Site selection is crucial to the success of a blueberry planting. Soil properties (including fertility and terrain), climatic factors, and irrigation water quality must be considered when evaluating a site. Blueberries grow best in well-drained sandy soils with a pH of 4.5 to 5.5. Plants growing in soils with an improper pH will grow poorly, exhibit symptoms of nutritional deficiencies, and experience considerable mortality during plant establishment. As a general rule, blueberries grow best on non-agricultural land that has been recently cleared. Old pasture sites or old farmland with a pH below 5.5 may be well-adapted to blueberry culture.
If you are considering a particular location to establish a blueberry planting, your first step should be to conduct a simple soil test, or bring a soil sample to your local soil testing laboratory. Blueberry producers growing traditional blueberry crops can get a listing of soil testing laboratories from the American Horticulture Society, and producers growing organic crops can get a comprehensive list of alternative soil testing laboratories from the National Sustainable Agriculture Information Service (ATTRA). There are several guidelines to follow when choosing a soil testing laboratory including: test methods, laboratory proficiency, units of results and so on. The Ohio State University Cooperative Extension Service lists other guidelines in its Guidelines for Choosing a Soil Analytical Laboratory.
Follow soil test recommendations to correct any inadequacies, eliminate hardpans, improve soil structure and adjust organic matter to acceptable levels for your particular blueberry varieties. Blueberry plants will perform poorly in areas with large amounts of wood ash. This may occur in sights where windrows, rows of vegetative debris, were recently burned or on newly cleared land. These areas have high concentrations of minerals, salts and a high pH level. The location of these windrows should be considered when laying out the field to reduce problem areas after planting.
Soil tests could save blueberry producers money. According to a report, Why Soil Tests are Important, from the United States Department of Agriculture, people could save as much as $100 per acre by spending a few dollars on soil tests.
Soils with a native pH above 5.5 will be hard to modify for blueberry culture and should be avoided. The pH of soils with low native pH that has been limed to achieve an artificially high pH may be lowered by adding sulfur. The sulfur should be incorporated into the soil at least six months before planting. More information on soil pH can be found in Soil pH and Fertilizers from the Mississippi State Universtiy Cooperative Extension Service.
Blueberries have a shallow, fibrous root system that grows best in a well-drained soil with high organic matter content. High soil organic matter will increase plant vigor and fruit production of blueberry plants. The addition of organic matter, such as pine bark, to the soil at planting will greatly increase the productivity of the blueberry planting.
Weed control is especially important because blueberries are very poor competitors for moisture and nutrients. Clean cultivation can be used, but care must be taken to avoid injury to the very shallow root systems of these plants. Use of sod strips between rows, with maintenance of a weed-free strip 3 to 4 feet wide on row centers, is preferable.
It is essential that a weed-free strip be maintained in the rows to ensure that weeds do not compete with the blueberry plants. This is best accomplished by appropriately timed applications of preemergence and postemergence herbicides. Hand hoeing and shallow mechanical cultivation may also be used in some instances. The proper time to apply preemergence herbicides to kill weed seedlings as they emerge in blueberry fields is September 1 to October 1 for winter weeds and February 15 to March 30 for summer weeds. Application of contact and systemic (translocated) postemergence herbicides may be required to control some difficult weed species.
Perennial weeds should be killed the summer before planting by cultivation and the use of a systemic herbicide, such as glyphosate. Weed control the first two years after planting is challenging and eliminating the perennial weeds before planting greatly reduces future weed problems.
An abundant source of irrigation water, free of sodium, low in calcium and with favorable levels of other minerals should be available onsite. Irrigation water can be obtained from wells or ponds with proper filtration. To learn more,read Soil Drainage and Irrigation for Blueberry Patches.
Kenneth Bailey, NCSU Cooperative Extension Service.