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  • Lesson B1-5:

    Growing Potted Chrysanthemums

    Unit B. Floriculture

    Problem Area 1. Greenhouse Crop Production

    Lesson 5. Growing Potted Chrysanthemums

    Learning Goal: Understand the fundamental concepts, principles and interconnections ofthe life, physical and earth/space sciences.

    Learning Standard: Know and apply concepts that explain how living things function,adapt and change.

    Learning Benchmark: Explain changes within cells and organisms in response to stim-uli and changing environmental conditions (e.g., homeostasis, dormancy).

    Skill Standard: Plant and care for potted plants in the greenhouse and nursery.

    Student Learning Objectives. Instruction in this lesson should result in studentsachieving the following objectives:

    1. Discuss the history and importance of the chrysanthemum.

    2. Explain the classifications of chrysanthemums.

    3. Describe how chrysanthemums are propagated.

    4. Schedule a potted chrysanthemum crop.

    5. Identify major chrysanthemum pests and disorders, as well as controls.

    Horticulture Lesson Plan Library

    Unit B. Problem Area 1. Lesson 5. Page 1.

  • List of Resources. The following resources may be useful in teaching this lesson:

    Recommended Resources. One of the following resources should be selected to accompany the


    Biondo, Ronald J. and Dianne A. Noland. Floriculture: From Greenhouse Production

    to Floral Design. Danville, IL: Interstate Publishers, Inc., 2000. (Textbook,

    Chapter 8)

    Other Resources. The following resources will be useful to students and teachers:

    Boodley, James W. The Commercial Greenhouse. Albany, NY: Delmar Publishers,

    1998. (Textbook, Chapter 21)

    Ball, Vic, Editor. The Ball Red Book. Batavia, IL: Ball Publishing, 1998. (Reference


    Schroeder, Charles B., et al. Introduction to Horticulture. Danville IL: Interstate

    Publishers, Inc., 2000. (Textbook, Chapter 11)

    McMahon, Robert W. An Introduction to Greenhouse Production. Columbus, OH:

    Ohio Agricultural Education Curriculum Materials Service, The Ohio State

    University, (Textbook, Chapter 11)

    List of Equipment, Tools, Supplies and Facilities

    Writing surface

    Overhead projector

    Transparencies from attached masters

    Copies of student lab sheets


    LCD projector

    Industry catalogs

    Terms. The following terms are presented in this lesson (shown in bold italics):

    Center bud removal



    Grading cuttings

    Hard pinch

    Response group

    Roll out pinch

    Soft pinch

    Horticulture Lesson Plan Library

    Unit B. Problem Area 1. Lesson 5. Page 2.

  • Interest Approach. Use an interest approach that will prepare the students for the les-son. Teachers often develop approaches for their unique class and student situations. A possible

    approach is included here.

    Set several types (different sizes, flower types, and flower colors) of potted chrysanthemums on the front

    desk or table at the head of the classroom before the students enter. As students enter class they will be cu-

    rious as to why the plants are there. They may find them attractive and ask what they are. Avoid answer-

    ing their questions to create more mystery. When class begins, ask the class a series of questions including

    what the plants have in common, how they are different, and whether they are the same. From there,

    move into the lesson.

    Summary of Content and Teaching Strategies

    Objective 1: Discuss the history and importance of the chrysanthemum.

    Anticipated Problem: What is the history and importance of the chrysanthemum?

    I. Chrysanthemums, commonly referred to as mums, have their origin in China, Japan and Eu-


    A. Up until the 1940s, chrysanthemums were grown in the United States primarily as gar-

    den plants. Since then, they have been grown widely as cut flowers and potted flowering

    plants. Chrysanthemums rank second to poinsettias in terms of the number of pots sold

    in the United States.

    B. Chrysanthemums are photoperiodic and thermoperiodic.

    Begin the lesson on chrysanthemums by focusing on the history and importance of the plant. Have the stu-

    dents read the appropriate sections in Chapter 8 of Floriculture: From Greenhouse Production to Floral

    Design and seek additional information through the Internet. Lead a class discussion on the history of

    chrysanthemum, during which students should be required to take notes. Use questioning to determine the

    level of student understanding of the topic.

    Objective 2: Explain the classifications of chrysanthemums.

    Anticipated Problem: What are the classifications of chrysanthemums?

