Fertilize Plumeria every 2-4 weeks during its active growing season. The frequency of fertilization depends on the type of fertilizer used and the growth rate of the plant. Slow-release fertilizers release nutrients gradually and require less frequent applications, typically every 4 weeks. Fast-release or liquid fertilizers may require more frequent applications, such as every 2 weeks. Avoid over-fertilizing, as excessive nutrients can lead to salt buildup in the soil, causing root damage and other issues. Always follow the manufacturer’s instructions for the specific fertilizer being used.