| Medium Size Hostas | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'Ain't Misbehavin' | Med-Green | | - | Hybrid | Med-Lavender | August to October | Dalton, Jim & Meg | .2012 |
| 'Don't Taz Me Bro' | Med-Green | Streaked | White | Hybrid | - | August to September | Freeman, Franc & Sally | .2010 |
| 'T N T' | Dark-Green | Medial | Yellow | Nat-Sport | Pale-Lavender | July into August | Zilis, Mark | .2010 |
| 'Table Six' | Blue/Green | Marginal | White | Nat-Sport | Pale-Lavender | July into August | Grande, Denis | .2003 |
| 'Taffeta' | Dark-Green | | - | Hybrid | Light-Purple | July | O'Harra, Russ | .1991 |
| 'Taikan' | Dark-Green | Marginal | White | Hybrid | - | - | Unknown | --NR-- |
| 'Taiwan' | Yellow | | - | Unknown | - | - | Syre-Herz, Ursula | --NR-- |
| 'Take Me Home' | Med-Green | Streaked | Yellow | Hybrid | - | - | Hawes, James | --NR-- |
| 'Tall Twister' | Med-Green | | - | Unknown | Light-Purple | August | Minks, Eldren | .1973 |
| 'Tambourine' | Med-Green | Marginal | White | Hybrid | Light-Purple | July into August | Lachman, Wm & Eleanor | .1987 |
| 'Tanayama Nishiki' | Med-Green | Marginal | Yellow | Unknown | - | - | Watanabe, Kenji | --NR-- |
| 'Tanayamanishi' | Dark-Green | Marginal | White | Nat-Sport | Light-Purple | August to September | Unknown | --NR-- |
| 'Tanbasan Nishiki' | Dark-Green | | - | Nat-Sport | Light-Purple | August to September | Unknown | --NR-- |
| 'Tangerine' | Yellow | | - | Hybrid | Pale-Lavender | July | Elslager, Ed | .1998 |
| 'Tangerine Tango' | Blue/Green | Medial | Yellow | TC Sport | Pale-Lavender | July into August | Sebright Gardens | .2013 |
| 'Tango' | Dark-Green | Marginal | Yellow | Nat-Sport | Pure-White | July | Heemskerk, Gerardus | .2005 |
| 'Tappen Zee' | Dark-Green | Marginal | White | Nat-Sport | Pale-Lavender | June into July | Malloy, Alex | .2004 |
| 'Tardiflora Gold Streak' | Yellow | Streaked | - | Nat-Sport | Med-Lavender | September to October | Unknown | --NR-- |
| 'Tardiflora Kinakafu' | Med-Green | Medial | Yellow | Nat-Sport | Med-Lavender | August to October | Unknown | --NR-- |
| 'Tardiva Variegata' | Med-Green | Streaked | Yellow | Unknown | - | - | Unknown | --NR-- |
| 'Tarheel Blue' | Blue/Green | | - | Hybrid | - | - | Solberg, Robert | .2013 |
| 'Tarnished' | Blue/Green | Streaked | Yellow | Hybrid | Pale-Lavender | July | Vaughn, Kevin | .1987 |
| 'Tasce' | Blue/Green | | - | Unknown | - | - | Wade, Van | --NR-- |
| 'Tässchen' | Blue/Green | | - | Hybrid | Near-White | - | Maindok, Hans-Hennig | --NR-- |
| 'Taunton' | Light-Green | | - | Hybrid | Near-White | June into July | Gilligan, Madelon | .2017 |
| 'Tea Biscuit' | Light-Green | | - | Unknown | Pure-White | July | Lydell, Ransom | --NR-- |
| 'Tea Party' | Dark-Green | Marginal | Yellow | Nat-Sport | Med-Lavender | July into August | Goodenough, Rick | --NR-- |
| 'Teacher's Pet' | Blue/Green | Marginal | White | Hybrid | Near-White | June into July | Asch, Stuart | .2000 |
