Blue Water Lily
Day Flower & Widow Tears
Salt Marsh Fleabane
Sea Ox-Eye Daisy
Seaside & Small Coast Germander
Soft Stem Bulrush
White-Topped Umbrella Grass
Wright's Hairy Crown
Yellow Water Lily
Yellow Water Lotus
|NATIVE POND AND WETLAND PLANTS of the Lower Rio Grande Valley, Texas
LANDSCAPE USES AND IDENTIFICATION
by the Native Plant Project
SCIENTIFIC NAMES OF SPECIES IN THIS BOOK
Emergent Areas or Bog
Commelina elegans & C. erecta
Sisyrinchium angustifolium & S. biforme
Teucrium canadense & T. cubense
TABLE OF CONTENTS
Planting Wetland Plants
Pruning Bog Plants
Pruning Pond Plants
Plant Communities of the Lower Rio Grande Valley
References and Further Reading
Bulrush, Soft Stem
Hairy Crown, Wright's
Umbrella Grass, White-topped
Emergent Areas or Bogs
Germander, Seaside & Small Coast
Salt Marsh Fleabane
Sea Ox-eye Daisy
Water Lily, Blue
Water Lily, Yellow
Water Lotus, Yellow
An estimated 1,200 native flowering plant species grow in the Lower Rio Grande Valley, Texas. The Native Plant Project has selected a varied sampling of the native aquatic pond and wetland plants to be featured in this handbook.
Plants native to the Lower Rio Grande Valley have advantages over plants brought in from elsewhere. Plants from this region have the genetic factors which ensure greater probability of survival. They are preadapted having evolved to tolerate local climatic extremes, local soils, and local diseases and pests. Native plants have evolved with temperature and rainfall extremes and will require less water than exotic plants.
Using native plants helps conserve rarer species which are vanishing due to habitat clearing. Within the four-counties (Cameron, Hidalgo, Starr, and Willacy) of the Lower Rio Grande Valley over 98% of the natural habitat has been converted or cleared for urban, agricultural, or industrial use. Establishing rare species in landscapes spreads out the individuals so one catastrophe cannot take out a species all at once and also provides a reserve seed source in the event the last individuals of a species are eradicated from the natural habitat.
A few of our native pond and wetland plants may be available from nurseries in the Lower Rio Grande Valley. Rarer ones can be found only at the few nurseries specializing in Lower Rio Grande Valley natives. (See list inserted in handbook.) More and different native plants will become available if you demand them. Nurseries will provide greater selections of natives if they know there is a demand for the plants. The Native Plant Project will provide sources upon request.
Founded in 1982, the Native Plant Project's purpose is to protect and conserve the native plants (including endangered), habitats and environment of the Lower Rio Grande Valley and promote the use of local native plants in local landscapes. One method it uses is disseminating information about native plants and habitats. Its definition of a native plant is one indigenous to the four-county area of the Lower Rio Grande Valley.
The Native Plant Project encourages the protection of native plants through conserving and restoring native habitats in refuges, natural areas in parks and wildlife management areas, and private sanctuaries. It works to protect both natural habitat and human-influenced environments. It encourages the conservation of native species through inclusion in local landscaping. The Native Plant Project works cooperatively with the U.S. Fish and Wildlife Service, Texas Natural Heritage Program, Texas Parks and Wildlife Department and many private organizations toward protecting Endangered Species, including those local natives imperiled but not unlisted.
The Native Plant Project currently holds general meetings eight times per year. Members are advised of meetings, field trips and other activities through The Sabal, which conveys information on the native plants, habitats, and the environment of the lower Rio Grande Valley. The Native Plant Project periodically updates and issues lists of endangered species of the Lower Rio Grande Valley and checklists of the woody plants.
The choice of a native aquatic plant, like any other plant, should be dictated by landscaping needs and the desired effect. Given the limits of purpose and site, finding an aquatic plant which will handsomely fulfill every requirement is no problem. Once a choice is made there remain only a few location and planting tips to be observed. Aquatic plants grow in three site zones. Bogs or meadows are areas that stay moist but do not have standing water. Shrubs and even trees are known to grow in this environment as evidenced by the low lying areas around resacas in the Rio Grande Valley. Emergent areas have standing water and contain plants that grow with their roots in soil but their stems and leaves above water exposed to sun and air. Cattails, arrowhead, sedges, reeds and grasses are emergent species. Deep water zones contain at least 8 inches of water at all times. Deep water plants are usually rooted with leaves floating on the surface and blooms either floating or rising above the water. Water lilies and lotus are two such plants.
• Obtaining Plants
First, get your pond and wetland plants from a reputable, reliable nurseryman. DO NOT transplant from the wild. Not only is this rarely successful, it diminishes our already threatened natural plant and animal habitats. A healthy, vigorous looking aquatic plant, purchased in a nursery, has a better survival rate than one taken from its natural habitat. Besides survival, another problem with taking plants from the wild is the introduction of undesirable elements into your pond. It is difficult to dig an aquatic plant without getting grasses or other unwanted plants in the soil.
