| Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'Jack and Margaret's Keynote' | Medium | Yellow | - | - | Hybrid | Med-Lavender | July into August | Owens, Clarence | .2001 |
| 'Jack Be Nimble' | Large | Blue/Green | - | - | Hybrid | - | - | Goodenough, Rick | --NR-- |
| 'Jack Blue' | Large | Blue/Green | - | - | Sport | Near-White | June | Henjum, Paul | --NR-- |
| 'Jack in the Beanstalk' | Large | Blue/Green | - | - | Unknown | - | - | Livingston, Ron | --NR-- |
| 'Jack of Diamonds' | Medium | Blue/Green | Marginal | Yellow | Hybrid | Near-White | July | Savory, Robert | .1985 |
| 'Jack's Discovery' | Medium | Med-Green | Marginal | Yellow | Sport | Med-Lavender | June into July | Freeman, Franc | .2009 |
| 'Jack's Gene' | Medium | Med-Green | - | - | Hybrid | Med-Lavender | July into August | Goodenough, Rick & Gilligan, Madelon | .2015 .2018 |
| 'Jackson's Diaper' | Small | Dark-Green | Streaked | White | Unknown | - | - | Teslow, Richard | --NR-- |
| 'Jacqueline' | - | - | - | - | Duplicate | - | - | Duplicate Name | --NR-- |
| 'Jacqueline's Banner' | Large | Med-Green | Marginal | Creamy White | Hybrid | Pale-Lavender | June into July | Jones, Gil | .1999 |
| 'Jake' | Medium | Blue/Green | - | - | Hybrid | - | - | Janssen, Bill | --NR-- |
| 'James' | Large | Yellow | - | - | Unknown | - | - | Wade, Van | --NR-- |
| 'Jami' | Medium | Yellow | - | - | Hybrid | Light-Purple | July into August | Nyikos, Frank | .2009 |
| 'Jana' | Medium | Dark-Green | Marginal | White | Unknown | - | - | Unknown | --NR-- |
| 'Jane Doe' | Large | Dark-Green | - | - | Sport | Pure-White | July into August | Nyikos, Frank | .2017 |
| 'Jane's Blush' | Medium | Blue/Green | - | - | Unknown | - | - | Solberg, Robert | --NR-- |
| 'Janet' | Medium | Light-Green | Marginal | Green | Sport | Pale-Lavender | July into August | O'Harra, Russ | .1981 |
| 'Janet Green' | Small | Dark-Green | - | - | Unknown | - | - | Unknown | --NR-- |
| 'Janet's Gold Sox' | Medium | Yellow | - | - | Sport | Med-Lavender | July | Wade, Van | --NR-- |
| 'Janet's Green Sox' | Medium | Med-Green | - | - | TC Sport | Pale-Lavender | July | Wade, Van | --NR-- |
| 'Janet's Joy' | Large | Blue/Green | - | - | Sport | Near-White | June into July | Keller, Robert | .2001 |
| 'Janet's Sister' | Medium | Yellow | Marginal | White | Sport | Pale-Lavender | July into August | Hornbaker, Rich & Hornbaker, Kathy | --NR-- |
| 'Janie Girl' | Large | Dark-Green | Medial | Yellow | Hybrid | Med-Lavender | July into August | Hanna, Clarence | .2020 |
| 'Jan's Gem' | Medium | Med-Green | - | - | Unknown | - | - | Wade, Van | --NR-- |
| 'Jason' | - | Med-Green | Streaked | White | Sport | - | August to September | Snyder, Ron | .2002 |
| 'Jason and Katie' | Large | Blue/Green | Marginal | Yellow | Sport | Pale-Lavender | June | Hatfield, Handy & Walek, Kevin | .2009 |
| 'Jay' | - | - | - | - | Unknown | - | - | Unknown | --NR-- |
| 'Jay Jay' | Giant | Blue/Green | - | - | Hybrid | Near-White | June into July | Grullemans, John J. & Ruh, Peter | .1994 |
| 'Jayka' | Medium | Med-Green | Marginal | Yellow | Sport | Pure-White | July into August | Shkundina, Marianna | .2011 |