| 'Teacher's Pride' | Blue/Green | Medial | White | Nat-Sport | Med-Lavender | July | Fransen, Marco & Joyce & van Rossum, Jannes | --NR-- |
| 'Tear Drop Of The Sun' | Yellow | | - | Unknown | - | - | Unknown | --NR-- |
| 'Teatime' | Blue/Green | Marginal | Yellow | Nat-Sport | Pale-Lavender | July into August | Zilis, Mark | .2006 |
| 'Telly's Treasure' | Dark-Green | Streaked | Yellow | Unknown | - | July into August | Singer, Mary & Elslager, Ed | .2002 |
| 'Templar Gold' | Yellow | | - | Unknown | Med-Lavender | July | Deckert, Emile & Jane | .2004 |
| 'Temple of Karnak' | Dark-Green | | - | Unknown | Near-White | July | Van Ostrand, John | --NR-- |
| 'Ten Karat Gold' | Yellow | | - | Hybrid | - | - | Zilis, Mark & Ruh, Peter & Jean | .2008 |
| 'Tennessee Waltz' | Med-Green | | - | TC Sport | Med-Lavender | August | Zilis, Mark | --NR-- |
| 'Tenryo' | Blue/Green | | - | Unknown | - | - | Unknown | --NR-- |
| 'Tentacles' | Med-Green | | - | Hybrid | Pale-Lavender | August | Seaver, Charles | .1996 |
| 'Tequila Sunrise' | Yellow | | - | Hybrid | - | - | Johnson, Greg | .2004 |
| 'Terpsichore' | Med-Green | | - | Hybrid | Light-Purple | July | Scheer, Alttara | --NR-- |
| 'Terry' | Dark-Green | Marginal | Creamy White | Nat-Sport | Pale-Lavender | July | Owens, Clarence | .2002 |
| 'Terry Wogan' | Blue/Green | | - | Nat-Sport | Pale-Lavender | August | Ford, Richard & Mary | .2006 |
| 'Tetra' | Dark-Green | | - | Hybrid | - | - | Klose, Heinz | --NR-- |
| 'The Big Easy' | Dark-Green | Marginal | Green | TC Sport | - | July into August | Zilis, Mark | .2009 |
| 'The British Are Coming' | Blue/Green | | - | Nat-Sport | - | - | Silvers, Bill | --NR-- |
| 'The Devil’s Edge' | Dark-Green | Marginal | Green | TC Sport | - | July into August | Zilis, Mark | .2009 |
| 'The Enforcer' | Blue/Green | Streaked | White | Unknown | - | August | Schwarz, Jim | .2009 |
| 'The High Life' | Yellow | Marginal | Green | TC Sport | Pale-Lavender | July into August | Barta, Jack & Micheletti,Tom & Zilis, Mark | .2012 |
| 'The Perfect Storm' | Med-Green | Streaked | White | Hybrid | Near-White | August | Wrede, Arthur | .2005 |
| 'The Queen' | Yellow | Marginal | Blue-Green | Nat-Sport | Pale-Lavender | July | Schwarz, Jim | .2007 |
| 'The Right One' | Blue/Green | Medial | Yellow | Hybrid | Med-Lavender | July | Elslager, Ed | --NR-- |
| 'The Sequel' | Med-Green | Marginal | Yellow | Unknown | - | - | Avent, Tony | --NR-- |
| 'The Sleeper' | Med-Green | | - | Hybrid | Med-Lavender | June into July | Gilligan, Madelon | .2017 |
| 'The Sweetest Thing' | Med-Green | Streaked | White | Hybrid | Med-Lavender | - | Hanson, Curt & Fransen, Marco | --NR-- |
| 'The Twister' | Med-Green | | - | Unknown | Light-Purple | August | Savory, Robert & AHS | .1986 |
| 'The Wind Blew' | Blue/Green | | - | Unknown | Pale-Lavender | July into August | Benedict, Dr R. (Herb) & Kuenster, Rod | .2010 |
