The NPK 10-10-10 fertilizer is a type of shrub and tree fertilizer that also contains 3 essential nutrients: nitrogen (N), phosphorus (P) and potassium (K). The numbers in the ratio represent the percentage of each nutrient contained in the fertilizer, in the order of N-P-K. The NPK 10-10-10 ratio indicates a balanced fertilizer formulation, with equal proportions of nitrogen, phosphorus and potassium. This balanced ratio is suitable for providing general nutrient support to shrubs and trees, promoting overall growth and maintaining plant health. However, it is important to consider specific plant species, soil conditions and any additional nutritional requirements when determining the appropriate application rate for optimal results.