Planting season and sand accumulation effects on Gulf Bluestem

Coastal dunes protect infrastructure from storm surge and are habitat for wildlife.  Restoration of storm damaged dunes requires reestablishment of coastal plants which trap and stabilize sand.  Gulf bluestem builds and stabilizes dunes along the Northern Gulf Coast and is a food source for endangered beach mice.  Its distribution is reportedly limited by excessive sand burial.  There is little information on the use of Gulf bluestem (Schizachyrium maritimum) for dune restoration.  The objective of this study was to examine effects of season of planting and sand accumulation on Gulf bluestem survival and growth.  Gulf bluestem was planted at 6 sites on Santa Rosa Island, Florida on, Nov. 11, 2005, Feb. 10, 2006, June 14, 2006 and Aug. 8, 2006 at two spacings (30 or 45 cm apart) with each spacing split by two accumulation regimes (natural sand accumulation or removal of accumulated sand).  Survival, height, basal area and tiller number were assessed in September 2007.  Survival was higher when planted in summer months (0% November, < 43% February, 100% June, 100% August).  Change in plant height (July-Sept)) was greater when planted in June compared to February.  For February plantings, change in plant height and basal area was significantly greater with 30 cm spacing. Sand accumulation at times was greater with 30 cm spacing.  Sand removal and wind scouring of sand decreased survival for bluestem planted in November and February.  Sand removal was more detrimental to plant survival than sand accumulation.  Fall and winter planting of bluestem is not recommended.