Rain gardens are becoming more popular which is great news. This shallow depression, or even flat area filled with drainage (layers of sand, small size gravel and some permeable soil) can collect storm and rain water, hold it and slowly soaks back into the soil without causing flooding. So this area can be filled with water, but can completely dry out in drier summer periods. By installing a rain garden or using the principles of a rain garden in your landscaping, you greatly increase your contribution to preventing local flooding, water pollution, preserving clean rainwater and helping to recharge local groundwater systems. Rain gardens can be placed in urban areas, public spaces, schools, at government buildings or on private properties. Another great benefit is creating valuable habitat for small mammals, birds and insects, because the planted perennials and small shrubs are native plants (depending on the size, trees can be used too). And they look like low maintenance flower bed!
The best plants for rain garden :
1. zone = the deepest area that holds the water for the longest time (should infiltrate within 24 hours). Perennials - Asclepias incarnata (Swamp milkweed), tall asters (Aster novae-anglia, A. novi-belgii), Caltha palustris (Marsh marigold), sedges as Carex stricta (Tussock sedge), Chelone glabra (White turtlehead), Equisetum species (Horsetail), Eupatorium perfoliatum (Boneset), Helenium autumnale (Sneezeweed), Helianthus angustifolius (Swamp sunflower), Hibiscus moscheutos (Swamp rose mallow), Iris versicolor (Blue flag iris), rushes (Juncus effusus ), Lobelia (Lobelia siphlitica, Lobelia cardinalis), Mimulus ringens (Monkey flower), ferns (Onoclea sensibilis, Osmunda cinnamomea, Osmunda regalis), Panicum virgatum (Switchgrass), Scirpus atrovirens (Green bullrush), Senecio aureus (Golden ragwort), Solidago patula, Solidago rugosa (Goldenrod), Verbena hastata (Blue vervain) and others. From shrubs for example : Alnus serrulata (Smooth alder), Aronia melanocarpa (Black chokeberry), Cephalanthus occidentalis (Buttonbush), Cornus amomum (Silky dogwood), Ilex verticillata (Winterberry), Lindera benzoin (Spicebush), Physocarpus opulifolius (Ninebark), Rhododendron viscosum (Swamp azalea), Rosa palustris (Swamp rose), Sambucus canadensis (Elderberry), Viburnum cassinoides (Wild raisin), Viburnum nudum (Possumhaw).
2. zone = holds up to several incehs of water after rain, but drains much faster than zone 1. You can use most of the perennials mentioned in zone 1, or add Amsonia tabernaemontana (Blue star), Andropogon virginicus (Broomsedge), Baptisia australis (Blue false indigo), Boltonia asteroides (Boltonia), Coreopsis verticillata (Threadleaf coreopsis), Eupatorium colestinum (Mistflower), Hystrix patula (Bottlebrush grass), Physotegia virginiana (Obedient plant), Veronicastrum virginicum (Culvers root). From shrubs are suitable Chionanthus virginicus (Fringetree) or Serviceberries (Amelanchier arborea, A.canadensis or A. laevis) etc.
3. zone = transition zone between rain garden itself and surrounding landscape. This can be called the drier edge (if your rain garden has bowl shape) and it will get water infrequently and will dry the most quick. You can plant any "garden perennial", the best can be these : Agastache foeniculum (Anise hyssop), Amsonia tabernaemontana (Blue star), Asclepias tuberosa (Butterfly weed), Aster lateriflorus (Calico aster), Chrysogonum virginianum (Green and gold ), Chrysopsis mariana (Golden aster), Coreopsis verticillata (Threadleaf coreopsis), Dalea purpurea (Purple prairie clover), Echinacea purpurea (Purple coneflowflower), Liatris spicata (Blazing star), Oenothera speciosa (Evening primrose).
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