| 'Thea' | Med-Green | Streaked | White | Nat-Sport | Pale-Lavender | July into August | Stratham, Netta & Bond, Sandra | .1985 |
| 'Thelonius' | Blue/Green | | - | Hybrid | Near-White | July into August | Ward, Dr Dick & Jane | .2009 |
| 'Theo’s Red' | Med-Green | | - | Hybrid | Med-Lavender | - | Leydens, Theo | --NR-- |
| 'Theo's Blue' | Blue/Green | | - | Hybrid | Med-Lavender | - | Zonneveld, Ben & Leydens, Theo | --NR-- |
| 'Thomas Hogg' | Med-Green | Marginal | White | Unknown | - | - | Bailey, Liberty Hyde & AHS | --NR-- |
| 'Thor' | Med-Green | | - | Hybrid | Pale-Lavender | August | Ruh, Peter | .1994 |
| 'Three Coins' | Med-Green | Marginal | White | Nat-Sport | Pale-Lavender | August | Jones, Leonard | .2000 |
| 'Thunder Boomer' | Blue/Green | | - | Hybrid | Pale-Lavender | July | Solberg, Robert | .2007 |
| 'Thy Kingdom Come' | Med-Green | | - | Unknown | - | June into July | Silvers, Bill | .2012 |
| 'Tidal Wave' | Blue/Green | | - | Unknown | - | - | Moldovan, Steve | --NR-- |
| 'Tiffany Tune' | Light-Green | | - | Hybrid | - | - | Lysne, Rod | --NR-- |
| 'Tiffany Twirl' | Dark-Green | | - | Unknown | - | - | Tiffany, Barbara | --NR-- |
| 'Tiger Print' | Dark-Green | Streaked | White | Nat-Sport | Pale-Lavender | August | Van Eechaute, Danny | --NR-- |
| 'Tigger' | Dark-Green | Streaked | Yellow | Hybrid | Pale-Lavender | June into July | Simmering, Ron | .2000 |
| 'Tight Squeeze' | Med-Green | Medial | White | Nat-Sport | Pale-Lavender | July into August | Soucek, John | --NR-- |
| 'Tijuana Brass' | Yellow | | - | Hybrid | Pale-Lavender | July | Vaughn, Kevin | .1988 |
| 'Tijuana Taxi' | Light-Green | Medial | Yellow | Nat-Sport | Pale-Lavender | July | Vaughn, Kevin | --NR-- |
| 'Tilt-A-Whirl' | Blue/Green | | - | Hybrid | Pale-Lavender | August to September | Solberg, Robert | .2013 |
| 'Tim and Claire' | Dark-Green | | - | Unknown | - | - | Zilis, Mark | --NR-- |
| 'Timber Blaze' | Yellow | | - | Unknown | Med-Lavender | - | Hackbarth, Robert | .2015 |
| 'Time Tunnel' | Blue/Green | Marginal | Yellow | TC Sport | Near-White | June into July | Laviana, Marc & Malloy, Alex | .2001 |
| 'Timeless Beauty' | Blue/Green | Medial | White | Nat-Sport | Med-Lavender | July into August | Heemskerk, Gerardus | .2011 |
| 'Timothy C. Morgan' | Blue/Green | Medial | White | Unknown | Pale-Lavender | July into August | Chamberlain, Steve | .2005 |
| 'Timothy J. Wright' | Yellow | | - | Unknown | Med-Lavender | - | Chamberlain, Steve | .2015 |
| 'Tiny Tim' | Med-Green | Medial | White | Nat-Sport | - | - | Summers, Alex | --NR-- |
| 'Tips Up' | Med-Green | | - | Unknown | - | - | Janssen, Bill | --NR-- |
| 'Tisch Blue' | Blue/Green | | - | Hybrid | - | - | Tisch, Roland | --NR-- |
| 'Titillation' | Dark-Green | Streaked | Yellow | Unknown | - | - | Unknown | --NR-- |
| 'To the Point' | Med-Green | | - | Unknown | - | July into August | Schmidt, Jon | .2015 |
