Mercer Botanic Gardens is a free public botanic garden and park in Harris County Precinct 4. The east side of Mercer has specialty gardens featuring colorful seasonal plants, collections of Texas Native and rare plants, gingers, daylilies, bamboos, drought-tolerant plants and more.
The west side has 3 miles of hiking trails, a picnic area with tables and pavilions by reservation, and a children's playground area. There are natural areas with a cypress swamp and a hickory bog.
Volunteers assist with conservation efforts, in the gardens, greenhouses, with educational tours and with all fund-raising special events.
In the late 1940s, Thelma and Charles Mercer purchased a beautiful 14.5 acre tract of natural land along Cypress Creek. Thelma was an avid horticulturist, and she and Charles did much of the initial selective clearing to make space for some of her favorite native trees that included dogwoods, rusty black-haw viburnum, several species of hawthorns, plus many others. Thelma also planted large camellias that are still seen throughout the central gardens. She also introduced many other plant species, such as camphor, Ginkgo, Bauhinia, Philadelphus and that naturalized and are still growing beautifully. When it came time for the Mercers to retire, they could not bear the thought of a developer bulldozing their 'paradise.' So, in 1974, they convinced Harris County to purchase their original 14.5 acre tract with the stipulation that it would grow and be maintained as an educational and horticultural facility for the public's enjoyment. After Harris County purchased the land, a group of community gardeners interested in furthering the development of Mercer as a botanical facility formed the nonprofit group Mercer Arboretum Advisory Committee (MAAC). In 2000, the organization changed its name to The Mercer Society and members assist Mercer Botanic Gardens in its mission by organizing and implementing activities that encourage membership support, expand community awareness, and raise funds in support of Mercers' strategic plan. Since 1984, through donations and land purchases made by Precinct 4, Mercer has grown to 325 acres.