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Ornamental Horticulture Course Syllabus (HORT332)

Interior Plantscaping

Hort 332: Interior Plantscaping (3 credits) meets Tuesday and Thursday from 4:15 to 5:30 pm. The recommended preparation is an introductory biology or plant science course. This course covers the design, selection, installation, management, and maintenance of plantings within buildings as well as the effects of interior plants on people and the environment. Cooperative course taught by WSU, open to UI students (PLSC 332).


Use of the online Hort 332 portal in Angel is required. To use the Angel course space go to You will need your WSU network ID (NID) and password to login. All email communication for Hort 332 will also be via the Angel system, so you will need to know your WSU (not your personal) student email address.


Dr. Rita Hummel (Emeritus)
205A Kalkus Hall
WSU Puyallup Research and Extension Center

Instruction and Classroom Support Technician

Caroline Pearson-Mims
153 Johnson Hall
WSU Pullman

Required Text

  • Interior Plant Handbook by Rita L. Hummel

Recommended Text

  • Interior Plantscapes: Installation, Maintenance and Management (Third Edition) by George Manaker

Supplemental Texts/Media

  • Interior Landscaping by Tok Furuta
  • The Healthy Indoor Plant: A Guide to Successful Indoor Gardening by Charles C. Powell and Rosemary Rossetti
  • Tropical Foliage Plants by Lynn P. Griffith, Jr.

Hort 332 website

Course Topics

  • Introduction to interior plantscaping – the history, value, origins and future of interior plants; investigation of online and research information sources
  • Uses of plants in interiorscapes, LEED, design considerations, plant growth and plant growth control
  • Interior plant recognition, cultural requirements and uses – information on the individual plants used in commercial interiors will be integrated throughout all lectures
  • Plant-human relationships – physical, emotional and environmental justification for interior plantscaping; research overview of interior-plant effects on humans and the environment
  • Environmental factors limiting plant growth and maintenance indoors
    • light: intensity, duration, source, effects, modifications
    • temperature, humidity, air movement and quality
    • water: quality, quantity, methods of application, waterproofing
    • growing media and nutrients: salinity, selection
  • Plant problem diagnosis – recognition, prevention and control of common cultural, disease and insect problems on interior plants with emphasis on integrated pest management practices for interiorscapes
  • Planters – selection and maintenance considerations; living walls
  • Plant Acclimatization and Acceptance
  • Maintenance Practices and Schedules – equipment, plant pruning, grooming, girdling roots, potting, replacement, rotation, seasonal flowering plants, maintenance schedules
  • Installation and Maintenance Contracting – organization, image, client and industry interactions, specifications and cost estimates, contracts

Student Learning Outcomes

Upon successful completion of this course students will:

  • Recognize species and cultivars best adapted to commercial interiorscapes and determine their common names and scientific names.
  • Assess the impact of plants in the interiorscape on human quality of life.
  • Understand the environmental requirements of common interior plants.
  • Follow diagnostic protocol to evaluate biotic and abiotic problems of interior plants
  • Evaluate the existing indoor environmental conditions and modify conditions to enhance plant growth.
  • Find and interpret the usefulness of interior plantscaping resources including research articles and websites.
  • Investigate the effect of light intensity on interior plants through experimentation, collection and interpretation of data.
  • Select appropriate plant materials and accessories for use in interior landscaping.
  • Assess and plan appropriate interior plant installations.


  1. Observations of Interior Plant Use in American Life and Popular Media. Students will observe interior plant use in selected commercial interiorscapes and discuss the design intent; the same will be done for selected television shows and/or movies.
  2. Light Intensity and Plant Growth Class Research Project. Students will be given cuttings of Ledebouria socialis to root and grow at differing interior light intensities. Students will collect data on plant response to light intensity and report to the class. Data from all students will be combined for statistical analysis and each student will produce a report interpreting the results.
  3. Plant Assessment and Site Analysis Team Project. Student teams will select and analyze a commercial interior site giving consideration to plant selection and use, environmental parameters, plant health and maintenance requirements, and recommendations for improvement. Teams will present their projects to the class.
  4. Interior Plant Problem Diagnosis. Students will observe an interior plant with a biotic or abiotic problem and follow diagnostic strategy to systematically diagnose the problem.
  5. Journal Article Assignments. Students will read, analyze and interpret the significance of published scientific research.
  6. Design Project. (Optional, Extra Credit) After making arrangement with Dr. Hummel, students desiring extra credit will create a planting plan and plant list for a small-scale commercial interiorscape.


Grades will be based on three exams, plant identification quizzes, the assignments, projects and class participation.

Grading Scale

Grades will be assigned as follows:

93% or more
90% to 92.9%
87% to 89.9%
83% or 86.9%
80% to 82.9%
77% to 79.9%
73% to 76.9%
70% to 72.9%
67% to 69.9%
63% to 66.9%
0% to 62.9

Late/Make-Up Work

All projects are due on the date scheduled. Projects turned in late will be penalized at the rate of 10% of the possible points per day. There will be no make-up exams, quizzes or projects; if you miss one, you will receive a zero, unless there are extenuating circumstances and Dr. Hummel agrees to an alternative arrangement.

Reasonable Accommodation

Students with Disabilities: Reasonable accommodations are available for students with a documented disability. If you have a disability and need accommodations to fully participate in this class, please either visit or call the Access Center (Washington Building 217; 509-335-3417) to schedule an appointment with an Access Advisor. All accommodations MUST be approved through the Access Center. For more information contact a Disability Specialist on your home campus:

Academic Integrity

Academic integrity is the cornerstone of the university. Any student who attempts to gain an unfair advantage over other students by cheating, will fail the assignment and be reported to the Office Student Standards and Accountability. Cheating is defined in the Standards for Student Conduct WAC 504-26-010 (3). You can learn more about Academic Integrity on your campus at the Office of Student Standards and Accountability.

Safety and Emergency Notification

Pullman: Washington State University is committed to enhancing the safety of the students, faculty, staff, and visitors. It is highly recommended that you review the Campus Safety Plan ( and visit the Office of Emergency Management web site ( for a comprehensive listing of university policies, procedures, statistics, and information related to campus safety, emergency management, and the health and welfare of the campus community.

Tri-Cities: Students are encouraged to review the Tri-Cities Campus Safety Plan, which contains a listing of emergency contacts, and university policies, procedures, statistics, and information relating to campus safety and the health and welfare of the campus community. The Campus Safety Plan can be found at