Author: Linda Chalker-Scott

Dr. Linda Chalker-Scott has a Ph.D. in Horticulture from Oregon State University and is an ISA certified arborist and an ASCA consulting arborist. She is WSU’s Extension Urban Horticulturist and an Emerita Professor in the Department of Horticulture. She conducts research in applied plant and soil sciences, publishing the results in scientific articles and university Extension fact sheets. Linda also is the award-winning author of five books: the horticultural myth-busting The Informed Gardener (2008) and The Informed Gardener Blooms Again (2010) from the University of Washington Press and Sustainable Landscapes and Gardens: Good Science – Practical Application (2009) from GFG Publishing, Inc., and How Plants Work: The Science Behind the Amazing Things Plants Do from Timber Press (2015). Her latest effort is an update of Art Kruckeberg’s Gardening with Native Plants of the Pacific Northwest from UW Press (2019). In 2018 Linda was featured in a video series – The Science of Gardening – produced by The Great Courses. She also is one of the Garden Professors – a group of academic colleagues who educate and entertain through their blog and Facebook pages. Linda’s contribution to gardeners was recognized in 2017 by the Association for Garden Communicators as the first recipient of their Cynthia Westcott Scientific Writing Award. "The Garden Professors" Facebook group - www.facebook.com/groups/GardenProfessors Books: http://www.sustainablelandscapesandgardens.com

Planting with a “flare”

Anyone who plants or cares for woody plants eventually hears the term “root flare” (or root crown). It’s easy to describe a root flare (it’s the region where stem or trunk morphs into roots). What’s sometimes difficult or even impossible is finding it in improperly planted trees and shrubs.

 

 

 

 

One of the primary causes of tree and shrub failure is improper planting depth. This is not a problem with bare-root plants, as you can easily see the region of transition.… Continue reading this article “Planting with a “flare””

Keep the fabrics in your closet and off of your soil

One of the “advantages” of being in the same office suite as me is hearing (a) that arborist wood chips are about as close to a miracle product as you can get and (b) that landscape fabric is hell on (the) earth. So my office mate Liz, either because she was convinced of the above or just wanted to shut me up, decided to rip out the landscape fabric in her ornamental bed and replace it with wood chips.… Continue reading this article “Keep the fabrics in your closet and off of your soil”

Rethinking the monocultural lawn (again)

Over the last couple of weeks I’ve been in London having some unforgettable garden experiences. Thanks to the generosity of my UK colleagues Glynn Percival and Jon Banks I was treated to Kew Gardens, RHS Wisley Gardens, and Windsor Castle. I hope to construct several blog posts from these visits, but today’s post is an homage to the English garden meadow. Instead of monocultural turf lawns, mowed and sprayed into submission, why not consider a more biodiverse and visually pleasing approach to groundcover?… Continue reading this article “Rethinking the monocultural lawn (again)”

Is it good advice? Or is it CRAP?

In my educational seminars I’ve long shared a version of the CRAAP test (currency, relevance, authority, accuracy, and purpose) for analyzing information related to gardens and landscapes. My version is CRAP (credibility, relevance, accuracy, purpose), and we’ve published an Extension Manual that explains in detail how to apply it. This past week I was at the Philadelphia Flower Show participating in Bartlett’s Tree Care Update panel. Given that the theme of the show was “Flower Power,” I figured that a talk on Magical Mystery Cures was in order.… Continue reading this article “Is it good advice? Or is it CRAP?”

A Gardener’s Primer to Cold Hardiness, Part 2

Last week I discussed the mechanics of how cold hardy plants can survive temperatures far below freezing. Today we’ll consider the practical implications of this phenomenon and what, if anything, you can do to help your plants through cold snaps.

What happens when temperatures change at unusually high rates?

Remember, supercooling occurs when temperatures drop slowly, allowing water to leave living cells and freeze in the dead spaces between cells. When rates drop quickly, which can happen on sunny winter days once the sun goes down, water can freeze inside the cells before it has time to migrate into the extracellular space.… Continue reading this article “A Gardener’s Primer to Cold Hardiness, Part 2”

A Gardener’s Primer to Cold Hardiness, Part 1

With record low temperatures in some parts of the country, gardeners are understandably worried about the ability of their perennial and woody plants to survive the cold. What today’s post will do is give you some context for understanding how plants can survive temperatures far below freezing.

Why ice floats and how this damages cells

Everyone knows that ice floats, whether it’s an iceberg in the ocean or cubes in your favorite chilled beverage. Ice is lighter than water because its molecular structure is different: there is more space between water molecules in ice.… Continue reading this article “A Gardener’s Primer to Cold Hardiness, Part 1”

Your New Year’s resolution : No “alternative facts” or “fake news” in 2019!

Welcome to 2019! In keeping with the tradition of a new year, I’m hoping you will join me in resolving to promote good gardening science among your friends, relatives, colleagues, and customers. One of the most important tools you’ll need is a collection of resources that are not only science-based, but are relevant to gardens and landscapes (not agricultural production). With that in mind, here’s my list of authors and institutions who are credible resources.

First off, of course, I’ll have to start with the Garden Professor faculty.… Continue reading this article “Your New Year’s resolution : No “alternative facts” or “fake news” in 2019!”

What’s wrong with my plant? You’re not going to find pat answers.

As many of you know, the Garden Professors host a Facebook group dedicated to the discussion of science-based practices for gardens and landscapes. (Side note – if you haven’t joined us please do!) Recently we’ve had a spate of “what’s wrong with my plant” posts, usually focusing on some leaf issue and little other information. And far too often an eager group member will jump in with a fertilizer recommendation.  So today’s blog post has two objectives: explaining why you can’t reliably diagnose problems from a picture of suffering leaves and why blanket fertilizer recommendations should be avoided.… Continue reading this article “What’s wrong with my plant? You’re not going to find pat answers.”

“Fun-guy” in your Mulch

By Jim Downer

As many avid GP readers are aware, mulches are a common horticultural tool that help gardeners maintain soil moisture, nutrient content, weed suppression and assist in disease prevention.  The best mulch is made from chipped tree trimmings wastes and has a large wood content.  Coarse “arborist chips” mulch is fast becoming one of the most frequently sought after mulches for residential landscapes.  It is very effective and contributes to significant soil improvements over time. … Continue reading this article ““Fun-guy” in your Mulch”

Native vs. nonnative – can’t we all just get along?

Probably the most contentious gardening topic I deal with online is the native vs. nonnative plant debate. This, unfortunately, is a debate that is more based in emotion than science, and I don’t intend to stir that pot again. We’ve discussed it on this blog before (you can find a list of them here), and I’ve published both a literature review and a fact sheet on the science relevant to tree and shrub selection. What I want to do in this post is compare two research papers, both in peer-reviewed journals, that come up with dramatically different conclusions.… Continue reading this article “Native vs. nonnative – can’t we all just get along?”