| Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'Temple Great' | Large | Blue/Green | - | - | Hybrid | Pale-Lavender | July | Jernigan, Bettie | .1986 |
| 'Ten Karat Gold' | Medium | Yellow | - | - | Hybrid | - | - | Zilis, Mark & Ruh, Peter & Ruh, Jean | .2008 |
| 'Tenny Up' | Large | Blue/Green | - | - | Hybrid | Near-White | August | Livingston, Ron | --NR-- |
| 'Terry witha Y' | Medium | Blue/Green | | | Nat-Sport | Pale-Lavender | July into August | Herold, Glenn | .2021 |
| 'The Gambler' | Large | Yellow | - | - | Sport | Pale-Lavender | July into August | Zilis, Mark & Schwarz, Karen | .2014 |
| 'The High Life' | Medium | Yellow | Marginal | Green | TC Sport | Pale-Lavender | July into August | Barta, Jack & Micheletti, Tom & Zilis, Mark | .2012 |
| 'The Mighty Quinn' | Large | Blue/Green | Marginal | White | Sport | - | June into July | Solberg, Robert | --NR-- |
| 'The Sun' | Large | Yellow | - | - | Unknown | Med-Lavender | July | Goodwin, Randy | .2021 |
| 'Then' | - | Dark-Green | Marginal | White | Sport | - | - | Benedict, Dr Ralph (Herb) & Kuenster, Rod | .2010 |
| 'Timber Blaze' | Medium | Yellow | - | - | Unknown | Med-Lavender | - | Hackbarth, Robert | .2015 |
| 'Timothy C. Morgan' | Medium | Blue/Green | Medial | White | Unknown | Pale-Lavender | July into August | Chamberlain, Steve | .2005 |
| 'Tinker Blue' | Miniature | Blue/Green | - | - | Unknown | - | - | Benedict, Dr Ralph (Herb) & Kuenster, Rod | .2010 |
| 'To the Point' | Medium | Med-Green | - | - | Unknown | - | July into August | Schmidt, Jon | .2015 |
| 'Tom Terrific' | Large | Yellow | - | - | Hybrid | Pale-Lavender | July into August | Solberg, Robert | .2019 |
| 'Toots' | Medium | Med-Green | - | - | Hybrid | Pale-Lavender | - | Sugita, Hajime & Ruh, Peter | .1998 |
| 'Top Brass' | Giant | Yellow | - | - | Hybrid | Med-Lavender | June into July | Gilligan, Madelon | .2013 |
| 'Top of Mount Fuji' | Large | Med-Green | - | - | TC Sport | Pale-Lavender | July | Fransen, Marco & Fransen, Joyce | --NR-- |
| 'Topsy-turvy' | Medium | Dark-Green | Streaked | White | Hybrid | Pale-Lavender | July | Elslager, Ed | .2000 |
| 'Total Justice' | Large | Med-Green | Medial | White | Sport | Pale-Lavender | July into August | Dupre, Dirk | .2014 |
| 'Totally Wacky' | Large | Med-Green | - | - | Unknown | Light-Purple | August | Schwarz, Jim | .2002 |
| 'Tough Hombre' | Medium | Blue/Green | Streaked | Green | Hybrid | Med-Lavender | June into July | Elslager, Ed | .2003 |
| 'Tracy's Emerald Cup' | Large | Dark-Green | - | - | Hybrid | Pale-Lavender | July | Heuermann, Tracy | .1997 |
| 'Transformer' | - | Dark-Green | Medial | White | Unknown | - | - | Beilstein, Doug & Beilstein, Mardy | .2009 |
| 'Tropic Sunset' | Medium | Dark-Green | Medial | Yellow | Sport | - | - | Zilis, Mark | .2012 |
| 'Tropical Dancer' | Medium | Med-Green | Marginal | White | Sport | Pale-Lavender | June into July | Van den Top, Jan & Van Eechaute, Danny | .2008 |
| 'Tropicana' | Large | Light-Green | Marginal | White | Hybrid | Pale-Lavender | July into August | Zilis, Mark | .2010 |
| 'Tuff Howard' | Medium | Dark-Green | - | - | Unknown | - | June into July | Freeman, Franc | .2010 |
| 'Twilight Shimmer' | Large | Dark-Green | | | Hybrid | Pure-White | July | Lysne, Rod | .2021 |
| 'Twist and Flip' | Small | Med-Green | Marginal | White | Unknown | Light-Purple | July | Lydell, Ransom | --NR-- |
| 'Twist of Fate' | Large | Blue/Green | - | - | Hybrid | Pale-Lavender | June into July | Walek, Kevin | .2000 |
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