    II. Chrysanthemums are classified based on their response group, plant height, and flower


    A. Response group refers to the number of weeks it takes for the chrysanthemum to flower

    from the time they begin receiving short day treatments.

    1. Response groups range from 6 weeks to 15 weeks.

    2. Most potted chrysanthemums fall into the 9-week or 10-week response groups.

    B. Chrysanthemum varieties are classified as being short, medium or tall.

    Horticulture Lesson Plan Library

    Unit B. Problem Area 1. Lesson 5. Page 3.

  • 1. Short varieties grow less than 15 in height.

    2. Medium varieties grow around 15 in height.

    3. Tall varieties grow more that 15 in height.

    C. Chrysanthemums are grouped in one of nine major flower forms including standard,

    spray, button, spoon, decorative, daisy, spider, pompon, and anemone.

    Acquire industry catalogs (they need not be of the current year) for use by the students to help them un-

    derstand how chrysanthemum cultivars are classified. Show the students how the catalogs are organized.

    Assign portions of Chapter 8 of Floriculture: From Greenhouse Production to Floral Design that address

    the classification of chrysanthemums. Purchase samples of the major floral forms from a wholesale florist

    for the students to identify. Use transparency master TM: B1-5A, Chrysanthemum Flower Forms to il-

    lustrate the different chrysanthemum flowers.

    Objective 3: Describe how chrysanthemums are propagated.

    Anticipated Problem: How are chrysanthemums propagated?

    III. Chrysanthemums are propagated asexually by stem cuttings.

    A. A few major companies produce 95% of the cuttings used in commercial production.

    Those companies provide rooted or non-rooted cuttings free of viral disease.

    B. Steps to propagating chrysanthemums are as follows:

    1. Take cuttings 2 to 3 inches in length with three leaves.

    2. Treat the cutting with a medium-strength rooting hormone.

    3. Stick the cuttings and place under an intermittent mist system.

    4. Maintain bottom heat between 70 and 75 degrees F.

    5. Light the cuttings to maintain vegetative growth.

    6. Fast rooting cuttings form roots in about 18 days.

    Assign the section regarding chrysanthemum propagation in Chapter 8 of Floriculture: From Greenhouse

    Production to Floral Design as a reading activity for homework or during supervised study. After the stu-

    dents have completed the reading assignment, discuss the way chrysanthemums are propagated. Obtain

    rooted or non-rooted cuttings for the students to pot and grow.

    Objective 4: Schedule a potted chrysanthemum crop.

    Anticipated Problem: What is a growing schedule for a potted chrysanthemum crop?

    IV. In preparing a production schedule, first determine the sale date. Then count back the num-

    ber of weeks the plant requires short day treatment and another 2 weeks for vegetative

    growth. After potting, a potted chrysanthemum schedule can be divided into the following


    A. The quality of the crop often hinges on the care taken at planting time.

    Horticulture Lesson Plan Library

    Unit B. Problem Area 1. Lesson 5. Page 4.

  • 1. Grade cuttings or sort them according to the number of roots, the diameter of the

    stem, and the length of the stem before potting. This ensures uniform growth in each


    2. Use a growing medium with a pH between 6.0 and 6.5.

    3. Plant cuttings shallow and angle them outwards over the lip of the pot at about 45


    B. The most important stage of growth is the vegetative stage. Strong roots and

    reserves of sugars must be established.

    1. Fertilize at a rate of 250-350 parts per million nitrogen at the first watering.

    2. Drop the rate to 200-300 parts per million nitrogen and potassium with following


    3. Provide 65 to 70 degree F night temperatures and 75 to 80 degree day temperatures.

    4. Maintain vegetative growth by interrupting the darkness by lighting between 10:00

    p.m. and 2:00 a.m.

    5. Grow the plants until the roots appear at the bottom of the pots, then pinch to pro-

    duce a well-branched plant with many flowers.

    a. Use a roll out pinch or the removal of just the tip of the stem in winter.

    b. Use a soft pinch or the removal of to inch of the stem and leaving five to six


    c. Use a hard pinch to remove all but three or four leaves in the summer.

    d. Flower bud initiation is accomplished by turning off the lights to provide a short

    day treatment. Covering the crop with black cloth might be necessary to simulate

    short day conditions.

    e. Lower temperatures to 62 to 65 degree F at night.

    f. Reduce fertilizer rates to 200-250 parts per million nitrogen and potassium.

    C. The flower bud development stage focu