The rising interest in using native plants in landscaping has in some cases exceeded the supply at local nurseries. Insistence and frequent inquiries on the part of the consumer may bring about enlightenment and a willingness on the retailer's part to meet the demand. Diligent searching can result in locating most of the plants listed within this publication.
• Site location
Second, most native aquatic plants need a location similar to their natural habitat. Bogs, streambeds, and ponds constructed in landscapes can replicate these sites very well. Low areas that retain water or remain moist within the landscape provide ideal conditions for many aquatic specimens. These emergent or bog sites may undergo an occasional dry period, or intermittent periods of wet and dry.
Marginal plants grow at the edge of permanent wet areas. They survive best when their roots are always covered with at least a few inches of water. Marginals are best suited to shallow shelves within ponds, or the edges of flowing streams. Deep water plants like water lilies and lotus can be planted in ponds 12 - 30 inches deep.
Be aware of the amount of sunlight your site will receive. While most marginal plants can tolerate very shady locations, lilies and lotus require at least six hours of sun a day.
PLANTING WETLAND PLANTS
• When to Plant
The best time to plant aquatics in the Rio Grande Valley is early autumn (to allow for root establishment and dormancy before any freeze) and any time after early March. Most native aquatic plants will go dormant during the winter and not emerge until warmer weather. The rule of thumb is that the deeper the water depth in which the aquatic is planted, the later it emerges. Tropical water lilies and lotus bloom much later than hardy lilies.
• Preparing the site
If no natural site exists, an artificial bog may be constructed by digging an area to a depth of 18 inches and placing a non-permeable liner in the excavation. Bring the edge of the liner to within 1 inch of the ground level and refill with excavated soil, sand or improved soil made by mixing at least 1:1 removed soil to moist peat moss or other organic material. A layer of 3 - 4 inches of gravel should be added to the top of the bog.
Construction of ponds is too lengthy a subject to be addressed in this publication. Many fine resources are available for the do-it-yourselfers or professional assistance may be needed.
• Setting plants in a bog
A hole in the prepared bog should be dug sufficiently deep and wide enough to hold the full root system. The depth of the top of the root system should NOT be lower than the top of the hole. If planted too deep the plant may not survive. Remove the plant from the container. If roots are so numerous they are encircling the soil ball, cut the root ball vertically with a sharp knife to a depth of 2 inches on opposite sides of the ball to encourage roots to grow outward. After setting the shrub in the hole, soil should be added gradually working the first bit in firmly at the base of the root ball, then filling the hole with more soil. Remove all air holes and continue to fill until you have covered the root ball to its original depth. Gravel can be added as a ground cover around bog plants.
• Setting plants in a pond
Aquatics can be planted in pots and placed in ponds at the appropriate depth. Remember to plant each plant at the same level as it was previously growing. If a more natural pond is desired, plants may be planted in "plant bags" made of weed barrier fabric. These can be purchased from local nurseries that carry water garden supplies or you can make one by cutting a piece of fabric large enough to hold the root system of your plant with a few extra inches. Place a small amount of clay soil in the center of the fabric, position the plant's roots over the soil, then continue to add soil to cover the roots. Bring the fabric up around the roots and tuck the plant bag among the rocks in the bottom of the pond, at the appropriate depth.Some plants require little or no soil. They root in water and draw all of the nutrients they require from the water. These plants will usually be anchored on the bottom or side of a pond and float across the surface. They may have an extensive floating root system.
PRUNING BOG PLANTS
In their native habitat, most bog plants experience periodic dry spells in which the plants will die back or go dormant. Without this naturally occurring control, bog plants can continue to grow and spread all year long and can become invasive. Most of these plants spread by runners and will fill in a bog and choke out smaller plants. Judicious removal of newly emerging plants is the best and easiest means of controlling rampant spreading. One method of controlling the spread of under ground roots is to plant aquatics like Germander in containers that have no holes. This will slow the spreading process, but not control it completely.
PRUNING POND PLANTS
It is necessary to remove spent flowers and old leaves from water lilies on a regular basis. Dead flowers and foliage will sink to the bottom of your pond and decompose if not removed. Removal of some leaves may be necessary during periods of intense growth, an over abundance of leaves may cover too much of the pond surface.Floating aquatics that root in the water, such as Water hyssop and Water primrose will need to be pruned back occasionally. These, like lilies, will cover too much surface if left unchecked.
