| Cultivar Name | Plant Size | Leaf Color | Variegation | Var Color | Origin | Flower Color | Season | Source | Registered |
| 'Mabel-Maria Harweg' | Medium | Dark-Green | Marginal | Yellow | Unknown | Unknown | - | Seaver, Mildred & Walek, Kevin & The American Hosta Society | .2009 |
| 'Maekawa' | Medium | Med-Green | | - | Sport | Pale-Lavender | July into August | Klehm, Roy & Walek, Kevin & The American Hosta Society | .2009 |
| 'Mama Mia' | Medium | Med-Green | Marginal | Creamy White | Unknown | Pale-Lavender | July | Benedict, Dr Ralph (Herb) & Walek, Kevin & The American Hosta Society | .2009 |
| 'Marbled White' | Large | Dark-Green | Marginal | White | Unknown | Pale-Lavender | July | Owens, Clarence & Walek, Kevin & The American Hosta Society | .2009 |
| 'Maruba Iwa' | Small | Med-Green | | - | Sport | Pale-Lavender | September | Unknown & Walek, Kevin & The American Hosta Society | .2009 .2018 |
| 'Marvelous Millie' | Medium | Blue/Green | | - | Unknown | Unknown | June into July | Seaver, Mildred & Walek, Kevin & The American Hosta Society | .2009 |
| 'Masquerade' | Small | Med-Green | Medial | White | Hybrid | Deep-Purple | June into July | Grenfell, Diana & Walek, Kevin & The American Hosta Society | .2009 .2018 |
| 'Mastodon' | Large | Blue/Green | | - | Hybrid | Near-White | June into July | Vaughn, Kevin & Walek, Kevin & The American Hosta Society | .2009 |
| 'Mayan Moon' | Medium | Blue/Green | Marginal | Yellow | Sport | Pale-Lavender | July into August | Mitchell, Bill & Walek, Kevin & The American Hosta Society | .2009 |
| 'Monitor' | Giant | Dark-Green | | - | Unknown | Unknown | July | Moldovan, Steve & Walek, Kevin & The American Hosta Society | .2009 |
| 'Moon Monster' | Large | Blue/Green | | - | Unknown | Unknown | June into July | Lachman, Wm & Lachman, Eleanor & Walek, Kevin & The American Hosta Society | .2009 |
| 'Moonstruck' | Small | Blue/Green | Medial | White | Sport | Pale-Lavender | August | Zumbar, Wm & Walek, Kevin & The American Hosta Society | .2009 |
| 'Mount Holyoke' | Medium | Med-Green | Marginal | Yellow | Hybrid | Near-White | July | Lachman, Wm & Lachman, Eleanor & Walek, Kevin & The American Hosta Society | .2009 |
| 'Mutant Ninja' | Miniature | Dark-Green | Streaked | Yellow | Sport | Deep-Purple | July | Janssen, Bill & Walek, Kevin & The American Hosta Society | .2009 |
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