| 'Jazzy Jane' | Medium | Med-Green | Streaked | White | Sport | Light-Purple | July | Unknown | --NR-- |
| 'Jean's Gem' | Large | Dark-Green | Streaked | Yellow | Unknown | - | - | Schmidt, Bevie | --NR-- |
| 'Jeff' | Large | Blue/Green | - | - | Unknown | Near-White | July | Wade, Van | --NR-- |
| 'Jen' | Large | Dark-Green | Marginal | Yellow | Hybrid | Pale-Lavender | July into August | Goodwin, Randy | .2000 |
| 'JenElaine' | Large | Dark-Green | Medial | Yellow | Sport | Med-Lavender | June into July | Boak, Tim | .2010 |
| 'Jennifer' | Small | Med-Green | Marginal | Yellow | Unknown | Pale-Lavender | July | Wade, Van | .2000 |
| 'Jennifer's Green Eyes' | Small | Med-Green | - | - | Sport | Pale-Lavender | July | Unknown | --NR-- |
| 'Jerry' | Large | Yellow | Marginal | Light Green | Unknown | - | - | Wade, Van | --NR-- |
| 'Jerry's Jest' | Small | Med-Green | - | - | Hybrid | - | July into August | Schulz, Ed | .2010 |
| 'Jerzy' | Medium | Dark-Green | Streaked | White | TC Sport | Med-Lavender | July into August | Unknown | --NR-- |
| 'Jessica Lynn' | Large | Med-Green | Marginal | Chartreuse | Sport | Pale-Lavender | July | Husemann, Jim | .2005 |
| 'Jessie' | Small | Med-Green | Marginal | Yellow | Unknown | - | - | Lydell, Ransom | --NR-- |
| 'Jezebel' | Small | Med-Green | Marginal | Yellow | Sport | Pale-Lavender | July into August | McHugh, Ed | .2013 |
| 'Jim and Ellie' | Large | Med-Green | - | - | Unknown | - | - | Unknown | --NR-- |
| 'Jimmy' | Small | Med-Green | - | - | Hybrid | - | - | Wade, Van | --NR-- |
| 'Jimmy Blue Eyes' | Large | Blue/Green | - | - | Unknown | - | June into July | Parsons, Phil | .2012 |
| 'Jimmy Crack Corn' | Large | Yellow | - | - | Hybrid | Near-White | June into July | Sawyer, Rick | --NR-- |
| 'Jimmy Redd' | | - | | - | Unknown | - | - | Unknown | --NR-- |
| 'Jim's Walkway' | - | - | - | - | Unknown | - | - | Unknown | --NR-- |
| 'Jo Jo' | Small | Med-Green | Marginal | White | Unknown | Light-Purple | August | Stone, David & Ruh, Peter | .1987 |
| 'Joan's Alter Ego' | Medium | Yellow-Gold | | - | Sport | Pale-Lavender | July | Bowe, Dave | .2020 |
| 'Job' | Medium | Blue/Green | - | - | Hybrid | - | June into August | Hermens, Pieter | .2012 |
| 'JoBob' | Large | Light-Green | - | - | Unknown | Med-Lavender | June into July | Gilligan, Madelon | --NR-- |
| 'Joe the Plumber' | Medium | Med-Green | Streaked | Yellow | Unknown | - | July into August | Freeman, Franc | .2012 |
| 'Johanne' | Medium | Blue/Green | - | - | Hybrid | Near-White | June into July | Ellyson, Craig & Ruh, Peter | .1989 |
| 'Johnnie Walker Red' | - | Med-Green | - | - | Unknown | - | - | Van Ostrand, John | --NR-- |
| 'Johnny Oh' | Small | Med-Green | Marginal | Yellow | Sport | Med-Lavender | July into August | Orlando, John | .2003 |
| 'Joker' | Large | Med-Green | Marginal | Yellow | Sport | Pale-Lavender | July into August | Van Vliet, Arie & Walek, Kevin | .2009 |
| 'Jolly Roger' | Giant | Blue/Green | - | - | Unknown | - | - | Serafin, Viktoria | --NR-- |
| 'Jon's Gem' | Medium | Light-Green | - | - | Unknown | - | July into August | Hatfield, Handy | .2009 |
