According to city code, the seal portrays Thomas Gardner standing in front of Crystal Lake with Mount Monadnock in the distance.

Gardner is the birthplace of the Heywood-Wakefield Company, dating from 1826 when the five Heywood brothers, Walter, Levi, Seth, Benjamin, and William, began to fashion wooden chairs and furniture in a barn near their family farm.

He was soon joined by Levi and Benjamin on a part-time basis, while running a nearby country store.

In 1831, Levi moved to Boston, where he established an outlet store to sell the chairs, while Benjamin and William remained in Gardner to manufacture them.

A year later, the partnership of B. F. Heywood and Company was formed, composed of Benjamin, Walter, and William, as well as Moses Wood and James Gates.

It was invented in 1894 by Edward G. Watkins, while he was an engineer at Heywood-Wakefield when he was asked to make a better time clock to keep track of employees.

This purchase helped propel Simplex to become a leader in fire alarms and business systems.

The city is also home of the largest American Cancer Society Relay For Life event in New England.

Its highest point is the summit of Reservoir Hill, close to the city center, with an elevation of over 1,280 feet (390 m) above sea level.

[10] Gardner is bordered by Winchendon and Ashburnham to the north, Westminster to the east, Hubbardston to the south, and Templeton to the west, all in Massachusetts.

[19] Public transportation for Gardner is largely supplied by the Montachusett Regional Transit Authority (MART).

[20] Beginning in 1871, the Boston, Barre and Gardner Railroad provided rail service to the town.

[21] MART began weekday van service from Gardner to the new Wachusett terminus of the Fitchburg line in 2016.