Sunday, August 26, 2012

Rain gardens, wet spots and the native plants that love ‘em

Unique environments need plants that are adapted to deal with those environments. Consistently wet and periodically flooded areas challenge gardeners all over the world. Luckily nature created plants that work very well in such environments. Georgia has native plants – perennials, shrubs and trees – that are just waiting to live in your wet spots.

Buttonbush (Cephalanthus occidentalis)

Do you have a wet spot in your yard? I wish I did. There are so many great plants that thrive with “wet feet”. The one moderately moist spot that I have is crammed full of plants. Whenever I get something that likes it “moist”, I stick it in that spot. The cardinal flower (Lobelia cardinalis) is there. The Carolina spiderlily (Hymenocallis caroliniana) blooms every year there. Yellowroot (Xanthorhiza simplicissima) thrives nearby and I dig up some for the plant sale every year from there. Steeplebush (Spiraea tomentosa) manages to squeeze in there too. There is so much more that I want to plant there. I guess I should move out some of the plants that can handle drier conditions to make room.

Lobelia cardinalis
Carolina spiderlily (Hymenocallis caroliniana)

“Rain garden” is a popular term these days. “Official” rain gardens are often engineered with specific soil components to ensure that the water drains through. Search the web for rain garden definitions and you will find many guidelines on “how” to construct them. Here I want to talk about what native plants thrive in wet spots, whether you’ve engineered them or they are just naturally occurring.

First, you should understand that plants don't "soak up" the excess water, they tolerate it. Yes, they do use some the water themselves, but having wet tolerant plants won't make the water "go away".

Second, wet spots can be in sun or shade, so choosing the appropriate plants for the light level will result in a more beautiful effect. There is no sense in choosing full sun plants if they won't get enough light to bloom.

Here are some of the plants you can choose:

Perennials (sun):
Cardinal flower (Lobelia cardinalis) - also works in part shade
Swamp sunflower (Helianthus angustifolius)
Carolina spiderlily (Hymenocallis caroliniana)
Joe pye weed (Eupatorium/Eupatoriadelphus spp.)
Ironweed (Vernonia spp.)
Swamp hibiscus (Hibiscus coccineus)
Swamp milkweed (Asclepias incarnata)
Cup plant (Silphium perfoliatum
Jewelweed (Impatiens capensis) - also works in part shade

Asclepias incarnata

Hexastylis shuttleworthii

Perennials (shade):
Turtlehead (Chelone glabra)
Cinnamon fern (Osmunda cinnamomea)
Royal fern (Osmunda regalis)
New York fern (Thelypteris noveboracensis)
Lady fern (Athyrium filix-femina)
Shuttleworth ginger (Hexastylis shuttleworthii)
Foamflower (Tiarella cordifolia)

Foamflower (Tiarella cordifolia)
Viburnum nudum var. cassinoides

Possumhaw (Viburnum nudum and V. nudum var. cassinoides)
Virginia sweetspire (Itea virginica)
Winterberry  (Ilex verticillata)
Inkberry (Ilex glabra)
Elderberry (Sambucus nigra ssp. canadensis)
Florida anise (Illicium floridanum)
Summersweet (Clethra alnifolia)
Doghobble (Leucothoe spp.)
Buttonbush (Cephalanthus occidentalis)

Summersweet (Clethra alnifolia)

Magnolia virginiana

Bald cypress (Taxodium distichum)
Blackgum/Tupelo (Nyssa spp.)
Red maple (Acer rubrum)
River birch (Betula nigra)
Swamp dogwood (Cornus amomum or C. foemina)
Sycamore (Platanus occidentalis)
Sweetbay magnolia (Magnolia virginiana)

Blackgum (Nyssa sylvatica)
Cornus amomum

For those of you that live in a maritime area, there are plants more suited to the special conditions and types of water there. The Georgia Native Plant Society partnered with Coastal WildScapes to create a brochure of plants more suited to those wet conditions.

Note: this is my 100th blog, so a little "woo-hoo!" is in order. Thanks to all who have encouraged me to keep going since October 2010. I hope those that stop by will find what they are searching for as well as learn a little more about Georgia's native plants and how they can be used in our gardens and our landscapes.


  1. Yes, Ellen congrats on yur 100th blog piece.

    Rain gardens, the way I define them are not moist all the time. They are built to collect and absorb rainwater from a roof or parking lot. So during a drought, the rain garden would be dry, too. This way plants that crave constant moisture like cardinal flowers would not be a good choice--at least here in Florida where we have a 7-month dry season.

  2. I have the same situation. A small semi-wet spot mostly resulting from leaky gutters and poor drainage around a side of my house. It's GREAT for native plants though! I have Ironweed, summersweet, swamp sunflower, jewelweed, and black chokeberry (though technically I think the black is native farther north... but I am not 100% sure about it).

  3. Ginny, I have cardinal flower in a true rain garden does get dry...but I've got it on the eastern side of the house where it is shaded by the afternoon sun. Plus I live in North Carolina. Western, rainy, North Carolina. So while we do have dry spells, they are certainly not as distinguished as those of Florida! I just didn't want folks to think they couldn't plant cardinal flower without making a commitment to watering all of the time.

    Ellen--congrats on your hundredth post! I love that you included buttonbush, which is one of my all-time favorite blooms. Don't have the right spot for it in my yard. May have to sell the house!

  4. Thank you for this list. Even though I am in a different garden zone, I can use most of those plants.