| 'Tochiga' | Med-Green | | - | Nat-Sport | Light-Purple | August to September | Unknown | --NR-- |
| 'Token' | Med-Green | | - | Hybrid | Pale-Lavender | June into July | Wade, Van | --NR-- |
| 'Tokudama' | Blue/Green | | - | Unknown | Near-White | June into July | Unknown | --NR-- |
| 'Tokudama American Green' | Dark-Green | | - | Hybrid | - | - | Wade, Van | --NR-- |
| 'Tokudama Aureonebulosa' | Blue/Green | Streaked | Yellow | Unknown | Pure-White | - | Unknown & AHS | .1987 |
| 'Tokudama Flavocircinalis' | Blue/Green | Marginal | Creamy White | Unknown | Pale-Lavender | June into July | Maekawa, Dr Fumio | .1987 |
| 'Tokudama Flavoplanata' | Blue/Green | Medial | Yellow | Nat-Sport | Near-White | June into July | Maekawa, Dr Fumio & AHS | .1987 |
| 'Tokudama Flavoplanta' | Blue/Green | Marginal | Yellow | Nat-Sport | - | - | Maekawa, Dr Fumio | .1987 |
| 'Tokudama Kinki' | Blue/Green | | - | Unknown | - | - | Unknown | --NR-- |
| 'Tokudama Sun Splash' | Blue/Green | | - | Unknown | - | - | Unknown | --NR-- |
| 'Tokudama Tetraploid' | Blue/Green | | - | Unknown | - | - | Wayside Gardens | --NR-- |
| 'Tokudama Wayside' | Blue/Green | | - | Unknown | - | - | Wayside Gardens | --NR-- |
| 'Tokudama Zager' | Blue/Green | | - | Unknown | - | - | Zager, Herbert A. | --NR-- |
| 'Tokushima Niyagawa Sudare' | Med-Green | Streaked | White | Nat-Sport | Med-Lavender | August to September | Unknown | --NR-- |
| 'Tokyo Smog' | Med-Green | | - | Hybrid | Light-Purple | August to October | Van Eechaute, Danny | --NR-- |
| 'Tom Boy' | Yellow | | - | Unknown | - | June into July | Benedict, Dr R. (Herb) & Dorothy & Kuenster, Rod | .2010 |
| 'Tom Gannon' | Med-Green | Streaked | Yellow | Hybrid | Near-White | June into July | Zolock, Steve & Sarah | .2005 |
| 'Tomahawk' | Yellow | Marginal | Green | Nat-Sport | Pale-Lavender | July | Wade, Van | --NR-- |
| 'Tomo Yuki' | Dark-Green | Marginal | White | Nat-Sport | Near-White | July into August | Terpening, Kent | .2005 |
| 'Tomoko' | Blue/Green | | - | Unknown | Near-White | July | Klose, Heinz & Ruh, Peter | .2003 |
| 'Tom's Dream' | Med-Green | Streaked | Yellow | TC Sport | Light-Purple | July into August | Zilis, Mark | .2003 |
| 'Tonoko Tachi' | Med-Green | | - | Nat-Sport | Light-Purple | July into August | Maekawa, Dr Fumio | --NR-- |
| 'Tonto' | Med-Green | Marginal | White | Nat-Sport | Pale-Lavender | July into August | Malloy, Alex | .2002 |
| 'Too Darn Hot' | Yellow | | - | Hybrid | Near-White | July | Ward, Dr Dick & Jane | .2009 |
| 'Tootie Mae' | Blue/Green | Marginal | Yellow | Nat-Sport | Near-White | June into July | Anderson, Jim | --NR-- |
| 'Toots' | Med-Green | | - | Hybrid | Pale-Lavender | - | Sugita, Hajime & Ruh, Peter | .1998 |
| 'Top Banana' | Med-Green | Medial | White | Hybrid | Pale-Lavender | July | Vaughn, Kevin | .1983 |
| 'Top Dog' | Yellow | | - | Hybrid | - | June into July | Ward, Dr Dick & Jane | .2009 |
