Do not use fertilizer the year you set out the plants because the roots are easily damaged at this time. When plants flower during the spring of the second year after transplanting, apply 4 ounces of ammonium sulfate or 2 ounces of urea to each plant. Sprinkle the fertilizer in a ring around the bush, but don't work it into the soil because it might damage the shallow roots. Never fertilize after flowering as it may make the plants more prone to winter injury.

Increase the amount of ammonium sulfate you apply to each plant by 1 ounce each year (1/2 ounce for urea) until the sixth year. After that time, use 8 ounces of ammonium sulphate (4 ounces of urea) per application. Fertilizers containing chlorides or nitrates are not recommended because they can harm blueberry roots.

Sometimes plants need supplemental fertilization with magnesium sulfate and a balanced fertilizer. To find out, you can test the soil. (Contact your county's Cornell Cooperative Extension office for soil testing information; see www.cce.cornell.edu/local_offices.cfm.) For a more precise assessment, you have a leaf analysis done (cost: about $30; for more information, contact the Cornell Nutrient and Elemental Analysis Laboratory; phone 607-2551785, on the web at www.hort.cornell.edu/department/facilities/icp).

0 0

Post a comment