For tree fruit and blueberries collect 100 leaves from the middle of this years growth. Collect these leaves from as many different plants as possible within the sample area. Wash the leaves by swirling them in soapy water then rinse and blot dry. Place the dry leaves in a paper bag and let them dry at room temperature. Samples can be submitted to any MSUE county office.
Grapes are a little different.
In grapes, we usually wait until the beginning of veraison, in early to mid August when the berries change color. The tissue sampled is the petiole or leaf stem and not the entire leaf. The sample is taken from the most recently matured leave on the shoot. It is not necessary to wash grape petiole samples. These bulletins have color pictures of nutrient deficiencies and discuss the signs of healthy and deficient nutrition in fruit plantings and should be in every fruit grower's library.