Selective Native Plants of Oklahoma and Nearby States That Can Be a Nuisance to Occasionally Invasive

Four ornamental species, lyreleaf salvia (Salvia lyrata), roughleaf dogwood (Cornus drummondii), northern sea oats (Chasmanthium latifolium), and cholla (Cylindropuntia imbricata), are all native to Oklahoma and nearby states. They all possess ornamental attributes and range from widespread to niche crops in the nursery industry and are also cultivated for their utilitarian, herbal, and miscellaneous merits. Their allure to customers and their ability to thrive in a myriad of environments is a major impetus for commercial growers and retailers to carry these species. However, their extraordinary ability to adapt to a plethora of environmental conditions, in the built environment or in their native range, also enables them to often outcompete neighboring flora. Their predisposition to be opportunistic, and ability to grow in challenging locations, sometimes results in their becoming a nuisance or even invasive (i.e., capable of displacing other native flora or fauna). Plants featured are described for their marketable attributes but also reviewed for control measures (e.g., herbicides, prescribed burning, improved grazing practices) when they grow in an aggressive manner.

Responses of Ornamental Grass and Grasslike Plants to Saline Water Irrigation

Ornamental grasses are popular in urban landscapes in Utah and the Intermountain West United States, one of the driest and fastest growing regions in the United States. This experiment evaluated the responses of five ornamental grass species [blue grama (Bouteloua gracilis), indian sea oats (Chasmanthium latifolium), ‘Blue Dune’ sand ryegrass (Leymus arenarius), pink muhly grass (Muhlenbergia capillaris), ‘Foxtrot’ fountain grass (Pennisetum alopecuroides)] and two ornamental grasslike species [fox sedge (Carex vulpinoidea), common rush (Juncus effusus)] to saline irrigation water in a greenhouse. Plants were irrigated weekly with a nutrient solution at an electrical conductivity (EC) of 1.2 dS·m–1 (control) or saline solutions at an EC of 5.0 or 10.0 dS·m–1. At the first harvest (9 weeks after the initiation of treatment), sand ryegrass, pink muhly grass, and fountain grass irrigated with solutions at an EC of 5.0 and 10 dS·m–1 had good visual quality with no or minimal foliar salt damage; however, the remaining species exhibited slight or moderate foliar salt damage. There were no significant differences in shoot dry weight (DW) among treatments within any species, except fox sedge and fountain grass. At the second harvest (18 weeks after the initiation of treatment), sand ryegrass, pink muhly grass, and fountain grass still had no or minimal foliar salt damage, and indian sea oats and fox sedge exhibited slight or moderate foliar salt damage. Compared with the control, all species irrigated with solutions at an EC of 10.0 dS·m–1 had reduced shoot DWs with the exception of blue grama. However, only common rush and pink muhly grass irrigated with solutions at an EC of 5.0 dS·m–1 had lower shoot DWs than the control. These results demonstrated that seven ornamental grass or grasslike species had a very strong tolerance to the salinity levels used in the 4-month experiment. Although plant growth was inhibited as a result of saline irrigation, plant visual quality of sand ryegrass, pink muhly grass, and fountain grass was still acceptable. These three species appear to be more suitable for landscapes in which saline irrigation water is used. Further research is needed to evaluate more ornamental grasses for landscapes in salt-prone areas and nearby coastal regions.

Sea Oats, Uniola paniculata

Sea oats occur throughout Florida on beach dunes and beaches and on coastal areas west to Texas and north to Maryland. Sea oats are vital dune builders that accumulate sand and prevent erosion due to wind, waves, and large storms. As sand is trapped by the long leaves of sea oats, vertical growth is stimulated, and rooting occurs at the buried nodes. This plant is extremely drought- and salt-tolerant, grows up to the high tide line of beaches, and propagates both vegetatively and by seed in the wild (Shadow 2007).https://edis.ifas.ufl.edu/sg186 This publication is derived from information in SGEB-75/SG156, Dune Restoration and Enhancement for the Florida Panhandle, by Debbie Miller, Mack Thetford, Christina Verlinde, Gabriel Campbell, and Ashlynn Smith. https://edis.ifas.ufl.edu/sg156.

Bitter Panicgrass, Bitter Panicum, Panicum amarum

Bitter panicgrass is important in dune stabilization and building and often grows intermixed with sea oats onforedunes. It is also found spread throughout back dunes, interdunal swales, and coastal grasslands. This plantoccurs throughout coastal Florida, except for the Big Bend coast, west to New Mexico, and along coastal northeast states to Massachusetts. A significant proportion of bitter panicgrass reproduction is by vegetative spread; its seeds are often sterile.https://edis.ifas.ufl.edu/sg178 This publication is derived from information in SGEB-75/SG156, Dune Restoration and Enhancement for the Florida Panhandle, by Debbie Miller, Mack Thetford, Christina Verlinde, Gabriel Campbell, and Ashlynn Smith. https://edis.ifas.ufl.edu/sg156.

