Plant Tissue Sampling

Fruit and Nut Crops

CropNumber of LeavesPlant Part (leaf)Time of Year
Apples50Mid shoot current growthMid-season
Apricots50Mid shoot of current growthMid-season
Avocado50Most recently fully expanded non-fruiting terminalsLeaves 5-7 months old
Cherry, sweet50Midshoot current growthJuly-August
Grapes, wine30-50Petioles opposite basal clusterFull bloom
Olive50Mature leaves from middle of non-bearing, current season shootLate June through early August
Peach25Leaves from midshoot current seasons growth flower clustersMid-summer
Pear50Leaves from midshoot current growthMid-summer
Raspberries50Most recently matured leavesFlower bud start
Strawberries25Leaves and petioles, most recently maturedAt flowering
Conifers252-3” terminal cuttingsSummer

Cut Flowers and Nursery Crops

CropNumber of LeavesPlant Part (leaf)Time of Year
Roses25-30Uppermost five-leaflet from a flowering shoot just showing color.None specified
Carnations30-505th and 6th pairs from non-flowering shoots.None specified
Chrysanthemums254th leaf from tipBud start to finish
Alstroemeria20First fully developedNone specified
Azaleas50Most recently maturedNone specified
Gypsophila50Most recently fully developedNone specified
Cyclamen15Top50 days after transplant
Gardenias25Most recently maturedNone specified
Geraniums15Most recently maturedNone specified
Gerbera15Most recently maturedNone specified
Hydrangeas15Most recently maturedNone specified
Kalanchoe154th leaf from tipNone specified
Lily, Easter15Most recently maturedNone specified
Poinsettias15Most recently maturedNone specified
Snapdragons25Most recently maturedNone specified