2026 Citrus Bloom: Focus on Nutrition

This week, citrus bloom has been declared in most of Fresno, Tulare and Kern counties. It’s time to start preparing your plants and your soil for the most important stage of the growth cycle.

This year, we’re encouraging our growers to focus on nutrition. If properly applied ahead of bloom, it plays a crucial role in flower strength, pollen viability, and fruit development. Working with Robert Fahey, an independent PCA with a heavy nutritional background, we’ve put together the following list of recommendations to help influence your fruit set, retention, and overall yield potential. After all, as Fahey points, “a healthy orchard starts with a well-balanced nutritional program.”

SOIL-APPLIED NUTRITION

The goal is to build a balanced soil foundation before bloom, without stimulating an unwanted flush. To do this, use nutrients like the following:

Nitrogen (N)

• • Apply at moderate rates, 3–5 weeks prior to bloom.
  • Avoid creating an excessive vegetative push, which will redirect energy away from your flowers.
  • Use efficient nitrogen sources that perform in cool soil conditions, like calcium ammonium nitrate or ammonium sulfate.

Phosphorus (P)

• • Critical for ATP production and flower energy.
  • Phosphorous availability is low in cold soils, so utilize available P sources when soil temperatures are cool. These include liquid fish emulsion fertilizers, well-composed manure, and bone meal.
  • Ensure strong root activity heading into bloom.

Potassium (K)

• • Supports osmotic balance, early fruit sizing, and stress resistance. Also improves bloom strength and retention.
  • K is needed throughout the season, but be sure to time your applications early to encourage strong root growth. Apply again during the fruit development and ripening phases.
  • Monitor K:Ca ratios to avoid imbalances, especially during the fruit cell division window.

Calcium (Ca)

• • Essential for cell wall development in young fruit.
  • Important in high sodium or tight soil conditions with high clay levels.

PRECISE FOLIAR APPLICATION

Foliar nutrition will help ensure important micronutrients are immediately available during flower development. 10 to 21 days before bloom, focus on the following nutrients for targeted bloom support:

Boron (B)

• • Critical for pollen tube growth and fruit set.
  • Avoid over-application by using safe, low rates (0.5-1 lb/100 gal).

Zinc (Zn)

• • Supports hormone balance and bloom uniformity.
  • Chelated forms preferred for uptake.

Manganese (Mn)

• • Supports photosynthesis and enzyme activation.
  • Foliar sprays are important in high pH soils, where soil applications can be ineffective. Apply when new leaves are 2/3 expanded in the spring or summer.

Low-Biuret Urea

• • Enhances bloom intensity when applied between December and February.
  • Improves micronutrient uptake efficiency.
  • Supports carbohydrate movement into developing flowers.

Optional: Biostimulant Support

• • Seaweed or cytokinin-based products may enhance stress tolerance and bloom synchronization.

TIMING OVERVIEW

At Fruit Growers Supply, we want to help you enjoy a strong, uniform bloom with improved fruit set, optimized fruit sizing, and increased pack-out potential. Call us today or visit a supply store to talk about customized nutrition programs tailored to your ranch.