Home gardeners can lower their soil pH by adding Canadian sphagnum peat to the soil. Sulfur can also be used to acidify the soil. Since sulfur reacts slowly with the soil, it should be applied and incorporated a year before planting. The following table lists the approximate amount of elemental sulfur required in pounds per 100 square feet to lower the soil pH to 4.5. 5.0 0.4 1.2 Aluminum sulfate should not be used to acidify the soil as large amounts of this compound can be toxic to blueberry plants.
Highbush blueberries are hardy in central and southern Iowa.
Plants develop into 6 to 8 foot shrubs. Half-high blueberries possess greater cold hardiness and are the best choice for gardeners in northern Iowa. Spring is the best time to plant blueberries. The roots of dormant, bare-root plants should be soaked in water for about an hour before planting. When using Canadian sphagnum peat to acidify the soil, dig a hole approximately 12 to 18 inches deep and 2 to 3 feet wide.