The 2012 ASHS Annual Conference

Eastern redcedar (Juniperus virginana; ERC) has recently proven to be an encouraging avenue for alternative substrate research for nursery crops. To date, several species have been grown in substrates composed partially or entirely of ERC with varying success. The objective of this study was to evaluate the growth of six species in pine bark (PB)- and ERC-based substrates. Three substrates were used (each contained 20% sand):  80% PB, 80% ERC, and 40% PB : 40% ERC (by vol.). On 2 June 2011, individual liners of lacebark elm (Ulmus parifolia ‘Emer II’), compact inkberry holly (Ilex glabra ‘Compacta’), double pink knockout rose (Rosa ‘Radtkopink’), dwarf maiden grass (Miscanthus sinersis ‘Little Kitten’), blanket flower (Gaillardia x grandiflora ‘Goblin’), and autumn joy sedum (Sedum x ‘Autumn Joy’) were planted into each of the three substrates. Plants were grown on an outdoor gravel container pad near Wichita, KS and irrigated by overhead sprinklers (2.54 cm daily). Stem caliper of lacebark elm was greatest in the PB:ERC substrate. Shoot (SDW) and root dry weights (RDW) of lacebark elm grown in ERC were smaller than those grown in PB and PB:ERC at 120 DAP. There were no differences in plant growth index (GI), SDW or RDW of plants grown in any treatment of knockout rose. Sedum plants had greater GI when ERC was part of the substrate. However, maiden grass was generally larger (GI and SDW) when PB was part of the substrate. There were no differences in RDW for sedum. Although inkberry holly RDW was unaffected by substrate, above ground (GI and SDW) were larger when PB was a component of the substrate. There were no differences in GI, SDW or RDW of blanket flower. Plants evaluated in this study were successfully grown in a PB:ERC substrate, thereby expanding the list of species adapted to production in ERC-based nursery crop substrates.