| 'Top of the Mornin' | Yellow | | - | Hybrid | Med-Lavender | August to September | Dean, Don | .2017 |
| 'Topaz' | Blue/Green | | - | Hybrid | Light-Purple | July into August | Johnson, Greg | .2004 |
| 'Topo Gigio' | Dark-Green | Streaked | Yellow | Hybrid | - | July into August | Beilstein, Doug & Zilis, Mark | .2009 |
| 'Topscore' | Med-Green | Medial | Yellow | Unknown | - | - | Unknown | --NR-- |
| 'Topsy-turvy' | Dark-Green | Streaked | White | Hybrid | Pale-Lavender | July | Elslager, Ed | .2000 |
| 'Torchlight Supreme' | Med-Green | Streaked | White | Nat-Sport | Med-Lavender | July into August | Schwarz, Jim | --NR-- |
| 'Torchlight Variegated' | Med-Green | Streaked | Yellow | Nat-Sport | Med-Lavender | July into August | Unknown | --NR-- |
| 'Tortilla Chip' | Yellow | | - | TC Sport | Pale-Lavender | July into August | Solberg, Robert | .2002 |
| 'Total Eclipse' | Dark-Green | Medial | Green | Nat-Sport | Med-Lavender | July | Goodenough, Rick | --NR-- |
| 'Totally Awe Sum' | Med-Green | Streaked | White | Nat-Sport | Pale-Lavender | July | Koller, Mike | .2003 |
| 'Touch of Class' | Blue/Green | Medial | Yellow | TC Sport | Pale-Lavender | July | Hansen, Hans & Shady Oaks Nursery | .1999 |
| 'Touch of Flame' | Med-Green | Medial | White | Nat-Sport | Pale-Lavender | July | Lydell, Ransom | --NR-- |
| 'Touch of Frost' | Blue/Green | | - | Nat-Sport | Pale-Lavender | July | Fransen, Marco | --NR-- |
| 'Touché' | Med-Green | Streaked | White | Nat-Sport | Pure-White | July into August | Solberg, Robert & Schwarz, Jim | .2005 |
| 'Touchstone' | Med-Green | Marginal | White | Nat-Sport | Light-Purple | July into August | Bowden, Roger | --NR-- |
| 'Tough Hombre' | Blue/Green | Streaked | Green | Hybrid | Med-Lavender | June into July | Elslager, Ed | .2003 |
| 'Tour de Pise' | Blue/Green | | - | Unknown | - | September to October | Bastille, Jocelyne | --NR-- |
| 'Tower of London' | Med-Green | Streaked | Speckles | TC Sport | Pale-Lavender | July into August | Zilis, Mark | .2009 |
| 'Toy Soldier' | Blue/Green | Marginal | Yellow | Nat-Sport | Pale-Lavender | July | Solberg, Robert | .2000 |
| 'Trade Wind' | Med-Green | Streaked | Speckles | Nat-Sport | Pale-Lavender | July into August | Kulpa, John | .1994 |
| 'Trafalgar Square' | Dark-Green | | - | Unknown | - | August | Ruh, Peter & Jean | .2005 |
| 'Trail of Tears' | Med-Green | Streaked | Yellow | Nat-Sport | Med-Lavender | July into August | Soules, Marjorie | .1999 |
| 'Transiens' | Blue/Green | | - | Unknown | - | - | Unknown | --NR-- |
| 'Travelin' Man' | Med-Green | Medial | Yellow | Unknown | - | - | Port, Linda | --NR-- |
| 'Treasure Hunt' | Med-Green | Marginal | Yellow | Nat-Sport | Pale-Lavender | July | Fransen, Marco & Joyce | --NR-- |
| 'Tremont Afterglow' | Yellow | | - | Hybrid | Pale-Lavender | July into August | Livingston, Ron | .2013 |
| 'Tremont Blue Flare' | Blue/Green | | - | Unknown | - | - | Livingston, Ron | --NR-- |
