Evaluation of Eastern Redcedar Substrate in the Production of Four Annual Species

Abstract

Peat moss and perlite have been major components in greenhouse substrates for over 50 years; however, shortages could occur due to restrictions from environmental concerns, fuel cost, and weather conditions. Due to these factors, research continues to seek available materials as alternative substrate components. These studies evaluated processed eastern redcedar (Juniperus virginiana L.) as an alternative substrate in the greenhouse production of four annual species: petunia (Petunia ×hybrida Juss.), annual vinca [Catharantus roseus (L.) G. Don], wax begonia (Begonia semperflorens-cultorum Hort.), and plumed cockscomb (Celosia argentea L.). Three screen sizes of hammer-milled eastern redcedar (ERC) were used including 0.64, 0.95, and 1.27 cm (0.25, 0.38, and 0.5 in). Plants were grown in peat moss amended with either 25 or 50% ERC (combinations of three screen sizes) and compared to a standard 80:20 peat:perlite mix. Plant growth was similar for petunia and vinca in 50% ERC (1.27 cm screen size) compared to those grown in 80:20 peat:perlite. Plants grown in 25% ERC were similar to plants grown in 80:20 peat:perlite mix for all species in all screen sizes. Root growth was similar to or greater for plants in substrates with 25% ERC when compared to the standard peat:perlite treatment. Amending peat with up to 25% eastern redcedar is an acceptable practice for the four annual species used in this study.