Gulf Bluestem, Maritime Bluestem, Schizachyrium maritimum

Gulf bluestem occurs throughout the Florida Panhandle and in neighboring coastal states. Gulf bluestem helpsstabilize dunes, forms thick stands in areas leeward of slopes (Craig 1991), replaces sea oats as the dominant species on protected foredunes behind a seaward ridge after 2 to 17 years (Johnson 1997), and occurs throughout flatwoods and disturbed areas. This plant is very closely related to little bluestem (Schizachyrium scoparium), and its taxonomic position is not entirely agreed upon by taxonomists; hence information may also be located using the taxonomic synonym Schizachyrium scoparium var. scoparium.https://edis.ifas.ufl.edu/sg184 This publication is derived from information in SGEB-75/SG156, Dune Restoration and Enhancement for the Florida Panhandle, by Debbie Miller, Mack Thetford, Christina Verlinde, Gabriel Campbell, and Ashlynn Smith. https://edis.ifas.ufl.edu/sg156.

Improving Sea Oats Seedling Production from Seed with Fungicides

In Louisiana, sea oats (Uniola paniculata) are incorporated into beach restoration projects to build and stabilize sand dunes. Unfortunately, sea oats seed yield, germination, and seedling survival are poor. The objectives of this study were to assess the impact of commercial fungicide(s) on sea oats germination, seedling survival, and seedling quality. Sea oats seed were planted into soilless media and grown in greenhouse conditions in Baton Rouge, LA. Four fungicide treatments at two rates were applied to seeded trays: mefenoxam, thiophanate-methyl, azoxystrobin, and iprodione. Two control treatments were included: a 15-minute seed soak in water before seeding and dry seed. Percentage germination, percentage survival, shoot height, and fresh weight were measured. Sea oats seed treated with thiophanate-methyl at twice the fungicide label’s recommended rate [2× (23.0 oz/1000 ft2 a.i.)] had the greatest mean germination and survival and were the tallest seedlings 8 weeks after seeding. These results strongly suggest that treating seed with thiophanate-methyl 2× increased sea oats germination, survival, seedling quality, and profitability of sea oats production. The cost to apply thiophanate-methyl 2× to 1000 sea oats seed was $1.74. The additional revenue generated from greater germination, survival, and seedling quality when growing media was treated with thiophanate-methyl 2× was $37.72 per 1000 sea oats seeds. Therefore, the fungicide thiophanate-methyl was identified to be a practical and economical method to rapidly produce a large number of genetically diverse sea oats plants.

Development and Evaluation of Methods to Identify Sea Oats Breeding Lines for Beaches with Shallow Dunes

Sea oats (Uniola paniculata) is an aesthetically pleasing native plant used for beach restoration along the northern Gulf of Mexico coast. Many beaches in this region have shallow, saturated dune profiles, which reduces sea oats survival. The objective of this study was to develop methods to identify saturation-tolerant sea oats breeding lines. Sea oats seedlings were evaluated for saturation tolerance in greenhouse, beach, and field environments from 2010 to 2012. In 2010, sea oats grown under eight treatments (seven greenhouse treatments and a natural beach site) were examined. In 2010, sea oats seedling survival 2 and 3 months after transplanting (MAT) was greatest for four greenhouse treatments (nonflooded control, 6 cm cyclic flood, 6 cm static flood, and 10 cm cyclic flood) and least at the beach environment (Holly Beach, LA). In 2011 and 2012, sea oats grown under six treatments (four greenhouse treatments, a natural beach site, and a saturated field site) were examined. In 2011, sea oats seedling survival 3 MAT ranged from 0.3% to 98%. The nonflooded greenhouse control had the greatest survival, whereas plants grown on dry bench regularly watered with 35 parts per thousand (ppt) saline solution had the least survival. Sea oats constantly flooded with 14 cm of saline water in the greenhouse had the least survival 2 and 3 MAT, 70% and 41%, respectively. Sea oats survival when flooded with 14 cm of fresh water 3 MAT correlated with a saturated beach environment, Holly Beach, LA, 6 MAT (r = 0.970, P = 0.030) and a saturated field environment, Baton Rouge, 6 MAT (r = 0.994, P = 0.006). These findings suggest that survival of sea oats grown in a greenhouse in 14 cm fresh water for 3 months correlates to sea oats survival at saturated beaches after 6 months, in the absence of significant storm events. Identifying protocols for selection of saturation-tolerant sea oats lines is essential to increase the efficiency and effectiveness of northern Gulf of Mexico sea oats breeding programs.