| Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'Ka-ching' | Giant | Dark-Green | | - | Unknown | Pale-Lavender | June into July | Zolock, Steve & Sarah | .2011 |
| 'Karamoosh' | Large | Dark-Green | Marginal | White | Hybrid | Med-Lavender | July into August | Kuk, Bob | .2008 |
| 'Kathy's Clown' | Large | Dark-Green | Medial | Yellow | Nat-Sport | Med-Lavender | July into August | Ripperger, Kathy | .2008 |
| 'Keel' | Giant | Blue/Green | | - | Hybrid | Near-White | June into August | Gilligan, Madelon | .2012 |
| 'Kelly' | Large | Blue/Green | | - | Nat-Sport | Near-White | June into July | Scolnik, Patricia & Walek, Kevin | .2009 |
| 'Kempton Run' | Medium | Med-Green | Marginal | White | Hybrid | Pale-Lavender | June into July | Ward, Dr Dick & Jane | .2011 |
| 'Kenny's Bob' | Small | Light-Green | Marginal | White | Unknown | Med-Lavender | June into July | Frederick, Ken & Peterzen, P. | .2012 |
| 'Kerfuffle' | Medium | Light-Green | Marginal | Yellow | Nat-Sport | Light-Purple | July | Zilis, Mark | .2011 |
| 'Kerry Man' | Giant | Blue/Green | | - | Nat-Sport | Near-White | June into July | Gilligan, Madelon | .2015 |
| 'Keuka Kiss' | Large | Dark-Green | | - | Hybrid | Pale-Lavender | July into August | Brandt-Sorheim, Peter & McElwee, Molly | .2002 |
| 'Key West' | Giant | Yellow | | - | Hybrid | Near-White | June into July | Petryszyn, Olga | .1999 |
| 'Kim Sue' | Medium | Med-Green | Streaked | Yellow | Unknown | Near-White | August to September | Freeman, Franc | .2009 |
| 'King Cobra' | Medium | Light-Green | | - | Hybrid | Pale-Lavender | June into July | Scheer, Alttara & Gilligan, Madelon | .2015 |
| 'King John' | Giant | Blue/Green | | - | Hybrid | - | July into August | Schwarz, Jim | .2010 |
| 'King's Lady Hyacinth' | Medium | Med-Green | Marginal | Yellow | Unknown | - | - | King, Herb | --NR-- |
| 'Kingsize' | Giant | Dark-Green | | - | Nat-Sport | Pale-Lavender | June | Van Eechaute, Danny | .2013 |
| 'Kingwood Center' | Medium | Blue/Green | Medial | Yellow | Nat-Sport | Pure-White | July | Applegate, Charles | .1993 .2018 |
| 'Kiss Me Kwick and Don't Slobber' | Large | Light-Green | | - | Hybrid | Near-White | June into July | Kwick, Charles | .2017 |
| 'Kisserina' | Small | Yellow | | - | Hybrid | Pale-Lavender | July into August | Kwick, Charles | .2017 |
| 'Klingon' | Medium | Dark-Green | | - | Nat-Sport | Pale-Lavender | June into July | Zilis, Mark & Schwarz, Jim | --NR-- |
| 'Klondike' | - | Med-Green | Streaked | Yellow | Unknown | - | - | Benedict, Dr R. (Herb) & Dorothy & Kuenster, Rod | .2010 |
| 'Koneko Falls' | Large | Yellow | Marginal | Green | Hybrid | - | - | Pether, Glen | --NR-- |
| 'Krinkled Joy' | Large | Blue/Green | | - | Hybrid | Near-White | June into July | Arett, Anne & Armstrong, Maxine & AHS | .1986 |
| 'Kristie's Key Lime Pie' | Large | Yellow | | - | Unknown | Near-White | June | Unknown | --NR-- |
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