Blueberry Water Needs and Irrigation Methods

Wikifarmer

Editorial team

4 min read
02/01/2025
Blueberry Water Needs and Irrigation Methods

How much water does a blueberry need, and when to irrigate

Due to the shallow (less than 18 in or  46 cm deep) and fibrous root system, blueberries need a regular water supply, especially when grown in sandy soils, to produce fruits. Blueberry plants need at least 16-50 mm (on average 25-40 mm) of water per week during the growing season. More specifically, during the warmest months of the year, the daily water use of mature blueberry plants reaches 4.3-18 L (1.13-4.8 gallons) per day, while during winter (dormancy), decreases to 0.8-1.5 L (or 0.2-0.4 gallons) per day. The farmer should add the average soil evaporation due to high temperatures at these numbers to form the irrigation schedule. The grower should compensate with irrigation when rainfall is insufficient. It is advised to apply 35-50 L (9.2-13 gallons) of water per plant per week through irrigation. This amount is best applied in 3 doses to ensure optimum plant performance. To increase efficiency, you have to:

  1. Monitor the soil moisture content with specialized sensors like tensiometers.
  2. Allow the soil at the root zone to dry to 30-50 centibars of water tension between irrigations.
  3. Avoid irrigating more often than twice a week to decrease the risk of bad drainage and root rot, as well as prolonged drought periods that can severely stress the plants.

An especially critical period with high plant water needs is the time a little before and during floral initiation. Lack of water during this stage will result in wilting and dieback of tender shoots and decreased fruit yield. Additionally, the soil moisture should be conserved at appropriate levels even after harvest to help the floral initiation for the following season before the plants enter the dormancy period.  

How to irrigate blueberries 

Choosing an irrigation method tailored to the blueberry’s needs can significantly improve water use efficiency while protecting crop health. 

Drip irrigation: 

This is the most commonly used method, offering precise water delivery to the root zone while minimizing waste. Each plant requires at least two drippers, each releasing 1–2 gallons of water per hour. Applying 76 liters (20 gallons) of water per day per 30-meter row for young plants ensures even moisture distribution. Drip systems are compatible with fertigation, allowing nutrients to be delivered alongside water.

Micro-sprinklers and Overhead Sprinklers:

 

However, in very large plantations, micro-sprinklers and overhead sprinklers with high output (about 10 gallons per hour) may be preferred for efficiency. Micro-sprinklers offer uniform water distribution and are effective for sandy soils. They work at lower pressures, reducing evaporation losses compared to overhead sprinklers.

Remember to adjust the duration and amounts of irrigation, considering that around 20-30% of the water from overhead sprinklers may be lost. Sprinkler irrigation is one of the most efficient frost-preventive measures. A system with 12 sprinklers per acre (60*60 feet or 18*18 m) is appropriate. The farmer should activate them when:

  • the temperature drops to 33-34 °F (0.5-1 °C) if the relative humidity (RH) is high (close to 100%), 
  • and at 37 °F (3 °C) in more dry weather (40% RH).

Irrigation of Blueberries.jpg

 

Furrow irrigation:

For smaller farms or regions with abundant water supplies, furrow irrigation remains a viable choice, although it is less efficient due to runoff and evaporation. This method involves channeling water through shallow trenches between rows of plants. 

Key Practices for Efficient Irrigation

  • Irrigate no more than twice weekly to balance moisture retention and drainage.
  • Monitor soil moisture levels to prevent overwatering or underwatering. To optimize irrigation, growers should monitor soil moisture levels, keeping them between 50% and 75% of field capacity using tools like tensiometers. 
  • Use irrigation water of acceptable quality; blueberries are sensitive to high soil salinity.
  • During critical growth periods, you need to ensure a consistent water supply to avoid yield loss and plant stress.
  • Maintaining post-harvest soil moisture to support the next season's floral initiation is essential.
  • Applying organic mulch around the plants in a 3-4 feet wide band (around 1 m) will help prevent excessive water evaporation, preserve soil moisture, and increase the efficiency of irrigation. Good organic mulch can be wood chips, bark, leaves, shavings, or pine needles, although the latter can acidify the soil over time and is more difficult to find. If possible, avoid sawdust because it tends to compress the soil over time and obstruct the water from reaching the roots. 

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