| No. | Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Season | Source | Registered |
|
1
| 'Katherine S. Mahoney' | Medium | Med-Green | | - | Unknown | September to October | Chamberlain, Steve | .2006 |
|
2
| 'Katsuragawa Beni' | Medium | Med-Green | | - | Unknown | August September October | Masoka, Hiroshi | --NR-- |
|
3
| 'Kelsey' | Medium | Med-Green | | - | Hybrid | August September October | Williams, Frances & Ruh, Peter | .1996 |
|
4
| 'Kifukurin Mizu' | Small | Dark-Green | Marginal | Yellow | Sport | September to October | Unknown | --NR-- |
|
5
| 'Kikeika' | Small | Dark-Green | | - | Sport | September to October | Unknown | --NR-- |
|
6
| 'Kikeika Mizu' | Small | Med-Green | | - | Sport | September to October | Unknown | --NR-- |
|
7
| 'Kinakafu' H. longissima | Small | Dark-Green | Medial | Yellow | Sport | September to October | Honda | --NR-- |
|
8
| 'King of Spades' | Medium | Dark-Green | | - | Hybrid | August September October | Beilstein, Doug & Beilstein, Mardy | .2007 |
|
9
| 'Kingfisher' | Medium | Blue/Green | | - | Unknown | August September October | Smith, Eric & British Hosta and Hemerocallis Society | .1988 |
|
10
| 'Kiss an Angel Good Morning' | Medium | Dark-Green | Marginal | Yellow | Hybrid | October | Kwick, Charles | .2018 |
|
11
| 'Kiss to Remember' | Small | Yellow-Gold | | - | Hybrid | September to October | Kwick, Charles | .2018 |
|
12
| 'Kokuryu' | Medium | Med-Green | | - | Unknown | October | Kurasawa, Tsuneo & Ruh, Peter | .2000 |
|
13
| 'Komyo Nishiki' | Small | Med-Green | Medial | White | Sport | August September October | Unknown | --NR-- |
|
14
| 'Kyoto' | Medium | Med-Green | | - | Hybrid | August September October | Sugita, Hajime & Ruh, Peter | .2001 |
|