1881Michael B. Olbrich is born in Chemung, Illinois.
1905Michael Olbrich graduates from University Law School (Madison).
1916Michael Olbrich envisions a sweeping park and flower garden on land adjacent to Lake Monona.
1920At Michael Olbrich's invitation, Prairie School designer and landscape architect O.C. Simonds creates a plan for the development of the park.
1921Michael Olbrich purchases 3,500 feet of Lake Monona shoreline. On July 22, 1921, the City of Madison takes title of the land destined to become Olbrich Park.
1922The Madison Parks Foundation is formed by Michael B. Olbrich, with the assistance of Paul E. Stark of the Madison Realty Company, to aquire additional land for the park..
1929Michael Olbrich dies. The City votes to name the park in his honor.
1931The City of Madison takes over the park system designed by John Olin.
1933The first flower plantings in Olbrich Park were completed by volunteers from neighborhood organizations, the Madison Garden Club, and the East Side Business Men's Association.
1935A Master Plan for Olbrich Park outlines botanical gardens.
1952Olbrich Botanical Gardens is born! The Madison Park Commission allocates $22,688 from the Olin Trust Fund to begin construction of the "Olbrich Park Gardens." The twin fieldstone-sided shelters (in the current Sunken Garden) and a connecting retaining wall along Atwood Avenue are the first structures built;
1955Stan Hill becomes Olbrich Botanical Gardens' first horticulturist. The first garden, the Rose Mall, is completed directly behind the shelters.
1958A used greenhouse was purchased and reconstructed in the area that is now the Visitor Center.
1962The Garden Center Club (now the Olbrich Garden Club) is formed.
1965The John M. Olin Fountain is constructed in the area that is now near the Rose Garden.
1969The Garden Center Club holds the first Spring Plant Sale.
1971Madison architect Stuart Gallaher designs the Garden Center building, now called the Atrium.
1975A new Master Plan is adopted for Olbrich Botanical Gardens. The Great Lawn is created.
1978The Garden Center building (Atrium) is constructed for $380,000 with funds from the Garden Center Club, the City of Madison, and private donors.
Olbrich Botanical Gardens introduces an annual holiday flower show, now known as the Holiday Express: Flower and Model Train Show.
1979The Olbrich Botanical Society is founded to support Olbrich Botanical Gardens.
1982The Herb Garden and Rock Garden (now known as the Dry Garden) are developed.
1986Stuart Gallaher designs the current Visitor Center and conservatory.
1987Parks Department Landscape Architect Nancy Ragland becomes Olbrich's first director.
1991

The Visitor Center and Bolz Conservatory are completed with three-fourths of the $4,600,000 raised from private donations. The Growing Gifts shop and Schumacher Library opened.

The Bolz Conservatory opens to the public on November 2, 1991.
1992The Wildflower Garden (now know as the Woodland Garden) is developed and two production greenhouses are constructed.
1993A Master Plan by Ken Saiki Design, Inc. of Madison and Sasaki and Associates of Massachusetts includes renovating the Rose Mall into the current Sunken Garden, and construction of the Perennial Garden, Rose Garden, and Donor's Arbor.
1994The Wildflower Garden and renovations of the Rock Garden and pond were completed.
The Olbrich Botanical Society and the Olbrich Garden Club jointly hold the 25th Annual Spring Plant Sale to support Olbrich Botanical Gardens.
1996An 80-foot long reflecting pool was added to the Sunken Garden.
1997

The Sunken Garden renovation and Rose Garden construction are completed.

The five-acre parcel containing the Garver Feed Mill was purchased by the Olbrich Botanical Society and immediately deeded to the City of Madison for future park land use.

Construction of the Donor's Arbor (a gift from the Eugenie Mayer Bolz Family Foundation) and the Flowering Grove was finished in late spring.
The Orchid Aerie in the Bolz Conservatory is completed and opened to the public in January 1998.
1998Olbrich's first Meadow Garden is developed during the spring and fall.
1999Construction of the Perennial Garden is completed.
Olbrich Botanical Gardens introduces the Butterfly Bonanza event, now known as Blooming Butterflies.
2000A fourth Master Plan is developed by Ken Saiki Design, Inc. includes the Garver Feed Mill property and new Rose Garden.
Plans for the Thai Garden and Pavilion are developed.
2001Construction of Olbrich's Royal Thai Pavilion and Garden is completed.
The Starkweather Creek Shade Garden was created.
2002Olbrich Botanical Gardens celebrates its 50th Anniversary.
The Thai Pavilion and Garden open to the public.
Olbrich's horticulture staff office move into the renovated Garver Cottage (built in 1906).
2003The Birch Walk was developed along Starkweather Creek.
2005New Rose Garden opens (now known as the Tower Garden). The original Rose Garden is renovated into the current Event Garden.
Japanese Courtyard Garden was completed in 2005.
Olbrich Botanical Gardens wins the Award for Garden Excellence from the American Public Gardens Association.
2006Olbrich Botanical Gardens is certified as a Travel Green Wisconsin destination.
A Rain Garden (on the eastern edge of what is now the Tower Garden) is completed.
Roberta Sladky becomes Olbrich Botanical Gardens' second director.
2008Serenity Garden renovated.
2009Olbrich's first Gravel Garden is installed near the Herb Garden.
Existing turf in the Perennial Garden is replaced with a more sustainable Prairie Dropseed Meadow.
2013A Facilities Master Plan for Olbrich Botanical Gardens is developed.

2014

A new Gravel Garden by the Visitor Center entrance welcomes visitors as they enter the building.
2017The Autumn Garden (between the Tower Garden and Tram Path) and the Atwood Avenue Prairie Dropseed Meadow are Olbrich's newest gardens.
Planning and design of a new learning center and greenhouse gets underway.