Broschat, T.K., D.R. Sandrock, M.L. Elliott and E.F. Gilman
Effects of fertilizer type on quality and nutrient content of established landscape plants in Florida

HortTechnology 18 (2): 278-285

In a series of three experiments, st. augustinegrass (Stenotaphrum secundatum 'Floratam'), areca palm (Dypsis lutescens), canna (Canna x generalis 'Richard Wallace'), pentas (Pentas lanceolata), allamanda (Allamanda cathartica 'Hendersoni'), and nandina (Nandina domestica) were grown on highly leached sand soils in two locations in Florida. They were fertilized with typical turfgrass fertilizers having high nitrogen (N)-to-potassium (K) ratios and no magnesium (Mg), or several types of landscape palm fertilizers having low N:K ratios and 100% of their N, K, and Mg in controlled release form. St. augustinegrass, pentas, nandina, and allamanda visual quality were similar for all fertilizer types tested. However, cannas and areca palms had higher visual qualities when fertilized with an 8N–0.9P–10.0K–4Mg palm fertilizer than with higher N:K ratio turf fertilizers. High N:K turf fertilizers resulted in K deficiency severity equivalent to that of unfertilized controls and Mg deficiency that was more severe than unfertilized areca palms.

Click here for full article (PDF file)