Landscape Plant Grades and Standards

Background:

The success of any landscape planting depends on many factors. Some of these factors highlight on the correct species selection. For example, if a landscape site is subject to ocean water spray, salty ground water, then if a species is planted that is not salt tolerant, it can be expected to not grow well. Other kinds of factors focus more directly on the particular individual plant selected after the correct species has been determined.

If a particular landscape plant is being considered for purchase by a landscaper, it is important for the landscaper to select the highest possible quality individual plant. If plants that have structural defects (such as, for example, girdled roots, codominant stems, acute angles of branch attachment, etc.) are chosen, they can fail in the landscape. Also, many municipalities require that newly installed landscapes pass inspection and landscape inspectors are required to ensure that the quality of the plant materials used in new landscape plantings meet minimum standards of quality.

In this exercise you will evaluate several nursery trees and shrubs using 2 different types of landscape grading procedures. The first procedure, published in the American Standard for Nursery Stock, is a nationally recognized procedure published by the American Nursery and Landscape Association. It is objective in nature, and it requires that the evaluator use easily measurable factors. The second procedure, the Florida Grades and Standards for Nursery Plants, requires the evaluator to make certain subjective determinations (value judgements), as well as objective measurements.

Procedure:

American Standard for Nursery Stock. Your instructor has procured several container grown trees. Work in groups (3-6 students per group is optimum) and each group will select at least 2 trees. Record your measurements and findings on separate sheets of paper that you will keep adjacent to this sheet in your laboratory notebook.

1. Each tree has a tag on which is printed a letter (in some cases, a letter and a number). Record the letter and proceed to the next step.
2. List the name of the tree and measure each tree’s caliper 6 inches above the soil level, branching height and overall height.
3. Although it is not required for grading, measure the caliper of each tree and record it for later use in calculating tree taper.

Florida Grades and Standards for Nursery Plants. Using the 2 trees selected for the exercise above, conduct the grading procedure and assign each tree as a Florida Fancy, Florida No. 1, Florida No. 2 or a Cull. Write a brief justification for your evaluation. Remember that factors such as root condition as well as branching structure and arrangement must be considered.