The Best Time of Year to Fertilize Trees: A Seasonal Guide

Fertilizing trees at the right time of year can dramatically impact their health, growth, and resilience. Using the right tree fertilizer—applied in the proper season—ensures trees receive the nutrients they need exactly when they need them. In this guide, we explore seasonal strategies for applying tree fertilizer, while integrating effective solutions like YaraFert products to maximize results.


Why Tree Fertilizer Timing Matters for Growth

Tree growth follows seasonal cycles, and understanding these biological rhythms is critical to fertilization success. Applying tree fertilizer at optimal times improves:

  • Root development
  • Leaf and canopy density
  • Fruit and flower production
  • Resistance to pests, drought, and temperature stress

Applying nutrients out of sync with these cycles may lead to leaching, root burn, or ineffective uptake. For instance, nitrogen-heavy formulas like Ugarit 40-10-10 + TE are best used during active growth periods to support leaf development and photosynthesis.


Applying Tree Fertilizer in Spring: What to Know

Spring is typically the most effective time to fertilize trees. As temperatures warm and sap begins to flow, trees enter a phase of rapid growth. Fertilization at this stage enhances bud break and shoot elongation.

Consider these spring fertilization tips:

  • Use a balanced NPK formula such as Ugarit 27-27-27 + TE to support root, shoot, and flower development.
  • Apply granular or slow-release tree fertilizer like Ugarit 10-0-5 + 70% Organic Matter for sustained support.
  • Prioritize micronutrient-rich suspensions such as SULFOMIX, containing zinc, magnesium, boron, and iron to promote chlorophyll synthesis and metabolic efficiency.

Ideal Spring Tree Fertilizers:


Summer Use of Tree Fertilizer: Myths and Facts

There’s a common belief that summer fertilization harms trees. While mid-summer heat may reduce uptake efficiency, certain cases justify nutrient application.

When summer fertilization is beneficial:

  • Trees showing chlorosis or nutrient deficiency symptoms
  • Fruit or nut trees in active fruiting stages
  • Recovery from environmental stress like drought or pruning

Use low-nitrogen, potassium-rich products such as:

  • Ugarit K-T-S 70: 36% K2O and 70% SO3 for fruit finish and stress resilience
  • Ugarit Multi: Potassium, sulfur, and calcium to support cell wall strength and drought tolerance
  • Sulforex 60 + Cu: Delivers mineral sulfur and copper to bolster disease resistance

Avoid: Excessive nitrogen in high heat, which can burn roots and promote weak shoot growth.

READ MORE: How Tree Fertilizer Works: Understanding Nutrient Needs for Trees


Fall Tree Fertilizer Applications and Root Prep

In autumn, trees shift their energy to root development and carbohydrate storage. Fall fertilization should avoid stimulating new foliage and instead focus on:

  • Strengthening roots
  • Enhancing winter hardiness
  • Replenishing soil micronutrients

Recommended fall fertilizers include:

  • Ugarit 0-5-65: High potassium for root growth and disease resistance
  • Ugarit DKP: 33% phosphorus and 44% potassium to support late-season energy storage
  • SULPHOMIN: Nitrogen with sulfur and organic matter to maintain root metabolism

Tips for Fall Application:

  • Apply after leaf drop but before the ground freezes
  • Water deeply post-application to help nutrient absorption

Is Tree Fertilizer Effective During Winter Months?

While winter is largely a dormant period, certain soil treatments can still offer value. In milder climates, root systems remain somewhat active and can benefit from dormant-season nutrition.

Winter fertilization may be appropriate if:

  • The soil test shows deficiencies
  • You’re preparing newly planted trees
  • You apply slow-release or organic formulas that will activate come spring

Winter-friendly tree fertilizers include:

Avoid applying water-soluble nitrogen in winter unless using controlled-release forms.


Summary: Seasonal Tree Fertilizer Guidelines

To guide your seasonal strategy, here’s a quick reference of when and how to use tree fertilizer effectively:

SeasonFertilizer FocusRecommended YaraFert Products
SpringShoot/root growth, leafingBiofast, Ugarit 27-27-27 + TE, SULFOMIX
SummerFruit development, stress toleranceUgarit K-T-S 70, Ugarit Multi, Sulforex 60 + Cu
FallRoot energy storage, winter prepUgarit DKP, Ugarit 0-5-65, SULPHOMIN
WinterSoil conditioning, pre-spring feedPhosphoric Acid 85%, Ugarit 10-65-10, Ugarit Beet

Final thoughts

For optimal tree health, choosing the right tree fertilizer and applying it at the right time of year is essential. Whether you’re supporting spring bud break, boosting summer fruit production, or preparing roots for winter, Yarafert solutions deliver proven, scientifically balanced formulations.

Visit our website to explore the complete range of Yarafert fertilizers or contact our agronomy team for expert guidance on seasonal fertilization plans tailored to your crops and conditions.

READ MORE: A Beginner’s Guide to Choosing the Right Tree Fertilizer



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