How can I fertilize so plants are best able to tolerate winter cold?
This question has not been well-researched in blueberries, although there are numerous opinions and some related information in other crops. Hardiness is optimized by maintaining nutrient levels in the sufficient ranges, and by minimizing overall plant stress (drought, over-cropping, diseases, foliar pest feeding). The nutrient most often associated with cold hardiness is nitrogen. Excessive N use has been shown to reduce the hardiness of some fruit trees, and anecdotal observations suggest this is also true of blueberries. The key is to apply recommended rates at the right time. Nitrogen applications after June should be avoided because this may encourage additional flushes of shoot growth late in the season, which may not harden off in time for winter. The bottom line is that following good cultural practices including fertilization recommendations optimizes hardiness. Use periodic leaf analyses and soil tests to monitor plant nutrition and make sure your fertility program is best fo
