Growing Guides: Fertilize Citrus trees

To encourage flowering and fruiting in your 6-year-old citrus trees, you need to focus on fertilizers and amendments that provide essential nutrients while maintaining a healthy soil environment. Here's a guide:

Key Nutrients and Amendments:

1. Nitrogen (N):
   • Promotes vegetative growth, which supports flowering and fruiting.
   • Use a slow-release nitrogen fertilizer, such as ammonium sulfate or organic options like blood meal.
   • Avoid excessive nitrogen as it can promote leafy growth at the expense of flowers and fruit.
2. Phosphorus (P):
   • Crucial for flower and fruit development.
   • Apply bone meal or a phosphorus-rich fertilizer like superphosphate in the trough.
3. Potassium (K):
   • Enhances fruit quality and helps trees withstand stress.
   • Use potash or organic sources like sulfate of potash or kelp meal.
4. Calcium (Ca):
   • Prevents blossom end rot and promotes overall health.
   • Add dolomite lime or gypsum, depending on your soil pH (dolomite if the soil is acidic).
5. Magnesium (Mg):
   • Essential for chlorophyll and photosynthesis.
   • Use Epsom salt (magnesium sulfate); sprinkle around the trough and water in.
6. Micronutrients:
   • Zinc (Zn), manganese (Mn), and iron (Fe) are important for enzyme functions and growth.
   • Apply a citrus-specific micronutrient mix or use chelated versions of these minerals.
7. Organic Matter:
   • Improves soil structure, moisture retention, and nutrient availability.
   • Add well-aged compost or manure to enrich the soil.
8. Mulch:
   • Retains moisture, moderates soil temperature, and reduces weeds.
   • Use organic mulch like bark chips, straw, or grass clippings, keeping it a few inches away from the trunk.

Application Instructions:

1. Create the Trough:
   • Ensure the trough is about 2 inches deep and 12-18 inches wide, following the tree’s canopy edge (drip line).
2. Apply Fertilizers:
   • Use a balanced citrus fertilizer with an NPK ratio of around 3:1:2 (e.g., 12-4-8).
   • Follow package instructions for the amount based on tree size and age.
3. Incorporate Organic Matter:
   • Mix compost or well-aged manure into the soil within the trough.
4. Apply Micronutrients:
   • Spray a liquid micronutrient solution or spread granules evenly in the trough.
5. Water Thoroughly:
   • After applying the fertilizers and amendments, water the trough deeply to ensure nutrients reach the root zone.
6. Timing:
   • Spring: Before flowering begins.
   • Mid-Summer: For continued growth and fruit development.
   • Avoid late-fall fertilization to prevent frost-sensitive new growth.

Additional Tips:

• Soil Testing: Check the pH and nutrient levels of your soil to adjust amendments. Citrus trees prefer slightly acidic soil (pH 6.0-7.0).
• Water Management: Maintain consistent moisture but avoid overwatering, which can lead to root rot.
• Pruning: Remove dead or crossing branches to focus energy on productive growth.

By ensuring the right balance of nutrients and care, your citrus trees will be well-positioned to produce abundant flowers and fruit.