Sunday, July 10, 2011

Coastal Plains Plants - Perfectly Placed

No doubt it seems intuitive that plants evolve to thrive in the places in which they are indigenous, but when it comes to every day gardening, not everyone seems to realize that.  Today's blog entry takes a look at plants and their communities in the area known as the Coastal Plain. Plants that grow there have adapted to this unique environment and make the case for choosing plants that are well suited for their growing conditions.

Live Oak, Quercus virginiana
Plants like this Live Oak, Quercus virginiana, draped in Spanish moss (Tillandsia usneoides):

I just finished a week of vacation in the area known as the Coastal Plain.  The Coastal Plain physiographic province makes up a large portion of Georgia south of the metro Atlanta area.  You can find more information here.  I was in the Lower Coastal Plain - just outside of Georgia, on Hilton Head Island, South Carolina.  Here is a picture showing the distribution of the Coastal Plain in the eastern U.S.  You can see that a large part of Georgia is included. 

I normally live in the area known as the Piedmont and am familiar with the plants that grow here.  But the sandy soils, rainfall patterns, air temperatures as well as the high percentage of wetlands (including tidal marshes and swamps) in the Coastal Plain require unique plant traits.  Some areas are well-drained while others are poorly-drained.  So the plants that grow here are perfectly suited to their environment - why not consider them when choosing plants for your garden?

It only took a couple of days on the island for me to be bored with the non-native ornamental landscaping that consumed the residential and commercial landscapes.  Everyone used the same plants - trees, shrubs and flowers - over and over.  I saw a sign for "Audubon Newhall Preserve" (link) and went to check it out to see if I could find out what plants really grow there.  I was not disappointed.

What follows is a summary of what I found. Much credit goes to the folks that created a superb trail guide with lots of plant and plant community details.  And of course all the credit for the Preserve itself goes to Caroline "Beany" Newhall, a determined woman who persuaded the Sea Pines Company to donate 50 acres for a nature preserve in 1965.  Since 1976 this has been managed by the Hilton Head Island Audubon Society.  The preserve includes a man-made pond created in 1965 and restored in 1993.

The predominant understory consists of saw palmetto (Serenoa repens) and wax myrtle (Morella cerifera).  I never get tired of pulling my hand across a wax myrtle branch and inhaling the spicy smell left behind.  In addition there was lots of Horse sugar (Symplocos tinctoria), inkberry (Ilex glabra), two different species of Lyonia (L. lucida and L. ferruginea), plus several different species of Vaccinium.  Less common, but marked for the education of visitors, were the following: Gordonia lasianthus, Persea borbonia, Ilex opaca, Ilex cassine, Ilex vomitoria, Buttonbush (Cephalanthus occidentalis), Cornus asperifolia, Viburnum obovatum, Osmanthus americanus, Chokeberry (Photinia pyrifolia), Clethra alnifolia, and Prunus angustifolia.  

The understory with lots of Saw Palmetto, Serenoa repens

Ilex glabra, Inkberry
Clethra alnifolia, Summersweet

The canopy layer had pines (4 different species according to the literature, including longleaf pine, Pinus palustris), Prunus serotina, Nyssa sylvatica, cabbage palm (Sabal palmetto), various oaks, persimmon (Diospyros virginiana), sweetgum (Liquidambar styraciflua), and Magnolia grandiflora.

Just as interesting as the plants was the ability to observe the different natural environments that made up the area: wooded areas, a pocosin (a bog-like wetland) , a man-made pond, and an area known as "pine flatwoods". These different environments made for a very diverse mix of plants and critters.  Including chiggers! (I know I'm not supposed to take anything away from the Preserve, but I do believe a few chiggers hitched a ride home with me.)

Campsis radicans, Trumpet creeper

There was a wide assortment of vines in the Preserve: Carolina jessamine, Virginia creeper, poison ivy, Smilax, trumpet creeper, grapes, and peppervine (Ampelopsis arborea).

Parthenocissus quinquefolia

The herbaceous layer was an assortment of interesting plants.  Bracken fern (Pteridium aquilinum) was predominant but we also saw other ferns like cinnamon fern, Virginia chain fern (Woodwardia virginica), and royal fern. Some of the other plants included Saccharum giganteum (giant beard grass), Muhlenbergia filipes (sweetgrass), vanillaleaf (Carphephorus odoratissimus), coral bean (Erythrina herbacea), and Yucca filamentosa (bear-grass).

The ripening beans of Erythrina herbacea

Ludwigia alternifolia
Rhexia alifanus

The pond area had several blooming plants: a form of Hypericum that was too far away to identify, a white Penstemon, meadowbeauty (Rhexia alifanus), and seedbox (Ludwigia alternifolia).

Sapium sebifera

Unfortunately, the invasive tallow tree (Sapium sebifera) had also landed in the area; nature preserves are very vulnerable to non-native infestations when the area can not be actively monitored. Hopefully it will be weeded out soon, but I saw it elsewhere on the Island so it will always be a threat.

In other areas on the island I saw more cool plants - devil's walking stick (Aralia spinosa) was just starting to bloom, and sea oats (Uniola paniculata) has made a nice recovery on the beach.

If you are looking for lists of native coastal plants that you might consider for your garden, be sure to check out the lists on the Coastal WildScapes webpage.


  1. That preserve is excellent. I don't think I've ever seen so many birds as I did there. And I think pine forests with palmetto understories are some of the neatest types of forests in Georgia. Thanks for sharing!

  2. Great post and summary of this plant community. I visited Savannah and Hilton Head a few years ago and wish I had read this then. When you're from the midwest, it can be overwhelming if you don't know any of the plants.

  3. If the Palmetto grasses can cope up with the stress, it will be healthy and dense and will be able to resist disease. Sometime the disease may spread and it becomes out of any control. However, the disease resistant cultivars can be implemented to avoid future problems.