The Quad City Botanical Center is a set of botanical gardens located next to the Mississippi River at 2525 4th Avenue, Rock Island, Illinois. It is open daily except major holidays; an admission fee is charged.
The center opened on June 20, 1998. Its gardens include:
- Sun Garden conservatory (6,444 square feet) - includes sweet acacia, allspice, arrowhead, bamboo, banana, bird of paradise, bromeliads, cacao, cardamom, cassava, coconut, coffee, ferns, frangipani, Arabian jasmine, lychee, orchids, palms, papaya, papyrus, pineapple, sapodilla, vanilla, and ylang-ylang, as well as a 14-foot (4.3 m) waterfall, reflecting pools with koi, and a 70-foot (21 m) skylight.
- Scott County Regional Authority Conifer Garden (established 2001) - over 40 conifers from the collection of Justin C. Harper, including cultivars such as Ginkgo biloba 'Todd's Broom', Taxus cuspidate 'Fastigiate Aurea', and Thuja standishii.
- Physically Challenged Garden (established July 2003) - planting beds at varying heights for gardeners with physical limitations.
- Scrambled Alphabet Garden - for children.
