - | Hybrid | Light-Purple | July | Simpers, Lucille & Ruh, Peter | .2001 |
| 'Sangamore of the Wabash' | Large | Blue/Green | Marginal | Yellow | Hybrid | - | - | Balitewicz, Bob | --NR-- |
| 'Santa Clara' | Miniature | Dark-Green | Medial | Yellow | Unknown | - | - | Malloy, Alex | --NR-- |
| 'Sapporo' | Large | Med-Green | - | - | Hybrid | Light-Purple | July into August | Klose, Heinz | --NR-- |
| 'Saratoga Sunrise' | Medium | Light-Green | - | - | Hybrid | Near-White | June into July | Dalton, Jim & Dalton, Meg | .2012 |
| 'Savannah' | Large | Med-Green | Marginal | White | Unknown | Pale-Lavender | August | Suggs, Natalee & Zilis, Mark | .1999 |
| 'Savannah Emerald' | Large | Yellow | - | - | TC Sport | Pale-Lavender | August | Zilis, Mark | .2003 |
| 'Savannah Supreme' | Large | Med-Green | Marginal | White | TC Sport | Pale-Lavender | August | Zilis, Mark | .2003 |
| 'Scioto' | Medium | Dark-Green | Streaked | White | Unknown | - | - | Love, Kenny & Wade, Van | --NR-- |
| 'Scituate Light' | Small | Med-Green | Marginal | White | Unknown | - | - | Goodenough, Rick | --NR-- |
| 'Scituate Sunrise' | Large | Yellow | - | - | Hybrid | Med-Lavender | - | Goodenough, Rick & Sanford, Matt | --NR-- |
| 'Scugog Rising Star' | Medium | Light-Green | Medial | Blue-Green | Unknown | Med-Lavender | - | Lamrock's Country Garden | --NR-- |
| 'Sea of Japan' | Large | Blue/Green | Streaked | White | Unknown | - | - | Unknown | --NR-- |
| 'Sea Richmond' | - | - | Streaked | - | Unknown | - | - | Unknown | --NR-- |
| 'Shadow Wood Ruffles' | Medium | Yellow | - | - | Unknown | - | - | Goodwin, Randy | .2013 |
| 'Shangrila' | Large | Light-Green | Marginal | Yellow | Sport | Pale-Lavender | August to September | Malloy, Alex | --NR-- |
| 'Shenandoah Abbey' | Large | Blue/Green | - | - | Hybrid | Pale-Lavender | - | Malloy, Alex | .2000 |
| 'Sherborne Profusion' | Medium | Blue/Green | - | - | Unknown | Pale-Lavender | June into July | Smith, Eric & British Hosta and Hemerocallis Society | .1988 |
| 'Sherborne Songbird' | Large | Blue/Green | - | - | Unknown | Pale-Lavender | July into August | Smith, Eric & British Hosta and Hemerocallis Society | .1988 |
| 'Sherborne Swallow' | Medium | Blue/Green | - | - | Unknown | Pale-Lavender | July | Smith, Eric & British Hosta and Hemerocallis Society | .1988 |
| 'Sherborne Swan' | Large | Blue/Green | - | - | Unknown | Near-White | July into August | Smith, Eric & British Hosta and Hemerocallis Society | .1988 |
| 'Sherborne Swift' | Medium | Blue/Green | - | - | Unknown | Near-White | July | Smith, Eric & British Hosta and Hemerocallis Society | .1988 |
| 'Sheriff of Nottingham' | Medium | Yellow | - | - | Sport | Med-Lavender | June | Zilis, Mark & Schwarz, Jim | .2012 |
| 'Sherwood Forest' | Large | Dark-Green | - | - | Hybrid | Pale-Lavender | June | Lachman, Wm & Lachman, Eleanor | .1993 |
| 'Shirofukurin Sudare Wakayama' | Small | Dark-Green | Marginal | White | Sport | - | - | Unknown | --NR-- |
| 'Silk Road' (Hansen) | Medium | Med-Green | Marginal | Yellow | Sport | Pale-Lavender | July into August | Hansen, Hans & Shady Oaks Nursery | --NR-- |
| 'Silver Bay' | Medium | Blue/Green | - | - | Hybrid | Light-Purple | July | Dean, Don | .1999 |
| 'Silver Creek Sunshine' | Medium | Med-Green | Marginal | Yellow | Hybrid | Pale-Lavender | September | Savory, Dennis | .1996 |
