Twenty plants for rock gardens in the Midwest
Agastache rupestris - threadleaf giant hyssop
Asclepias tuberosa - butterfly weed
Baptisia australis - blue false indigo
Coreopsis verticillata ‘Grandiflora’ and other cultivars
Echinacea - coneflowers
E. paradoxa - yellow coneflower
E. angustifolia - narrow-leaf coneflower
Heuchera sanguinea - coral bells
Iberis sempervirens - candytuft
Iris - standard dwarf bearded cultivars
Juniperus conferta ‘Blue Pacific’ - shore juniper
Manfreda virginica - American agave
Oenothera macrocarpa - Missouri evening primrose
Phemeranthus calycinus - fameflower
Penstemon cobaea - dew flower
Penstemon digitalis and cultivars such as ‘Husker Red’ ‘Dark Towers’ - beardtongue
Iris reticulata and cultivars
Narcissus ‘February Gold’, ‘Tete-A-Tete’ and other cultivars of miniature daffodils
Crocus vernus and cultivars - Dutch crocus
Colchicum ‘Poseidon’ and other cultivars - autumn crocus
Allium ‘Millenium’ - ornamental onion
Bouteloua gracilis - blue grama
Schizachyrium scoparium ‘The Blues’ - little bluestem
For the brave
Opuntia macrorhiza - prickly-pear
Opuntia humifusa - prickly-pear
St. Louis-area soils are predominantly clay, which can easily compact and have poor drainage. By working in a moderate amount of organic material, as well as coarse sand and pea gravel, soil drainage can be improved. Native plants that are adapted to our clay soils will perform well.
The heat and humidity of St. Louis summers is punishing. A site with afternoon shade will give plants a respite. Mulching will help to cool the soil, keep down weeds and keep moisture off leaves, an important step to reduce fungal disease caused by high heat and humidity.
Winters in St. Louis are cool to cold, with periods of mild weather. Because the ground goes through freeze and thaw cycles, newer plants with less-developed root systems can be heaved out of the ground. Plant as early as possible in fall to allow for maximum root development and mulch once the ground has cooled to add more protection.
Rain falls throughout the year, with heaviest rainfalls tending to be in the spring and summer. Some of these can be very strong thunderstorms. Snow usually falls from December to February and melts within a week or two.