Effects of peat moss substitution with arboretum and greenhouse waste compost for use in container media
Plugs of impatiens (Impatiens walleriana Hook.f.), salvia (Salvia splendens Sellow ex Roem. & Schult.), and vinca (Catharanthus roseus (L.) G. Don) were transplanted into containers filled with commercial Sphagnum peat moss plus perlite medium (Sunshine Mix #1) or arboretum and greenhouse waste compost (CT), Sphagnum peat moss (PS), and perlite (PE) medium at percentages of (by vol.) 50:50 PS:PE and 75:25 PS:PE (controls). CT media included 25:50:25, 25:25:50, and 50:25:25 CT:PS:PE, or 50:50 and 75:25 CT:PE. Shoot dry weight of vinca and impatiens and stem diameter of vinca were greater for 25:50:25 CT:PS:PE than controls. Shoot dry weight and stem diameter of salvia were similar for CT media and controls. CT additions increased bulk density but decreased particle sizes, total porosity, and container capacity. It was concluded that CT-growing methodology could be implemented without loss of plant quality, although physical media characteristics limit the amount of compost and component ranges within container media.