General Fertilizer Information
There are 3 main macronutrients that you’ll see on every bag or box of fertilizer; Nitrogen (N), Phosphorus (P), and Potassium (K) - NPK.
Nitrogen is largely responsible for foliage growth because its the main part of photosynthesis and the green color we see in leaves. Therefore, yellow leaves can be associated with lack of nitrogen.
Phosphorus helps root growth as well as flowers and fruits, and Potassium helps the overall function of the tree and supports the plants vitality as well as ability to fight infections. The numbers shown, for example 8-4-4, represent the percentages of said nutrients that are available in the fertilizer. 8% Nitrogen, 4% Phosphorus and 4% Potassium.
Phosphorus and Potassium mainly help with flower and fruit development, therefore providing a fertilizer formulated with more phosphorus and potassium than nitrogen, prior to the plant flowering, can increase yields.
There are also 7 essential plant nutrients known as micronutrients; Boron (B), Zinc (Zn), Manganese (Mn), Iron (Fe), Calcium (Ca), Magnesium (Mg), Copper (Cu), Molybdenum (Mo), and Chlorine (Cl). They make up less than 1% of the total dry weight of plants, but are also vitally important to the trees overall health.
When to Fertilize
Spring is the most important time to fertilize. Apply a fertilizer with more nitrogen to promote growth.
Our 8-4-4 is an example of a complete fertilizer with more nitrogen to promote growth and fruit production. Apply every 3 months. spring through fall, starting in March.
Apply our 3-12-12 Harvest Booster in the winter for deciduous trees to promote spring blossoms. Supplement our Harvest Booster in the spring for Citrus Trees.
If you’re noticing any more deficiencies, even after fertilizing, you may need to put in additional micro-nutrients like Magnesium, Calcium and Iron. Keep in mind that your fertilizing schedule will depend on your tree's seasonal cycle more than anything.
How Much Fertilizer To Use
- Apply 1 cup (150 grams) for every 1” of diameter of the trunk or 15 gallon size.
- Apply 2 cups (300 grams) for every 2’ diameter of trunk or 25 gallon size.
Maintain that 1:1 ratio as the tree(s) mature.