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

A salt bath for your tomatoes?

This morning I got an email from one of my gardening colleagues, wondering about the wisdom of watering tomato plants with salt water.  He had a link to a UC Davis website which tacitly endorses spraying tomato plants with 10% salt water “to increase their nutritional value and taste.” Unreferenced “worldwide studies” are mentioned, along with the “major potential benefit of providing irrigation for crops in areas with freshwater restrictions.”

Before we deal with the impracticalities and out-and-out harm of using salt water for irrigation, let’s look at why this practice would work on tomatoes. … Continue reading this article “A salt bath for your tomatoes?”

Wet trunk – the whole story

We had a flurry of discussion on this over the weekend. The diversity of possible answers shows you how difficult it is to do diagnosis with only some of the information available. That being said, several of you (Gail, Tom, Dave and Jimbo) all had portions of the problem identified. Here’s the whole picture:

As both trunks of this double-leadered tree have continued to expand in girth, they’ve created the perfect conditions for disease to occur in the narrow constriction between the trunks.… Continue reading this article “Wet trunk – the whole story”

Friday puzzle: wet trunk

Another diagnostic question today.  Below you can see the lower portion of a tree trunk whose left half is obviously wet:

What is directly causing the wetness (in other words, what environmental factor), and can you guess what led to this problem indirectly?

I’ll eliminate some of the obvious possibilities:  it’s not from dog pee, nor is it from a directional sprinkler.  And the answer to the second question is not in this close up photo, but will be revealed on Monday.… Continue reading this article “Friday puzzle: wet trunk”

Parking tickets, compost tea, and pseudoscience in the Ivory Tower

Back in November 2009, Jeff posted an educational and amusing commentary about Harvard’s use of compost tea. Much vigorous discussion followed, and we’ll return to that topic in a moment. But first, I’d like to tell you about my morning yesterday.

In September of 2010, I received a ticket for parking longer than 2 hours in a restricted zone. Now, there was no way I committed this infraction; I had hard core proof that could not be rationally challenged.… Continue reading this article “Parking tickets, compost tea, and pseudoscience in the Ivory Tower”

The roots of the rhody problem

There were several good shots at analyzing Friday’s unhappy rhododendron.  Mature leaf size can be determined by light levels, as both Lisa B and Tom &  Paul suggested.  Moving a plant from a low to high light environment could cause this change in leaf size.  This rhododendron hasn’t been recently transplanted, however, so we can eliminate light levels as a cause.  (And there was no other impediment to light, such as the presence of shading plants.)… Continue reading this article “The roots of the rhody problem”

Friday puzzle: unhappy rhododendron

Today we have a diagnosis question. Consider this unhappy rhododendron:

While there is more than one problem with this poor thing, the one I’d like you to think about is why the newer leaves are smaller than the old leaves. (They are fully mature.) There are two parts to this question:

1) What is the physiological reason that the leaves are smaller? (In other words, what is directly causing this difference?)
2) Knowing this, what does this tell you about the underlying problem?… Continue reading this article “Friday puzzle: unhappy rhododendron”

Random thoughts from the NW Flower and Garden Show

Last week was Seattle’s NW Flower and Garden Show. This multi-day extravaganza features display gardens, educational seminars, and many opportunities to spend $$$. I had a little free time one day and shot some pictures, which I present here along with my commentary:

The Good

The “perfect” lawn is no longer just a monoculture of grass.  At least two of the display gardens had flowers scattered for a designer version of ecoturf:

And a very cool repurposing of old heating vent covers as part of a patchwork of groundcovers:

The Questionable

A gorgeous Japanese maple (Acer palmatum), “born” in 1893:

I’m sorry.… Continue reading this article “Random thoughts from the NW Flower and Garden Show”

Mystery teeth revealed

Friday’s puzzle was tough!  Several of you were on the right track – this is a carnivorous plant. Right away Deb suggested a pitcher plant (then got sidetracked with chestnuts), but Derek was spot on with his guess of the “spiky bits” on a Nepenthes pitcher:

What the function of these spiky wings are is not clear to me; I did a little checking in the literature but failed to find anything convincing.  It does seem to suggest a close relationship with fly traps. … Continue reading this article “Mystery teeth revealed”

Friday mystery teeth

I’ve spent most of this afternoon at the NW Flower and Garden Show.  During my visit, I snapped a photo of this toothy plant part:

So the questions for today are….

What is this plant part?
What plant did it come from?
(And if you know its scientific name, that actually answers both questions at once.)

My husband is convinced this is too small a part of the plant for anyone to figure out the answesr. … Continue reading this article “Friday mystery teeth”

Tree terrors continue

You might remember back in October 2009 I gave one of the first Friday quizzes.  The featured tree had epicormic shoots, and Monday’s answer revealed the neglected wire staking that was slowly girdling the main trunk.  (Be sure you click on those links to see what the tree looked liked in 2009.)

I thought you might be interested to see what this tree looks like now:

A picture is worth a thousand words….many of those unprintable.… Continue reading this article “Tree terrors continue”