Ornamental grasses have recently increased in popularity in the landscape and nursery industry (Cameron, 2004; Thetford et al., 2009). Most ornamental grasses are grown in containers, and are inherently more susceptible to winter damage from exposure to cold or freezing temperatures than field-grown plants (Perry, 1998). Consequently, some commercial growers in the mid-Atlantic United States experience significant losses of crops such as fountain grass during the overwintering period (I. Brantingham, personal communication; S. Epps, personal communication; M.J. Packett, personal communication).
Thetford et al. (2009) evaluated the landscape performance of HFG in northern Florida [United States Department of Agriculture (USDA) Hardiness Zone 8b] and characterized its performance as marginal or visually acceptable. The performance of fountain grass would likely be impaired in the mid-Atlantic United States, especially in container production systems that are less buffered against cold temperatures. This impairment associated with cold temperatures has been demonstrated in a wide variety of perennials (Dimke et al., 2008). Under these conditions, growers may use thermal blankets, unheated coldframes, and heated greenhouses to protect container-grown plants from damaging winter temperatures (Smith, 2004).
Several cultural factors, such as the use of substrate moisture content (Smith, 2004), protective covers (Perry, 1998), and fertility level (Bilderback and Bir, 2007) have been identified to affect the overwintering survival and spring vigor of container-grown plants. However, the optimal management of these factors for the production of fountain grass has not been identified. Further research on this topic may lead to economical improvements in overwintering survival and subsequent spring vigor for fountain grass growers.
This study was conducted to determine the effect of substrate moisture content, protective covers, and fertilizer application rate on the survival rate and vigor for SFG and two dwarf selections of fountain grass, HFG and LBFG; we use the term “cultivars” to refer to the group. Plants were selected based on popularity, availability, and grower-reported problems with overwintering (I. Brantingham, personal communication; S. Epps, personal communication; M.J. Packett, personal communication).
Bilderback, T. & Bir, R. 2007 Preparing nursery plants for winter. North Carolina Coop. Ext. Serv. Bul. AG-454. 15 Jan. 2011. <http://www.ces.ncsu.edu/depts/hort/hil/ag454b.html>
Cunliffe, B.A. & Meyer, M.H. 2002 Propagation time affects winter survival and finishing date for ornamental grasses J. Environ. Hort. 20 201 203
Dimke, K.C., Still, S.K. & Gardner, D.S. 2008 Effect of overwintering environment on the survival of 30 species of herbaceous perennials J. Environ. Hort. 26 222 228
Emerald Coast Growers 2010 Grower cultural information for Pennisetum alopecuroides, Pennisetum alopecuroides ‘Hameln,’ and Pennisetum alopecuroides ‘Little Bunny.’ 11 June 2011. <http://www.ecgrowers.com/Pennisetum-Grasses-s/107.htm>
Perry, L. 1998 Herbaceous perennials production: A guide from propagation to marketing. Northeast Reg. Agr. Eng. Serv. Publ. NRAES-93
Proven Winners 2011 Professional grower resources for Pennisetum alopecuroides. 14 Sept. 2011. <http://www.pwcertified.com/grower/plants/>
Smith, T.M. 2004 Overwintering containerized perennials. 15 Jan. 2011. <http://www.umass.edu/umext/floriculture/fact_sheets/specific_crops/overwint.html>
Thetford, M., Norcini, J.G., Ballard, B. & Aldrich, J.H. 2009 Ornamental landscape performance of native and nonnative grasses under low-input conditions HortTechnology 19 267 285
Walters Gardens 2011 Cultural sheets for Pennisetum alopecuroides and/or orientalis. 14 Sept. 2011. <http://www.waltersgardens.com/growerscorner/?page=85&sheet=94>