available) and are less effective in filling open stands or for 

 maintenance and repair, therefore, good initial stands are 

 critical. 



(f) Definitely a cool weather grass, very sensitive to high 

 temperatures at transplanting. Poor survival can be expected 

 whenever air temperature exceeds 16° Celsius during or immedi- 

 ately following transplanting. This characteristic may account 

 for the lack of use of this plant on the Atlantic coast. 



(g) Fertilizer application is essential for success on 

 large mobile dunes. 



(h) Vigor declines rapidly with stilling of sand, making it 

 short-lived in the intermediate zone and requiring reinforcement 

 by planting of intermediate species, particularly on large dunes. 



(3) Sea Oats . A native warm season dune grass occurring from 

 about the Virginia Capes southward into Mexico and on some islands in 

 the Carribean Sea. Similar in appearance to American beachgrass but 

 with generally larger stems, more decumbent growth habit, and more open 

 stands (Figs. 17 and 18). The grass tends to dominate active foredunes 

 throughout much of its range. Its striking appearance, particularly 

 when in flower or fruit, has made legal protection necessary in some 

 States to avoid excessive harvest for ornamental purposes. Character- 

 istics of sea oats are: 



(a) Difficult and slow to multiply vegetatively, less than 

 half as fast as American beachgrass. Subject to pest problems 

 when grown away from the beach. Commercial availability is very 

 limited. 



(b) Spread into dune and beach areas is primarily by seeds. 

 Plants can be grown from seeds but are subject to pest problems 

 in the field. The grass is an erratic seed producer and seed 

 heads are heavily preyed upon by insects, birds, rodents, and 

 people. 



(c) Early growth of transplants and seedlings is very slow 

 and survival is erratic. Consequently, plantings of pure stands 

 usually are only marginally effective as sand trappers during the 

 year of establishment; therefore, it should rarely be planted 

 alone. Mixed with bitter panicum (southern range) and American 

 beachgrass or bitter panicum or both (northern range), sea oats 

 will tend to increase with time. 



(d) Trapping capacity develops rapidly after the first 

 year and even very spotty stands become effective with time. 



(e) It is more tolerant of reduced sand and nutrient 

 supply than American beachgrass; therefore, it persists 

 longer and provides more cover in the intermediate zone. 



35 



