Plant analysis is an important second step to soil testing and most certainly should go hand in hand with it. A plant analysis will show what nutrients the plant is taking up throughout the entire rooting zone and whether the levels found are adequate, deficient or excessive. A soil test is limited to the depth of sampling, unlike a tissue analysis. Many people will look to a tissue analysis when trouble shooting by comparing a "good" with a "bad" area.
DEPARTMENT OF FOOD AND AGRICULTURE
Permit & Plant Health and Pest Prevention Instructions
Special Instructions for Regulated Plant Material Collected