Greenhouse Production of Native Aquatic Plants

Abstract

Wetland restoration is critical for improving ecosystem services, but many aquatic plant nurseries do not have facilities like those typically used for large-scale plant production. We questioned if we could grow littoral aquatic plant species in a variety of substrates and irrigation methods similar to those used for traditional greenhouse production. Plants were grown in pots with drainage holes that were filled with potting substrate, topsoil, coarse builders’ sand, or a 50/50 mix of topsoil and builders’ sand. These substrates were amended with 2 g of 15N–3.9P–10K controlled-release fertilizer per liter of substrate and were watered using either overhead irrigation or subirrigation. Plants were grown for 16 weeks, then scored for quality and height before a destructive harvest. Blue-eyed grass (Sisyrinchium angustifolium) and arrow arum (Peltandra virginica) performed best when subirrigated and cultured in potting substrate or sand. Golden club (Orontium aquaticum) and lemon bacopa (Bacopa caroliniana) grew best when plants were cultured in potting substrate and maintained under subirrigation. These experiments provide a framework for using existing greenhouses to produce these littoral species and give guidance to growers who wish to produce plants for the restoration market.