The pluses and minuses of using time-release
Time-release fertilizers are excellent to use at planting time. Follow the manufacturer's directions carefully as to the size of the plant to be fed and the exposure to sunlight.
For plants with limited nutrient needs, time-release fertilizers may be enough to support the plant throughout it's life. For others, subsequent applications of liquid fertilizers throughout the growing season may still be needed.
Keep in mind that time-release fertilizers do not work in cold soils (a soil temperature of more than 40 F is necessary), and tend to break down quickly when soil temperatures rise into the 80's. Also, if a time-release fertilizer is used after initial planting, it must be mixed very well into the soil, never sprinkled over the surface.