Production and Landscape Establishment of Nursery Crops in Eastern Redcedar-Amended Substrates

Abstract

Substrate material used for the purpose of growing ornamental plants in the Great Plains is generally shipped a significant distance, primarily from the Southeastern United States. Eastern redcedar (Juniperus virginiana; ERC) chips have been identified as a possible alternative to pine bark (PB) for nursery substrates. Landscape establishment of Ulmus parvifolia ‘Emer II’ (elm), Rosa ‘Radtkopink’ (rose), Ilex glabra ‘Compacta’ (holly), Miscanthus sinensis ‘Little Kitten’ (maiden grass), Gaillardia ×grandiflora (blanket flower), Sedum ‘Autumn Fire’ (sedum), Hosta ‘Sum and Substance’ (hosta), and Hemerocallis ‘Charles Johnston’ (daylily) plants were grown in three substrate mixes. Substrate mixes were composed of 80:20 PB:sand (PBS), 40:40:20 PB:ERC:sand (PBERCS) or 80:20 ERC:sand (ERCS) (by vol). The study was split into production and landscape phases. During the production phase, pH and EC were among the parameters measured. For both phases of the study, growth index (GI), SPAD, caliper and shoot- and root dry weight were measured. At the end of the production phase, differences in growth were observed in elm, holly, and maiden grass where substrates containing PB or a mixture of PB:ERC resulted in greater growth over a primarily ERC-based substrate. Sedum also exhibited growth differences, with plants growing larger in ERCS as a production substrate. At the conclusion of the landscape establishment phase, there were no observed differences in growth for tested species with the exception of holly and hosta which grew best if produced in PBS and/or PBERCS prior to transplanting based on shoot- and root dry weights as well as GI on most evaluation dates. The majority of species in this study overcame any growth shortages present at the end of production within the first growing season in the landscape. Therefore, ERC is a viable substrate option for producing and planting many nursery crops, though it is advisable for each nursery to evaluate their particular crops for production in alternative substrates.