This study aimed to investigate the effect of three soil media, three irrigation intervals, three NPK fertilization rates and their interactions on the growth and development of Conocarpus erectus tree as a new plant to the Egyptian environment. This research was carried out during the two successive seasons of 2004 – 2005 and 2005 – 2006. The obtained results showed significant differences in some investigated characteristics. Clayey soil significantly gave the greatest value of plant height, number of branches per plant but had non significant effect on chlorophyll pigments content. Use of 10 or 15 days irrigation intervals significantly had an effect on plant height, number of branches per plant and chlorophyll pigments content. The addition of NPK at a rate of 5 or 10 gm/plant resulted in significant increase of plant height and number of branches per plant while had non significant effects on chlorophyll pigments content. The interaction treatments showed that generally, clayey medium, 10 or 15 days irrigation intervals and  5 or 10 gm NPK/plant significantly increased the values of plant height while, the mixture medium and 10 or 15 days intervals and mostly 5 gm NPK/ plant  significantly affected the value of number of branches/ plant. Results of interaction showed also that clayey medium with 5 days irrigation intervals and 10 gm NPK/ plant significantly increased the chlorophyll pigments content. Clayey soil irrigated every 15 days and fertilized with 5 gm NPK/plant significantly increased the stem diameter when compared with other treatments. On the other hand, dry matter percentage was significantly increased by the use of mixture medium (clay + sand), 5 days irrigation interval and 10 gm NPK/plant.