Composted green waste as a container medium amendment for the production of ornamental plants

Abstract

Seed germination and crop growth characteristics were determined for Tagetes spp. L. 'Lemondrop', marigold; Catharanthus roseus Don. 'Little Pinkie', vinca; Petunia hybrida Vilm. 'Royalty Cherry', petunia; Dendranthema x grandiflorum (Ramat.) Kitamura 'White Diamond', chrysanthemum; Pittosporum tobira Ait. 'Wheeleri', sweet mock orange; Photinia x fraseri Dress., photinia and Juniperus sabina L. 'Moon Glow', juniper grown in various size containers containing blends of composted green waste (CGW) and UC Mix. Seed germination, plant height, and stem and root fresh and dry mass were lowest in unamended CGW. For most plants studied, a CGW: UC Mix blend containing at least 25% UC Mix was required for adequate growth and development. Germinating seeds and young seedlings were most adversely affected by unamended CGW. As plants grew and were transplanted into larger containers (10- and 15-cm pots, 530 and 1800 mL), they were better able to grow in media with higher CGW content.