Five 12- to 14- month slow release fertilizers (Osmocote 17-7-12, Sierra 16-6-10, High-N 24-4-7, Sierrablend 17-7-10, and Nutricote 16-10-10 Type 360) were incorporated into a 3:1 pine bark: peat moss potting medium at one of 4 rates (0.9, 1.2, 1.5, and 1.8 kg N/m3). Plant growth of 3 azale a species, `Coral Bells' (Kurume), `Formosa' (Southern Indica), and `Pink Gumpo' (Satsuki), and monthly medium solution electrical conductivity (EC) were determined. Growth indices 180 days after applying fertilizer were greatest for plants receiving the Sierrablend and Osmocote fertilizers regardless of azalea species. Plant growth indices increased as N rate increased for the 3 azaleas, regardless of the fertilizer product. The highest media solution EC readings occurred during the first 90 days after fertilizer application for all fertilizer treatments and declined thereafter.