Complex fertilizers are mixtures of simple fertilizers that are formulated to give a wide array of N-P-K numbers. Complete fertilizers contain all 3 N-P-K numbers and tend to cost more than simple fertilizers. Artistic Arborist offers a large selection of Grow More brand fertilizers to treat all garden and tree care situations. We offer fertilizers that have slow vs. quick release properties, those that are better for foliar vs. soil applications, those for alkaline soils those with high or low potassium and phosphorous etc. Their properties and uses are outlined in tables grouped according to nitrogen content. We have very high nitrogen (above 30%), high nitrogen (20-30%), medium nitrogen (10-20%) and low nitrogen (below 10%). The tables describe the fertilizer, the % nitrate-, ammonium-, urea- and water insoluble- N