Shorescaping Freshwater Shorelines

Shorescapes

South Carolina is blessed to have an abundance of water resources in the form of rivers, lakes, ponds and estuaries, and many residents own properties that adjoin these beautiful watercourses. This presents the waterfront owner with a unique opportunity to discover a largely unexplored form of gardening - SHORESCAPING. A shorescape is a landscaped shoreline that uses attractive plants to protect and beautify the waterfront. A well designed shorescape uses native plants to provide a functional solution to problems such as shoreline erosion, poor water quality, invasive weeds, and wildlife management. Also, like a flower bed in the yard, a shorescape that uses a mixture of flowering plants can serve as a waterfront garden that improves the appearance of the shoreline and adds value to the property. Luckily, there are many very attractive plants that are easy to grow, native to South Carolina, and suitable for use in a most shorescapes.

Before Planting

Before planting, you should consider carefully what your designated uses are for the body of water. For instance, residential stormwater ponds and recreational fish ponds need to have open shorelines with few trees so that they can be accessed easily for maintenance and use. On the other end of the spectrum, trees may be necessary for properties along rivers and large reservoirs to withstand the strong erosional forces present in these large systems. Also, the waterfront owner should consider how the waterway is used by neighbors and the community. Plants should not be placed in areas that may restrict recreational use or navigation. In the case of residential ponds, the community relies on the ponds to convey stormwater runoff from the neighborhood through a system of pipes and outfalls. The waterfront owner should be careful not to obstruct these conveyances which, if clogged, could cause flooding. In some cases, it is the responsibility of the home owners association to determine what plants are suitable for stormwater pond banks. For more information about protecting water resources, visit www.clemson.edu/carolinaclear.

Right Plant, Right Place

Knowing what to plant and where to plant them is the greatest challenge for designing a shorescape because the shoreline is an ecotone (an area of transition between two ecosystems). Waterfronts have four distinct zones which characterize the transition from water to land. Each zone is suitable to different plants based on the water needs of each plant. The following section provides descriptions of the planting zones and lists of plants suitable for each zone.

When purchasing plants, check the scientific names and match them to the plants on this list. Many plant species share common names, but may differ from those described here.

Maintaining Your Shorescape

Pesticides and fertilizers should be avoided in a shorescape if possible because of the potential for runoff into the water. Weed control is best done by hand pulling. If herbicides are necessary, it is best to use herbicides that are labeled for aquatic use because they have less potential for causing water quality problems. Undesirable trees, vines, shrubs and tall weeds can be eliminated using a hack and squirt method which involves the application of a systemic herbicide directly to the cut stem of the undesirable plant. Mulch can be used in the upland zone but may be carried away by high water if it is placed in the riparian zone. Instead, space plants closely so that there is less potential for weeds to invade the shorescape. The crowns of plants in the shorescape need to be cut back and harvested once each year before the spring growing season begins. The mowed or cut plant material should not be left in place or allowed to wash into the water because it may cause water quality problems or block water flow.

Shorescapes Around Stormwater Ponds

Stormwater ponds in residential communities present a unique set of conditions that deserve special consideration. Stormwater ponds are designed to be open basins that capture stormwater runoff from roads, rooftops, and yards in the community 1) to moderate the storm surge and prevent flooding and 2) to trap and treat polluted runoff to protect water quality. To that end, stormwater ponds need to be free of obstructions such as large trees and shrubs on the banks and excessive submersed and floating vegetation that takes up space and impedes flow. Special attention also needs to be paid to preventing plants from growing over inlet pipes and outfalls. In addition to these functional concerns, many communities have concerns over the appearance of the pond banks, to the extent that the homeowners association restricts what can be planted on the bank slopes. To balance the functional and aesthetic needs of residential ponds, here is a short list of shoreline plants suitable for stormwater ponds throughout the state along with brief descriptions of each plant.

Zones

The Littoral Zone – the area below the water line that is too deep for emergent plants but still shallow enough that sunlight can penetrate through the water to the bottom. The littoral zone usually is 1 to 4 feet deep but may be deeper if the water is very clear. Many aquatic plants that grow in the littoral zone can be invasive, especially in shallow stormwater ponds, so it is important to manage submersed and floating-leaved vegetation to prevent clogged outfalls and fish kills.

Plants for the Littoral Zone:
Coontail Ceratophylum dimersum
Tape-grass Vallisneria americana

The Emergent Zone – the part of the bank slope that lies below the water line but is shallow enough to allow emergent aquatic plants to root in the submerged soil and grow upward above the water’s surface. The emergent zone is usually less than 12 inches deep. Avoid emergent plants that have a “creeping” lateral growth habit such as water primrose and alligatorweed. Vertical plants are easier to manage in the emergent zone.

Plants for the Emergent Zone:
Pickerelweed Pontederia cordata
Arrowheads Sagittaria latifolia, S. lancifolia
Arrow Arum Peltandra virginicus
Lizard’s Tail Saururus cernuus
Alligator Flag Thalia geniculata*
Golden Canna Canna flaccida*
White Star Sedge Dichromena colorata*

The Riparian Zone – the part of the bank slope that lies above the water surface but where the soil remains permanently wet and saturated. The riparian zone often is inundated with water when pond levels rise during storms. Plants that thrive in this zone need moist soils and can withstand extended periods submerged under water but prefer to grow at or just above the water line.

