- - AGRICULTURE CORE CURRICULUM - -

(CLF6000) Advanced Core Cluster: ORNAMENTAL HORTICULTURE

 (CLF6500) Unit Title: SELECTION, PLANTING, AND CARE OF ORNAMENTAL PLANTS

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 (CLF6501) Topic: EVALUATION AND SELECTION       Time           Year(s) 
                    OF QUALITY PLANTS              2-3 hours       3 / 4 
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         Topic Objectives: Upon completion of this lesson, the student
                            will be able to:

         Learning Outcome #:

           (I-1) - List and discuss five factors to consider when
                     selecting quality shrubs and trees.
                     
           (I-2) - Evaluate in groups of four, trees, shrubs, flats, and 
                     potted plants (of a single variety in each set), judge
                     them in order of most desirable, and defend the 
                     reasoning behind the placement.

         Special Materials and Equipment: Different varieties of shrubs, 
                     trees, flats, and potted plants.

         References: Harris, R. W. (1983). ARBORICULTURE: CARE OF TREES,
                       SHRUBS, AND VINES IN THE LANDSCAPE. Englewood Cliffs,
                       NJ: Prentice-Hall.
                     Ingels, Jack E. (1985). ORNAMENTAL HORTICULTURE: 
                       PRINCIPLES AND PRACTICES. Albany, NY: Delmar
                       Publishers.

         Evaluation: Quiz, test, written paper, or instructor observation.

TOPIC PRESENTATION: EVALUATION AND SELECTION OF PLANTS

A. Evaluation and selection of quality plants is overlooked at times.

   1. Quality plants earn more money for the grower or retailer.

   2. Quality plants grow better for everyone from the grower to the 
       retail customer.

B. There are five factors to consider when selecting quality plants:

   1. Size

       a. Consider the overall size of the plant's shoot system in 
           relation to the root system. Is it too large or too small for 
           the container?

       b. The height of the tree or shrub

       c. On trees, the circumference of the trunk

       d. The spread of the tree or shrub

       e. The trunk taper

   2. Framework

       a. Branches are well-spaced and distributed.

       b. General shape is balanced.

       c. There are few or no broken branches.

   3. Pruning

       a. Pruning cuts should be properly made.
           (NOTE: Although it is still practiced, research shows that 
           properly timed and properly made pruning cuts do not need to be
           treated. Refer to CLF6550, Pruning & Training Ornamental Plants,
           for further details.)

       b. Interfering branches and dead wood should be removed.

       c. Trees should not be headed.

   4. Vigor

       a. Leaf color should be green or dark green (depending on species) 
           and large.

       b. There should be sufficient new shoot growth.

       c. The bark should be smooth and bright.

   5. Health

       a. The plant should be free of insects and/or diseases.

       b. Any damage by insects or disease should be minimal.

       c. Leaves should look healthy, i.e., they should be

           1) free of sunburn

           2) free of frost damage

           3) free of chlorosis

       d. Roots should be in good condition.

           1) They should not be growing out of the container.

           2) They should fill the container, but should not be circling or 
               kinked.

           3) There should be enough roots to hold the plant up.

           4) The roots should have a healthy color and consistency.

C. Factors to consider when buying plants.

   1. Some plants are sold seasonally.

   2. Some purchases are discounted.

   3. Know your grower or nursery and their rules, guarantees, cost for 
       special services, etc.

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         ACTIVITY: 
 
         1. Have students evaluate trees, shrubs, flats, or potted
             plants in groups of four. Then have them give oral 
             and/or written reasons for their choice.

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1/6/91 MT/clh

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