| 'Sioux City' | - | - | - | - | Duplicate | - | - | Duplicate Name | --NR-- |
| 'Sissy's Siberian Eyes' | Giant | Blue/Green | Streaked | White | Hybrid | Near-White | June into July | Groothuis, Mike | .2012 |
| 'Skookumchuck' | Large | Blue/Green | - | - | Unknown | Near-White | June | Duback, Robyn | .1998 |
| 'Smokey Mountains' | Medium | Blue/Green | - | - | Hybrid | Med-Lavender | August to September | Beilstein, Doug & Beilstein, Mardy | .2012 |
| 'Smuggler's Cove' | Medium | Light-Green | - | - | TC Sport | Light-Purple | July | Zilis, Mark | --NR-- |
| 'Snake Pit Falls' | - | Med-Green | - | - | Hybrid | - | August to September | Moore, Jeff | --NR-- |
| 'Snow Mountain' | Large | Med-Green | Marginal | White | TC Sport | Pale-Lavender | July | Zilis, Mark | --NR-- |
| 'Snowbird' | Small | Med-Green | Marginal | White | Unknown | - | June into July | Goodwin, Randy | .2000 |
| 'South Pacific' | Giant | Med-Green | - | - | Unknown | - | - | Ward, Dr Dick & Ward, Jane | .2009 |
| 'South Seas' | Giant | Dark-Green | Medial | Yellow | Hybrid | - | - | Sisson, Kathie | --NR-- |
| 'Spessart' | - | - | - | - | Unknown | - | - | Simon, Dr Hans | --NR-- |
| 'Spring Grove' | Giant | Med-Green | - | - | Unknown | Med-Lavender | July into August | Mack, Carl & Ruh, Peter & Ruh, Jean | .2002 |
| 'Springdale Pride' | Large | Med-Green | - | - | Unknown | - | - | Miller, Dorothy & Goodwin, Randy | .2014 |
| 'Sri Lankan Spice' | - | - | - | - | Unknown | - | - | Unknown | --NR-- |
| 'St. James Place' | Small | Med-Green | Streaked | Speckles | Hybrid | - | - | Malloy, Alex | --NR-- |
| 'Stone Horse Rocks' | - | - | - | - | Unknown | - | - | Goodenough, Rick | --NR-- |
| 'Streakin in Georgia' | Small | Light-Green | Streaked | Yellow | Unknown | Med-Lavender | - | Thaubald, Ed | --NR-- |
| 'Streakin In Nebraska' | Medium | Med-Green | Streaked | Yellow | Hybrid | Light-Purple | - | Thaubald, Ed | --NR-- |
| 'Streakin in Savannah' | Large | Dark-Green | Streaked | White | Unknown | - | - | Thaubald, Ed | --NR-- |
| 'Streakin in Syracuse' | Large | Blue/Green | Streaked | Yellow | Unknown | - | - | Thaubald, Ed | --NR-- |
| 'Suffolk Downs' | - | - | Streaked | - | Hybrid | - | - | Goodenough, Rick | --NR-- |
| 'Summer Palace' | Large | Light-Green | Marginal | Yellow | Hybrid | - | June into July | Ward, Dr Dick & Ward, Jane | .2010 |
| 'Sun Valley' | - | - | - | - | Unknown | - | - | Unknown | --NR-- |
| 'Susquehanna' | Large | Blue/Green | - | - | Unknown | - | - | Wade, Van | --NR-- |
| 'Susquehanna River' | Small | Med-Green | Marginal | White | Hybrid | - | - | Beilstein, Doug & Malloy, Alex | --NR-- |
| 'Sutter's Mill' | Large | Yellow | - | - | Hybrid | Pale-Lavender | June into July | Balitewicz, Bob | --NR-- |
| 'Swarthmore Supreme' | - | - | - | - | Duplicate | - | - | Duplicate Name | --NR-- |
| 'Sweet Home Chicago' | Medium | Yellow | Marginal | Blue-Green | TC Sport | Pale-Lavender | July | Ruh, Peter | .2002 |
| 'Sweet Home Chicago Streaked' | Medium | Dark-Green | Streaked | White | Sport | Med-Lavender | July | Miller, Jeff | --NR-- |
| 'Sycamore Creek' | Large | Dark-Green | Streaked | White | Hybrid | - | - | Moore, Jeff | --NR-- |
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