Registered by Peter Ruh of Ohio in 2000, this plant is a hybrid of H. 'Fortunei Aurea'. It was originated by Ken Herrema of Michigan and was named after Allegan County, Michigan.

The cultivar is a medium size (13 inches high by 18 inches wide) hosta with misty streaked variegation and pale lavender flowers in early to late July. It has very wavy foliage.

The New Encyclopedia of Hostas by Diana Grenfell (2009) states: "Careful positioning is important to achieve the best color effect. Surprisingly vigorous, a fairly rapid increaser once it is established...Central variegation is stippled and flecked olive green to dark green."

An article about H. 'Allegan Fog' by Warren I. Pollock in The Hosta Journal (2002 Vol. 33 No. 2) states that, "This hosta is an introduction of Ken Herrema of Englerth Nursery in Hopkins, Michigan. 'Allegan Fog' is named after Allegan County where this nursery is located. Other hostas from this nursery, started by the late Larry Englerth, also have Allegan in their names. In 2000, Peter Ruh...registered three hostas for Ken Herrema: 'Allegan Fog', 'Allegan Emperor' and 'Allegan Gent'."