David Himelrick, Attaway, Denise | 6/17/2011 1:49:01 AM
Blueberries require a lower pH than many other fruit and vegetable crops. Before planting blueberries, test the soil to determine the pH and amounts of nitrogen, phosphorus, potassium and organic matter present. You can find out what your soil pH is by taking a sample to your parish extension office. Blueberries require a soil pH of 4.0 to 5.3 for best growth. The primary material recommended for lowering soil pH is finely ground wettable sulfur. Since sulfur reacts slowly and must be converted by soil bacteria, the change in soil pH is brought about slowly. Therefore, sulfur should be added to the soil and mixed thoroughly several months to a year prior to planting.
The amount of sulfur to use for lowering the pH of the various soil types is given in Table 1. If your soil pH is in the range of 5.4 to 6.0, sulfur can be applied six months before planting to lower the pH. Sulfur also can be applied after planting to the soil surface but not mixed with the soil. Rates of up to 7/10 pound per 100 square feet can be used yearly, if needed.
If the initial soil pH is above 6.0, growing blueberries will be difficult unless massive amounts of peat moss or milled pine bark are mixed with the soil. Use 1 pound (2.5 cups) per 100 square feet on sandy soils to lower pH by 1 unit (for instance, from 6.0 to 5.0). Apply 2 pounds per 100 square feet for the same amount of pH lowering on heavier soils containing silt, clay or more than 2 percent organic matter. Try to achieve a pH of around 4.8; too much reduction can be detrimental to bush growth.
Organic matter additions
Because Louisiana soils typically have a low organic matter content, incorporating peat moss or well-decayed pine sawdust or bark will improve plant survival and growth. Apply 3 to 4 inches of the organic material over the row in a band 18 to 24 inches wide and incorporate thoroughly using a rototiller or spade to a depth of 6 to 8 inches. For small plantings, the soil structure may be improved by the incorporation of organic materials such as peat, pine bark or leaf mold into the soil. Heavy soils require larger quantities than do lighter soils and are more difficult to maintain. Mix 2 to 5 gallons of wet peat moss or milled pine bark with the soil in each planting hole. Do not use any agriculture lime; blueberries require an acid soil.
Adequate soil drainage is essential. Blueberry plants will not tolerate excessive moisture (wet feet) for long periods. In low, poorly drained areas, set plants on raised beds 6 to 12 inches high and 4 feet wide. Arrange elevated rows to allow good drainage from between rows.
Supplemental irrigation is essential in most seasons, and, on most soils, plants should be watered throughout the growing season when rainfall is inadequate. Irrigation of young plants is especially important. Adequate water is essential for plant growth and is important for fruit bud formation that occurs in fall. Hand watering with a hose is possible for several bushes; however, a soaker hose will usually give more uniform wetting. In larger plantings, systems using microsprinklers have been more successful than point-source drippers. Even two drippers per plant often do not wet enough of the soil in the root zone. At least 50 percent of the area under the drip line should be wetted. The use of automatic timers on drip or microsprinkler irrigation systems can result in shallow root systems and root rotting if systems apply water daily. Apply irrigation no more than once every two days to reduce the chances of root rot infection.
Himelrick, David. Home Blueberry Production in Louisiana. Retrieved 16 June 2011.