Abstract
Dwarf Japanese euonymus (Euonymus japonica Thunb. ‘Microphylla’) and Japanese holly (Ilex crenata Thunb. ‘Compacta’), grown in fresh or aged (1 year) pine bark amended with a slow-release complete fertilizer, were supplied with NH4NO3 weekly at 0, 100, 200, or 300 ppm N. Plant growth, foliar color, leaf tissue N, and leachate soluble salts increased with increasing levels of supplemental N while tissue K, Ca, and Mg decreased. Plant growth, foliar color, and leaf tissue N, P, Ca, and Mg in fresh pine bark equaled or exceeded that in aged pine bark at all levels of supplemental N. Leachate soluble salts, pH, and leaf tissue K was higher in aged pine bark.