PLANT COMMUNITIES OF THE LOWER RIO GRANDE VALLEY
Plant communities in the Lower Rio Grande Valley (LRGV) are part of the South Texas (or Rio Grande) Plains which constitute most of the Texas half of the Tamaulipan Biotic Province. The entire Lower Rio Grande Valley lies on the Gulf Coast Plain that extends across the LRGV and Rio Grande River to the Sierra Madre Oriental of Mexico and its surrounding area. The western part of the LRGV (Falcon Woodland) is also the easternmost part of the shrub-dominated Chihuahuan Desert. Plains and brush land plants reach the LRGV from the north, and more eastern plants line the Rio Grande. Several plants have disconnected Trans-Pecos and LRGV distributions. Coastal plants reach the LRGV from north and south. Subtropical plants also lend their unique character to the LRGV's subtropical appearance.
Water availability, soil type, and temperature are the predominate non-human determinants of the LRGV's unusually varied and unique vegetation communities and habitats. Five major plant areas include barrier islands, coastal, riparian woodlands, shrub lands (chaparrals), and sand plain grassland. Each of these five general areas consists of many diverse associations and habitats. The LRGV lacks perennial streams and few historic springs survive.
The four-county LRGV is enclosed by the Gulf Mexico on the east, waterless Sand Plain containing La Sal Viejo and La Sal Del Rey on the north, and an arbitrary (county) line on the west between Falcon Reservoir (in the Chihuahuan Desert) and the Sand Plain. The Bordas Scrap in Starr County is the major component of relief. The Rio Grande, or Rio Bravo as it is know in Mexico, separates the Texan and Tamaulipan portions of the LRGV. The nonpolitical southern boundary is another waterless area between the Rio Grande and the Rio San Fernando. The area of the Rio Grande Delta consists of the flood plain broadening eastward, including Cameron, Willacy and southern Hidalgo Counties and a similar area in Tamaulipas, Mexico. The tree-life and water distribution somewhat characterize these five areas. The barrier islands lack trees and the few scattered shrubs never exceed one meter in height. The coastal communities have a few stunted Texas Ebony or Honey Mesquite trees on halophytic, shrub-covered lomas. Freezes permitting, characteristic Black Mangrove shrubs grow near the coastal brackish waters or marshes. The riparian woodlands and palm jungles cover open or dense shrub layers, which line the Rio Grande and it's resacas. The dry shrub lands consist of short trees and shrubs with taller trees around depressions or potholes. The Sand Plain and its bordering habitat lack trees except for isolated groupings surrounded by a sea of grass. Many shrubs in western and northern LRGV can shed leaves during drought stress and regrow them after rain.
Because of little variation in temperature across the LRGV, our trees, shrubs, and plants can be grown under a wide variety of conditions with only minor modification of site and care. Riverbank-adapted plants require more water than will other natives. Where necessary, this handbook includes such modifications in hope of improving success when using one of the LRGV native plants in your landscape.
REFERENCES AND FURTHER READING
Burrell, C. Colston. 2000. The Natural Water Garden. Brooklyn
Glattstein, Judy. 1994. Waterscaping, Plants and Ideas for Natural and Created Water Gardens. Story Communications, Inc., Pownal.
Loughmiller, C. and Lynn Loughmiller. 1999. Texas Wildflowers: Foreword by Lady Bird Johnson. University of Texas Press, Austin.
Native Plant Project. 1994. Native Trees of the Lower Rio Grande Valley, Texas. Landscape Uses and Identification. Native Plant Project, Edinburg.
Native Plant Project. 1996. Native Shrubs of the Lower Rio Grande Valley, Texas. Landscape Uses and Identification. Native Plant Project, Edinburg.
Native Plant Project. 2000. Native Plants: Cacti, Ground Covers and Vines of the Lower Rio Grande Valley, TX Landscape Uses and Identification, Native Plant Project, Edinburg.
Richardson, A. 1995. Plants of the Rio Grande Delta. University of Texas Press, Austin.
Richardson, A. 2002. Wildflowers and Other Plants of Texas Beaches and Islands. University of Texas Press, Austin.
Stutzenbaker, Charles D. 1999. Aquatic and wetland plants of the Western Gulf coast. Texas Parks and Wildlife, Austin.
Wasowski, Sally, with Andy Wasowski. 1988. Native Texas Plants: Landscaping Region by Region. Texas Monthly Press, Austin.
THE NATIVE PLANT PROJECT of the Lower Rio Grande Valley
The Native Plant Project currently holds general meetings eight times per year. Members are advised of meetings, field trips, nature festivals and other activities through The Sabal, which conveys information on the native plants, habitats, and the environment of the Lower Rio Grande Valley, Texas.
Native Plant Project
P.O. Box 2742
San Juan, TX 78589
The Native Plant Project wishes to thank Gene Lester for generating this handbook along with the technical assistance of Sue Griffin. Gene Lester with the technical assistance of Joe Ideker is credited for generating the three previous handbooks; 1) Native Trees, 2) Native Shrubs, and 3) Native Plants: Cacti, Ground Covers and Vines. Thanks is given to the Board Members for producing this handbook.
To order additional copies of this handbook contact:
Valley Nature Center
301 South Border Avenue
P.O. Box 8125
Weslaco, TX 78596