|Last year I planted 2 blueberry bushes and a blueberry tree without testing the soil. Now that I tested the soil the pH is 6.4, how much sulfur do I add and do I mix it into the new compost I added this year?|
|Blueberries like a very acid soil - in the range of 4.0 to 5.5. You can change the pH of the soil with sulfur, but it takes a while for the sulfur to react. How much you apply really depends on a lot of things! Since you need to lower the pH quite a bit, enough powdered sulfur to make a difference in the soil will also kill off soil microorganisms that are vital to a blueberry plant's growth. It would almost be easier on your plants to dig them up, amend the soil with acidic organic matter and then replant. You'll need about a half bushel of amendments for each plant. Begin by spreading peat moss, compost or leaf mold over a 2'-3' circle of soil where the plant will be located. Mix with the native soil to a depth of about 8". The end result should be one-third native soil and 2/3 organic matter. Then plant and mulch around the plants with additional peat moss or leaf mold. Plan to add a 4"-5" thick layer of acidic mulch each year and feed with an acid based fertilizer to maintain the lower pH.
Hope your plants thrive!