Plants for the Riparian Zone:
Soft Rush Juncus effusus*
Bulrush Scirpus spp.*
Louisiana Iris Iris (hexagonae group)
Blue/Yellow Flag Iris virginica, I. pseudocoris
Spider Lily Hymenocallis palmeri
Mallow Hibiscus Hibiscus moscheutos*
Swamp Sunflower Helianthus angustifolius*
Cardinal Flower Lobelia cardinalis
Bog Lily Crinum americanum
River Oats Chasmanthium latifolium*
White-top Sedge Dichromena colorata*
Lizard’s Tail Saururus cernuus*

The Upland Zone – the part of the bank slope above the riparian zone where soils do not stay permanently moist. This zone often is very dry because the slope forces water to runoff rather than seep into the ground. Upland zones with very steep slopes will need plants that are very drought tolerant. In most cases, the ornamental plants that are commonly used in the home landscape are useful in this zone. Residents that live next to stormwater ponds in residential neighborhoods should avoid planting trees and large shrubs on the bank slopes. Perennials and grasses are best in this zone.

Plants for the Upland Zone:
Native Grasses* (Weeping Love Grass, Big Bluestem, Muhly Grass, Switchgrass, Indian Grass) 
Native Perennials (Butterfly Weed, False Indigo*, Tickseeds, Coneflower*, Hardy Ageratum, Blazing Star, Verbena*, Goldenrod)
Other Perennials (Sunflower Heliopsis, Daylily*, Bearded Iris*, Red Hot Poker, Lantana*, Lavender*, Creeping Phlox, Salvia, Stonecrop, Purple Heart)

The Littoral Zone – the area below the water line that is too deep for emergent plants but still shallow enough that sunlight can penetrate through the water to the bottom. The littoral zone usually is 1 to 4 feet deep but may be deeper if the water is very clear. Many aquatic plants that grow in the littoral zone can be invasive, especially in shallow stormwater ponds, so it is important to manage submersed and floating-leaved vegetation to prevent clogged outfalls and fish kills.

Plants for the Littoral Zone:
Coontail Ceratophylum dimersum
Tape-grass Vallisneria americana

The Emergent Zone – the part of the bank slope that lies below the water line but is shallow enough to allow emergent aquatic plants to root in the submerged soil and grow upward above the water’s surface. The emergent zone is usually less than 12 inches deep. Avoid emergent plants that have a “creeping” lateral growth habit such as water primrose and alligatorweed. Vertical plants are easier to manage in the emergent zone.

Plants for the Emergent Zone:
Pickerelweed Pontederia cordata
Arrowheads Sagittaria latifolia, S. lancifolia
Arrow Arum Peltandra virginicus
Lizard’s Tail Saururus cernuus
Alligator Flag Thalia geniculata*
Golden Canna Canna flaccida*
White Star Sedge Dichromena colorata*

The Riparian Zone – the part of the bank slope that lies above the water surface but where the soil remains permanently wet and saturated. The riparian zone often is inundated with water when pond levels rise during storms. Plants that thrive in this zone need moist soils and can withstand extended periods submerged under water but prefer to grow at or just above the water line.

Plants for the Riparian Zone:
Soft Rush Juncus effusus*
Bulrush Scirpus spp.*
Louisiana Iris Iris (hexagonae group)
Blue Flag Iris virginica
Spider Lily Hymenocallis palmeri
Mallow Hibiscus Hibiscus moscheutos*
Swamp Sunflower Helianthus angustifolius*
Cardinal Flower Lobelia cardinalis
Bog Lily Crinum americanum
River Oats Chasmanthium latifolium*
White-top Sedge Dichromena colorata*
Lizard’s Tail Saururus cernuus*

The Upland Zone – the part of the bank slope above the riparian zone where soils do not stay permanently moist. This zone often is very dry because the slope forces water to runoff rather than seep into the ground. Upland zones with very steep slopes will need plants that are very drought tolerant. In most cases, the ornamental plants that are commonly used in the home landscape are useful in this zone. Residents that live next to stormwater ponds in residential neighborhoods should avoid planting trees and large shrubs on the bank slopes. Perennials and grasses are best in this zone.

Plants for the Upland Zone:
Native Grasses* (Weeping Love Grass, Big Bluestem, Muhly Grass, Switchgrass, Indian Grass) 
Native Perennials (Butterfly Weed, False Indigo*, Tickseeds, Coneflower*, Hardy Ageratum, Blazing Star, Verbena*, Goldenrod)
Other Perennials (Sunflower Heliopsis, Daylily*, Bearded Iris*, 
Red Hot Poker, Lantana*, Lavender*, Creeping Phlox, Salvia, Stonecrop, Purple Heart)

*Special note* Many ponds have large populations of ducks and geese which can damage shoreline plants by trampling and grazing. Plants marked with an asterisk (*) are known to be resistant to waterfowl damage.

Shoreline Plants for Stormwater Ponds

For more detailed information about designing your waterfront to stop erosion, protect water quality, and beautify your shoreline, consider obtaining a copy of Life at the Water's Edge. Life at the Water's Edge has 150 pages of detailed information on the benefits and design of landscaped waterfronts. It includes more than 135 color photos and illustrations, a glossary of terms, an appendix of plants mentioned, and a plant list for South Carolina lakeshore and streamside buffers. This book can be purchased at your county Extension office or online from Clemson PSA Publishing at https://shopping.clemson.edu. 

Content reviewed by:
Mary Caflisch, Clemson Extension Service; Cathy Reas Foster, Clemson Extension Service; Sarah White, Clemson University; Katie Giacalone, Clemson Carolina Clear.

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