Mangos, also known by their scientific name Mangifera indica, are a commercial fruit popular for harvest in tropical and subtropical plants. They can also be grown as decorative plants in home landscapes. They require high nitrogen fertilizers with a balanced amount of micronutrients to support fruit production requirements throughout the year.
Mango trees require high levels of nitrogen to support their fruit production. The rule of thumb for these trees is to apply 1/2 cup of 21-0-0 fertilizer each month after planting until early September for the first year. In the following spring, increase this amount to 1 cup per month until September and finally 2 cups for the third year. This mixture will provide the tree with a boost of nitrogen for strong root systems to help build a strong foundation during the early years of the mango tree's growth. Fully grown trees should get fed at a ratio of 2 cups per inch of trunk diameter during the months of February, May and August each year.
Newly Planted Mangos
For more specific instructions on the growth of mango trees at home, you need to first know the tree's age and the soil conditions of the plant. Young trees between the ages of 1 and 3 require NPK mixes of 6-6-6 or 8-3-9 six times spread out evenly throughout the year. Three pounds of fertilizer is required for first-year trees, up to 6 lbs. the second year and 9 lbs. the third year.
Trees older than 4 years, with nutrient-retaining soil, should be given the 8-3-9 mixture of NPK fertilizer. While the amount of food given per feeding is increased as the tree ages by increments of 3 lbs. per year, it shouldn't be fed more than four times per year between the months of March and August. Trees 4 years old need at least 9 lbs. of fertilizer, 12 lbs. for trees 5 years old, 15 lbs. for 6-year-old trees, and the amounts continue to grow from there.
Organic fertilizers provide nutrition for trees in a slightly alternative way than traditional fertilizers. Since they are typically filled with higher levels of micronutrients, trees should be given fertilizers with an NPK of 4-4-8 throughout their life span, applied only once a year at 1/4 cup per foot of tree height. Never misuse organic fertilizers when feeding plants, as this may cause contamination of the soil and endanger local vegetation, including the mango tree itself.
Mango trees growing in alkaline soils can use spray fertilizers to feed them the micronutrients they require each year. The product will have specific instructions on the application of the spray, but gardeners can use "applications six times a year for young trees and four times a year for mature ones" as a rule of thumb, according to Christopher Brickell, in his book "Growing Fruit: RHS Encyclopedia of Practical Gardening."