The garden site was first established as the 37-acre (150,000 m2) estate of sisters Grace and Mary Innis.

Plantings include peony, bearded iris, daylilies, and naturalized daffodils.

[1] In 1960, sisters Grace and Mary Innis purchased a 38-acre slice of land that would become Inniswood Metro Gardens.

[2] In 1961, they moved onto the property bringing with them mementos from their childhood home on Cleveland Avenue in Linden Heights.

In 1966, Grace died and Mary began the process of donating the site to the Metro Parks system as long as she could live there until her death.