| Cultivar Name | Source | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Registered |
| 'Talcott Mountain' | Parks, David | Large | Yellow | - | - | Unknown | - | - | --NR-- |
| 'Tambourine' | Lachman, Wm & Eleanor | Medium | Med-Green | Marginal | White | Hybrid | Light-Purple | July into August | .1987 |
| 'Tarnished' | Vaughn, Kevin | Medium | Blue/Green | Streaked | Yellow | Hybrid | Pale-Lavender | July | .1987 |
| 'Tea and Crumpets' | Lachman, Wm & Eleanor | Miniature | Med-Green | Marginal | Creamy White | Hybrid | Light-Purple | July | .1996 |
| 'Tea Party' | Goodenough, Rick | Medium | Dark-Green | Marginal | Yellow | Nat-Sport | Med-Lavender | July into August | --NR-- |
| 'The Partridge Family' | Hatt, J. | Small | Med-Green | | | Nat-Sport | | | .2020 |
| 'The Shire' | Goodenough, Rick | Large | Dark-Green | - | - | Unknown | - | - | --NR-- |
| 'The Stone Horse' | Goodenough, Rick | Large | Dark-Green | Streaked | Yellow | Hybrid | - | - | --NR-- |
| 'Tijuana Brass' | Vaughn, Kevin | Medium | Yellow | - | - | Hybrid | Pale-Lavender | July | .1988 |
| 'Tijuana Taxi' | Vaughn, Kevin | Medium | Light-Green | Medial | Yellow | Nat-Sport | Pale-Lavender | July | --NR-- |
| 'Tinker Bell' | Williams, Frances & Williams, Connie | Small | Med-Green | - | - | Hybrid | Near-White | August to October | .1986 |
| 'Tiny Snowflakes' | Bemis, Royall | Miniature | - | - | - | Unknown | - | - | --NR-- |
| 'Top Banana' | Vaughn, Kevin | Medium | Med-Green | Medial | White | Hybrid | Pale-Lavender | July | .1983 |
| 'Torchlight' | Lachman, Wm & Eleanor | Large | Dark-Green | Marginal | White | Hybrid | Pale-Lavender | July into August | .1990 |
| 'Tosca's Harbor View' | Goodenough, Rick | Large | Dark-Green | Streaked | Yellow | Unknown | - | - | --NR-- |
| 'Tossed Salad' | Vaughn, Kevin & Walek, Kevin | Large | Dark-Green | - | - | Hybrid | - | July into August | .2009 |
| 'Total Eclipse' | Goodenough, Rick | Medium | Dark-Green | Medial | Green | Nat-Sport | Med-Lavender | July | --NR-- |
| 'Trifecta' | Birks, A. & Briggs Nursery-MA | Small | Med-Green | Medial | White | Nat-Sport | Pale-Lavender | June | .2008 |
| 'Trill' | Vaughn, Kevin | Large | Med-Green | - | - | Hybrid | Pale-Lavender | July | .2009 |
| 'Tutu' | Vaughn, Kevin & Walek, Kevin | Large | Blue/Green | - | - | Hybrid | Pale-Lavender | July into August | .2009 |
| 'Tuxedo' | Goodenough, Rick | Large | Dark-Green | Medial | White | Hybrid | - | June into July | .2010 |
| 'Twilight Zone' | Haskell, Allen & Malloy, Alex | Large | Med-Green | Streaked | Yellow | Nat-Sport | Pale-Lavender | - | .1999 |
| 'Twist and Shout' | Vaughn, Kevin | Large | Blue/Green | - | - | Hybrid | Light-Purple | June | .1988 |
| 'Twisted Sister' | Vaughn, Kevin | Medium | Blue/Green | - | - | Hybrid | Near-White | July | .2009 |
|