Missouri Botanical Garden Adds a Rain Garden

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courtesy Missouri Botanical Garden/Kat Douglas
A rain garden is the newest display at the Missouri Botanical Garden in St. Louis.

One of the hottest trends in sustainable gardening practices is now part of the Missouri Botanical Garden. The new rain garden, located north of the Kemper Center for Home Gardening building, captures rain water in a garden bed, alleviating excess storm water runoff that can infiltrate the sewer system and eventually pollute lakes and streams. The garden’s ornamental display of both natives and hardy non-native cultivars was designed for easy replication by home gardeners.

Rain gardens are shallow depressions that mimic wetlands in form and function. Plants, stones and landscape characteristics force rain water to slow down and capture it temporarily. Plants and soil absorb the water, seizing impurities and carbon dioxide while releasing oxygen. When this excess water eventually reaches the sewer system, there is less contamination from chemicals and other wastes. Plants selected in the Midwest growing region should include varieties that tolerate periodic inundations followed by dry conditions later in the summer when rainfall is at a minimum.

“We chose our rain garden site because of its significant slope that naturally collected runoff,” says June Hutson, supervisor in the Kemper Center for Home Gardening. “Water would typically run to a lower drain near the site, but our new rain garden should distribute the water and eventually replace this feature.”

The Kemper Center is dedicated to home gardening, so care was taken to select plants that are easily obtained and grown. The display includes both Missouri natives and other dependable cultivars that are not native to the St. Louis-metropolitan region. The result is an ornamental display that can be both functional yet attractive to home gardeners.

Rain garden plants used by the Missouri Botanical Garden include: Achillea ‘Red Beauty,’ Amsonia ‘Blue Ice.’ Amsonia hubrichtii, Amsonia montana ‘Short Stack,’ Aster oolentaginensis, Carex ‘Ice Dance,’ Carex stricta, Coreopsis x ‘Jethro Tull,’ Echinacea purpurea ‘Vintage Wine,’ Geranium x ‘Rozanne,’ Juncus effuses, Pennisetum alopecuriodes ‘Piglet,’ Hibiscus x ‘Fantasia,’ Kalimeris ‘Blue Star,’ Lobelia syphilitica, Monarda fistulosa, Phystostegia ‘Miss Manners,’ Rudbeckia ‘City Garden,’ and Salvia nemorosa ‘Sensation Rose’.

Other selections used in edging include Asclepias tuberose, Aster laevis, Centranthus rubber, Dianthus ‘Firewitch,’ Erynguim yuccifolium, Gaura ‘Siskiyou Pink,’ Heuchera ‘Purple Petticoats,’ Heuchera ‘Rave On,’ Nepeta ‘Candy Cat,’ Oenothera macrocarpa, and Rudbeckia missouriensis.

For photographs and more about these plants, visit the Gardening Help website and search the PlantFinder database, or visit the MOBOT website.