Physical Properties of Pine Bark and Hardwood Bark Media and Their Effects with 4 Fertilizers on Growth of llex x ‘Nellie R. Stevens’ Holly

Abstract

Pine bark (PB) and composted hardwood bark (HWB) were combined into 5 media. Particle size distribution, total porosity, air space, moisture retention characteristics, and bulk density were determined for each medium. Four commercial fertilizers were applied and substrate nitrogen levels, pH, % foliar nitrogen and top dry weight were determined for Ilex x ‘Nellie R. Stevens’ holly. Pine bark had approximately 84% of the particles between 4.75 and 1.0 mm (0.19 and 0.04 in). As HWB was added in 25% increments (by vol) the percent weight of particles in this range decreased. HWB increased bulk density, but did not significantly change total porosity. Hardwood bark and the 1:3 PB:HWB (v/v) medium held more water than other media. Nursery Special raised pH in all media treatments. Plants treated with SulfurKote tended to have the highest foliar nitrogen content. The Sierrablen in PB and SulfurKote in 3 PB:1 HWB and 1 PB:1 HWB (v/v) and HWB produced the greatest top dry weight.