| 'Tremont Ebony Angel' | Light-Green | | - | Unknown | - | - | Livingston, Ron | --NR-- |
| 'Tremont Mirage' | Med-Green | | - | Unknown | Pure-White | - | Livingston, Ron | --NR-- |
| 'Tremont Sho Girl' | Blue/Green | | - | Unknown | - | - | Livingston, Ron | --NR-- |
| 'Tremont Spice' | Med-Green | Marginal | Yellow | Unknown | Med-Lavender | - | Livingston, Ron | --NR-- |
| 'Trilogy' | Med-Green | Medial | Blue-Green | Hybrid | Pale-Lavender | June | Gilligan, Madelon | .2018 |
| 'Triple Double' | Blue/Green | | - | Hybrid | - | - | Jolliffe, Thomas | --NR-- |
| 'Tropic Sunset' | Dark-Green | Medial | Yellow | Nat-Sport | - | - | Zilis, Mark | .2012 |
| 'Tropic Thunder' | Med-Green | Marginal | Yellow | Hybrid | - | - | Ward, Dr Dick & Jane | .2012 |
| 'Tropical Dancer' | Med-Green | Marginal | White | Nat-Sport | Pale-Lavender | June into July | van den Top, Jan & Van Eechaute, Danny | .2008 |
| 'Tropical Storm' | Yellow | Medial | Green | Nat-Sport | Near-White | July | Bergeron, Amy | .2007 |
| 'True Love' | Blue/Green | | - | Hybrid | - | - | Aden, Paul | .1979 |
| 'True North' | Light-Green | Medial | Yellow | Nat-Sport | Med-Lavender | July into August | Schwarz, Jim | --NR-- |
| 'Tsuma Tajima' | Med-Green | Streaked | Creamy White | Unknown | - | August to September | Benedict, Dr R. (Herb) & Kuenster, Rod | .2010 |
| 'Tucker Charm' | Dark-Green | | - | Hybrid | Light-Purple | August | Stephens, Ray | .1993 |
| 'Tucker Friendly' | Med-Green | | - | Hybrid | - | - | Stephens, Ray | --NR-- |
| 'Tucker Top Cat' | Dark-Green | Marginal | Green | Hybrid | Near-White | June | Stephens, Ray | .1993 |
| 'Tuff Howard' | Dark-Green | | - | Unknown | - | June into July | Freeman, Franc | .2010 |
| 'Tunisian Dream' | Blue/Green | | - | Hybrid | Near-White | July into August | Terpening, Kent | .2005 |
| 'Turnabout' | Med-Green | Marginal | White | Hybrid | Pale-Lavender | July into August | Lydell, Ransom | .2001 |
| 'Turning Point' | Med-Green | | - | Nat-Sport | Pale-Lavender | August | Lydell, Ransom | --NR-- |
| 'Twisted Lizzard' | Dark-Green | Medial | White | Unknown | - | - | Unknown | --NR-- |
| 'Twisted Sister' | Blue/Green | | - | Hybrid | Near-White | July | Vaughn, Kevin | .2009 |
| 'Twister' | Dark-Green | Medial | Yellow | Nat-Sport | Med-Lavender | July into August | van den Top, Jan | --NR-- |
| 'Twizzler' | Blue/Green | | - | Hybrid | Light-Purple | July into August | Elchuk, Kevin & Olga | .2015 |
| 'Two if by Sea' | Med-Green | Medial | White | Nat-Sport | Pale-Lavender | June into July | Silvers, Bill | .2012 .2018 |
| 'Two Ladies' | Yellow | Streaked | White | Hybrid | - | - | Balitewicz, Bob | --NR-- |
| 'Two Step' | Med-Green | Marginal | Yellow | Hybrid | Pure-White | August | Aden, Paul | .1987 |
| 'Tyche of Antioch' | Dark-Green | Marginal | Yellow | Unknown | - | - | Malloy, Alex | --NR-- |
| 'Tycoon' | Med-Green | Marginal | Yellow | Unknown | - | - | Malloy, Alex | --NR-- |
|