Q: We want to landscape an area that remains wet for a while after each rain. Which plants would be best?
If there's nothing that you can do to alter the soggy conditions, then you need plants that don't mind the muck.
Wet soil can mean the death of many landscape plants — due not only to excess water but also to lack of oxygen. Plants that can't tolerate such conditions usually die of suffocation.
Improving drainage in the area is always a plus; consider installing a French drain, a wet-weather bed or raised beds. If none of those possibilities, choose plants that handle varying degrees of wetness.
If you have an area in your landscape that's occasionally wet but dries reasonably well in a few days, you might consider these perennials, shrubs and trees: astilbe, cardinal flower, sedge, rose mallow, summersweet, hibiscus, European cranberrybush viburnum, leucothoe, fothergilla, inkberry, sweetspire, sweet and swamp azaleas, white spruce and black gum.
For more serious water issues, these plants that can handle longer submersion.
Perennials That Can Handle Prolonged Submersion
blue flag (Iris vericolor)
bog arum(Calla palustris)
cattail (Typha spp.)
cordgrass (Spartina alterniflora)
flowering rush (Butomus umbellatus)
golden club (Orontium aquaticum)
hardy arum (Peltandra virginica)
horsetail (Equisetum hyemale)
Japanese water iris (Iris ensata)
marsh marigold (Caltha palustris)
rush (Juncus spp.)
southern blue flag (Iris virginica)
spike rush (Eleocharis acicularis)
sweet flag (Acorus calamus)
water canna (Canna x generalis)
water iris (Iris laevigata)
yellow flag (Iris pseudacorus)
Shrubs That Can Handle Prolonged Submersion
button bush (Cephalanthus occidentalis )
red osier dogwood (Cornus sericea )
tartarian dogwood ( Cornus alba)
winterberry (Ilex verticillata)
yaupon holly (Ilex vomitoria)
Trees That Can Handle Prolonged Submersion
Atlantic white cedar (Chamaecyparis thyoides)
baldcypress (Taxodium sp.)
black ash (Fraxinus nigra)
green ash (Fraxinus pennsylvanica)
pear (Pyrus spp.)
pin oak (Quercus palustris)
river birch (Betula nigra)
red maple (Acer rubrum)
swamp tupelo (Nyssa sylvatica var. biflora)
sweetbay magnolia (Magnolia virginiana)
water tupelo (Nyssa aquatica)