Essential Blueberry Fertilization Guide: Nutrients, Schedules, and Best Practices

Wikifarmer

Editorial team

4 min read
02/01/2025
Essential Blueberry Fertilization Guide: Nutrients, Schedules, and Best Practices

A Complete Guide on Blueberry Nutrient Needs and Fertilization

Careful attention to soil pH, organic matter, and balanced nutrient management is crucial for successful plant growth and blueberry production.

It is essential to highlight that no two fields are the same, nor can anyone advise a farmer on fertilization methods without considering the soil test data, tissue analysis, and crop history of a specific field. However, below, some common schemes and fertilization strategies used by many farmers are presented. 

To prevent toxicity, fertilizers should always be applied away from the plant's crown. When designing your fertilization schedule, it is important to follow label instructions and consult a licensed agronomist for site-specific advice. Nutrient application rates and methods should always align with soil and tissue analysis results. For this reason, regular soil analysis is recommended every 2-4 years to test your pH and take necessary actions to keep the soil pH between 4.8-5.2 and the organic matter content above 2-3%. Leaf tissue samples (50 leaves from different plants) should be collected mid-summer. 

Blueberries Nutrient Needs

Nitrogen should be applied in split doses during the growing season. Usually, two applications with nitrogen are needed per growing season: one at flowering (after budbreak) and the other 6 weeks later. This timing coincides with the maximum active nutrient uptake from the plants. 

Farmers usually avoid nitrate fertilizers, while they prefer ammonium sulfate, because it can help maintain a lower pH in the soil. In this case, the farmer can apply 0.2 lb (90 grams) per plant per season (broken down into 2 applications) during the 1st and 2nd years. If the farmer has applied well-rotted manure or compost before planting, fertilization will probably not be needed during the establishment year. If not, you should wait 4-6 weeks after planting before adding any fertilizers. The abovementioned amount will gradually increase, reaching up to 0.6 pounds (300 lb/acre or 336 kg/ha) when the blueberries are fully mature and productive. The N can be added in a single application in heavier soils with low nutrient leaching risk. If you use a mulch of wood chips or sawdust, add an extra 0.1 lb (45.4 grams) of ammonium sulfate per plant for the first few years. If the pH of the soil is already low enough, it is best to use urea as the main nitrogen source. 

Besides nitrogen, phosphorus and potassium are also essential nutrients needed for good blueberry growth and yield. More specifically, phosphorus is necessary for root development, and potassium is necessary for fruiting and plant health. In soils with a P (phosphorus) or/and K (potassium) deficiency, farmers can apply annual 25-50lb P2O5 and/or 50-75 lb K2O per acre (28-56 kg/ha P2O5, 56-84 kg/ha K2O), respectively. Potassium sulfate is preferred over chloride forms.

In most cases, farmers prefer to apply complex synthetic fertilizers. In general, controlled-release fertilizers are preferred for basic application since they provide a steady nutrient supply for longer periods, reducing at the same time the risk of nutrient losses. Some common examples are the 10-10-10, 10-5-5, or 7-0-7 (N-P-K), depending on the soil's needs. When a 10-10-10 fertilizer is used, you can add 10 oz to 1 lb per 100 feet row (0.28-0.45 kg per 30 m row) 4 weeks after planting. If there is a need for simultaneous fertilization for nitrogen and phosphorus (only), the farmer can use monoammonium phosphate (MAP) (11-52-0) and di-ammonium-phosphate (DAP) (16-48-0).

Nutrient limits for blueberry plant tissue

The plants are considered N deficient when the leaf N is below 1.7%, while levels higher than 2.3% could be an indication of over-fertilization. Adjust the fertilization accordingly. 

Besides the 3 primary nutrients (N-P-K), blueberries also need Mg, Fe, Mn, Cu, Mo, and B. If iron chlorosis starts developing, you can directly control it by spraying the foliage with chelated iron fertilizer. However, this is only a temporary solution, and the deficiency should be resolved with soil application over time. Deficiencies of potassium or most of the micronutrients are generally rare. 

Always consult your local agronomist before applying any fertilizers.

References

Further reading

14 Interesting Facts about Blueberries

Uses, Nutritional value and Health Benefits of Blueberries

Blueberries vs. Bilberries- Are blueberries and bilberries the same thing?

Blueberry Plant Information-How to Identify Blueberry Plants

Blueberry Soil Conditions and Site Selection

How to Cultivate Blueberries Professionally

Blueberries Propagation and Pollination

Blueberry Water Needs and Irrigation Methods

Essential Blueberry Fertilization Guide: Nutrients, Schedules, and Best Practices

How to Prune Blueberries

Blueberries Pests, Diseases, and Weed Management

Blueberries Harvest, Yield, and Storage