The right soil for blueberries
Recently, I've had several questions about growing blueberries from folks who have already bought blueberry bushes and planted them. Ooops! These bushes require careful planning.
Blueberry plants need special growing conditions. They require acidic, well-drained soil and full sun with a pH of 4-5. Amending the soil to that specificity is difficult, but possible. But first, take a soil sample and send to the University of Minnesota. Kits can be obtained from local county extension offices. The Beltrami County Extension office in the fairgrounds 4-H building. Call (218) 444-5722. One can get a soil bag, instructions and an address. And for $17, the Soil Lab will send you a report telling you what the pH is, the soil texture, and phosphorus potassium levels. Based on that, there will be recommendations on how much nitrogen and other soil amendments to add to soil.
One cannot dump a bunch of acid amendments all at once. It may take two to three years to prepare one's bed prior to planting, so a bed should be prepared instead of just each hole. Just living next to a pine tree is not the answer. Since blueberries can live 30 to 50 years, preparing soil adequately is a very wise investment. Most soils are typically at the acid end of the spectrum in this area of Minnesota instead of being toward base, but one can never be certain without a test.
If the pH of the soil is between 5.5 and 7.0, and the texture is sandy to sandy loam, the addition of acid peat is all that will be needed to prepare the soil. Mix 4 to 6 inches of acid peat into the top 6 to 8 inches of soil. In addition to acidifying the soil, the peat increases the soil organic matter content.
Sulfur compounds can be used to acidify the soil. Elemental sulfur takes at least one year to adjust the pH. This is why one needs to take a year or two to prepare the bed before starting blueberry plants. Aluminum sulfate is not recommended as it can be toxic to roots. Iron sulfate reacts much faster than elemental sulfur (less than one month). Cost is a factor here.
Most garden soil is not good blueberry soil, so modification of the soil is necessary. Soils with a pH greater than 7.0 will require higher rates of amendments and are not recommended for growing blueberries. Blueberry plants require a soil that is well-aerated and has a high water holding capacity in addition to being acidic. The recommended shrubbery varieties are "St Cloud" and "North Country" from the University of Minnesota Extension website.
So, good luck but just don't go buy several plants before testing your soil and planning the amendments well in advance of planting. There will be little blue rewards if one plans carefully. Or there is the Lake George Blueberry festival.
Refer to the revamped and updated University Of Minnesota Extension Service website
for more information on horticultural topics.
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