| 'Jon's Song' | Small | Med-Green | Marginal | Yellow | Unknown | - | - | Livingston, Ron | --NR-- |
| 'Jordan's Heart' | Giant | Dark-Green | Marginal | White | Unknown | Med-Lavender | July into August | Foughty, C. & Asch, Stuart | .2011 |
| 'Joseph' | Large | Dark-Green | - | - | Sport | Light-Purple | July into August | Kuk, Bob | .1990 |
| 'Josephine' | Medium | Blue/Green | Marginal | White | Hybrid | Light-Purple | July into August | Kuk, Bob | .1987 |
| 'Joseph's Dream' | Medium | Med-Green | Medial | Yellow | Sport | Light-Purple | July into August | Unknown | --NR-- |
| 'Judi's Joy' | Medium | Med-Green | Streaked | White | Sport | Med-Lavender | July into August | Frost, Judi | .2003 |
| 'Judith' | Miniature | Light-Green | - | - | Unknown | Light-Purple | July into August | Gasparino, Judith | .2017 |
| 'Judy Blue Eyes' | Small | Blue/Green | - | - | Unknown | Med-Lavender | - | Wasitis, Chick | --NR-- |
| 'Judy's Amazing Grace' | Large | Blue/Green | - | - | Unknown | - | June into July | Treichel, Bernie | .2006 |
| 'Judy's Private Stock' | Medium | Yellow | Marginal | Green | Unknown | Med-Lavender | - | Scott, Bob | --NR-- |
| 'Judy's Surprise' | Medium | Yellow | - | - | Hybrid | Light-Purple | June into July | Walek, Kevin | .1996 |
| 'Jules' | Miniature | Med-Green | Marginal | Yellow | Sport | Pale-Lavender | July into August | Ford, Richard & Ford, Mary | .2009 |
| 'Julia' | Large | Dark-Green | Marginal | White | Sport | Pale-Lavender | July into August | White, Peter | .1984 |
| 'Julia Marie' | Small | Med-Green | Marginal | White | Unknown | - | - | Unknown | --NR-- |
| 'Julie' | Large | Blue/Green | Marginal | Yellow | Unknown | - | - | Schwarz, Jim | --NR-- |
| 'Julie Ann' | Large | Blue/Green | - | - | Unknown | Near-White | July | Bachik, Daisy & Banyai, Pauline | .1995 |
| 'Julie Marie' | Medium | Med-Green | Marginal | White | Unknown | - | - | Unknown | --NR-- |
| 'Julien and Nathalie' | Small | Light-Green | - | - | Unknown | - | - | Bastille, Jocelyne | --NR-- |
| 'Jumbo' | Giant | Blue/Green | - | - | Hybrid | Near-White | June into July | Meissner, O. & Ruh, Peter | .1997 |
| 'June' | Medium | Yellow | Marginal | Blue Green | TC Sport | Pale-Lavender | August | NEO Plants Ltd. | .1991 |
| 'June Gold' | Miniature | Yellow | - | - | Sport | - | - | Anderson, Jim | --NR-- |
| 'June's Baby' | - | Med-Green | Marginal | White | Unknown | - | July into August | Jentsch, Klaus | --NR-- |
| 'June's Beauty' | Medium | Blue/Green | Medial | Yellow | Unknown | - | - | Van den Top, Jan | --NR-- |
| 'June's Gold' | Small | Yellow | - | - | Sport | Pale-Lavender | July into August | Minks, Eldren & Ruh, Peter | .2000 |
| 'Just for Jane' | Medium | Dark-Green | Marginal | Yellow | Hybrid | - | - | Ward, Dr Dick & Ward, Jane | .2011 |
| 'Just June' | Medium | Blue/Green | Medial | Yellow | Sport | Pale-Lavender | July | Unknown | --NR-- |
| 'Justin' | Medium | Med-Green | - | - | Unknown | - | - | Malloy, Alex | --NR-- |
| 'Justine' | Medium | Light-Green | Marginal | Blue-Green | TC Sport | Pale-Lavender | July into August | Van den Top, Jan & The American Hosta Society | .2019 |
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