Sustainable Horticulture


September 1 – December 8, 2021

To Enroll – Start Here

Linda Chalker-Scott, PhD, Horticulture      Email:

  • Extension Urban Horticulturist, Puyallup Research and Extension Center, Washington State University
  • Associate Professor, Horticulture and Landscape Architecture, Washington State University

LCS head shot

Course description

This is a one-semester introduction to the applied plant and soil sciences necessary to managing gardens and landscapes sustainably. Students will learn how to assess the site and soil conditions necessary for proper plant selection. Next, they will discover the proper way to prepare both plants and soil for installation designed to maximize root establishment. Finally, students will develop the ability to diagnosis signs of biotic and abiotic stress in landscapes and determine the best treatment. Throughout the course students will be exposed to the numerous myths and misperceptions prevalent in the fields of landscape horticulture and arboriculture.

Resources from the instructor:

Weekly Content

Week 1 – Introduction and basics

  • Scope of course – landscapes vs. production agriculture
  • Fact or fiction?
  • Assessing information
  • Practical plant and soil sciences

Week 2 – Site analysis

  • Environmental variable
  • Urban soils
  • Soil testing

Week 3 – Plant selection

  • Landscape functions
  • Choosing quality nursery plants
  • Native vs. nonnative plants

Week 4 – Project #1: Plant quality assessment. Due 1 week after assignment

Week 5 – Sustainable soil management

  • Soil preparation and protection
  • Amendments vs. mulches

Week 6 – Landscape plant installation

  • Root preparation
  • Planting
  • Aftercare

Week 7 – Project #2: Installation assessment. Due 1 week after assignment

Week 8 – Water management

  • Water sources
  • Water mobility in landscape
  • Climate change

Week 9 – Nutrient management

  • Plant nutrients
  • Fertilizers – commercial vs. homemade
  • Dealing with nutrient deficiencies and toxicities

Week 10 – Plant health management

  • Pruning
  • IPM for landscape horticulture
  • Diagnosing abiotic and biotic problems

Week 11 – Myth busting – focus on products

Week 12 – Myth busting – focus on practices

Week 13 – Project #3: Scientific literacy: analyzing information. Due 1 week after assignment

Week 14 – Special situations

  • Home vegetable gardens
  • Ecological restoration


Your grade is based on 1000 points, 600 from three one-week-long individual projects,300 from your participation in the weekly discussion forums, and 100 for a critical analysis of a university extension educational resource.

Projects (3 @ 200 points each = 600 points)

Discussion forum (15 weeks @ 20 points each = 300 points)

Extension information analysis (100 points)

Prerequisites and Textbooks

There are no prerequisites, although it will help your success to have an introductory understanding of botany and soils. Lack of this background may require you to do outside reading.

There is no required textbook, though there are several optional books by the instructor and others that may be useful to you in this course:

Chalker-Scott, L. 2015. How Plants Work: The Science Behind the Amazing Things Plants Do. Timber Press, Portland, OR. (An accessible introduction to plant physiology that explains the science behind what plants do every day.)

Chalker-Scott, L. 2010. The Informed Gardener Blooms Again. University of Washington Press, Seattle, WA.(The second of two volumes of common horticultural myths, described and debunked.)

Chalker-Scott, L. (ed.) 2009.Sustainable Landscapes and Gardens: good science – practical application. GFG Publishing, Yakima, WA.(Written for gardeners, this multi-authored book contains the most current and relevant science for choosing, planting, and caring trees and shrubs.)

Chalker-Scott, L. 2008. The Informed Gardener. University of Washington Press, Seattle, WA. (The first of two volumes of common horticultural myths, described and debunked.)

Dirr, M. A. 2009. Dirr’s Hardy Trees and Shrubs, 6th edition. Timber Press, Portland, Ore. (A long-lived publication on selecting trees and shrubs for your home gardens and landscapes.)

Gillman, J. 2008. The Truth About Garden Remedies: What Works, What Doesn’t, and Why. Timber Press, Portland, OR. (This book assesses new and historic advice and reveals the how and why‚ and sometimes the why not‚ for more than 100 common and uncommon gardening practices.)

Gillman, J. 2008. The Truth About Organic Gardening: Benefits, Drawbacks, and the Bottom Line. Timber Press, Portland, OR. (This book introduces over 100 gardening products and practices—organic and synthetic—and examines each to determine whether it is safe and whether it accomplishes the task for which it is intended.)

Harris, R. W., J. R. Clark, and N. P. Matheny. 2003. Arboriculture: Integrated Management of Landscape Trees, Shrubs and Vines. 4th edition. Prentice Hall, Upper Saddle River, N.J. (A research-based textbook with practical information on caring for landscape trees. A bit dated on some topics.)

Reich, L. 2010. The Pruning Book, 2nd edition. The Tauton Press, Newtown, CT. (Clear and accurate explanations of proper pruning techniques.)

There are also some webpages and online blogs that are helpful:

The Garden Professors blog

The Informed Gardener webpage (LCS university page)

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