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

When criticism becomes libelous

Dr. Cregg is on vacation for a few weeks so I thought I’d post something today by trolling the web for discussion of my horticultural myth columns.  And when you go fishing, you know you might catch something you didn’t really want.  In this case, personal and professional attacks.

Like the rest of the GPs, I relish vigorous debates on different horticultural practices and products.  Ideally, these debates are based on science, so that we’re all friends afterwards and could go out for beer if we all lived in the same community. … Continue reading this article “When criticism becomes libelous”

Five little lavenders – an update

Long-time readers of our blog might remember my August 12 column (linked here for your convenience).  You saw my giant lavender plant devolve into 5 small plants with tiny spiraled root systems that put Marge Simpson’s beehive to shame.  In any case, I promised to keep you up-to-date with their progress.

Transplanting in August is a risky proposition, especially when you prune out root defects.  Nevertheless, all but one of the five survived the summer and here they are earlier this spring:

The one that didn’t make it was in the upper left corner of this south-facing landscape, where there is a lot of reflected heat from the nearby bricks and concrete. … Continue reading this article “Five little lavenders – an update”

Clematis mystery solved

Friday’s quiz was a tough one. Bernadette and Lisa B. gave it a good shot, guessing that this might be a phosphorus deficiency. While they’re on the right track (it is a nutritional disorder), the mineral of interest is iron, and it’s a toxicity problem, not a deficiency.

Under wet conditions (the affected Clematis is in the part of our landscape with a perched water table – see the March 15 posting), iron is predominantly in the Fe+2 form (ferrous) rather than the Fe+3 form (ferric).… Continue reading this article “Clematis mystery solved”

Friday quiz – a tale of two clematis

These two Clematis are the same cultivar growing in my landscape about 15 feet apart. Both are growing on a fence facing north. Compare the leaves of the two:


Normal, happy Clematis


Not-so-happy or -normal Clematis

What do you think is causing the leaf discoloration? Very large hint: this is not a biotic stressor. Another hint: you’ve seen this part of our landscape before…back in March. For full credit, identify both direct and indirect environmental stress (in other words, [1] what is directly causing the discoloration in the leaves, and what is allowing [1] to occur, thereby causing stress indirectly)?… Continue reading this article “Friday quiz – a tale of two clematis”

An interesting blog for science-loving oenophiles

There’s a new blog already generating a lot of discussion among wine aficionados.  The not-so-subtly named “Biodynamics is a hoax” discusses all things related to Rudolph Steiner and his philosophies, including the pseudoscience of biodynamics.

Organic farming study at – gasp! – a research university

There is a common misperception among some that university researchers are in the pocket of Big Ag (see June 11 and 13 posts). So here’s a link to an article in today’s Seattle Times about the benefits of organic farming from a study at Washington State University.  The research was published in Nature (one of the most revered of the scientific journals).

Cornmeal myth busted

As my colleague Fred Hoffman says, the horticultural silly season is upon us. This week I heard from one of our European readers, questioning the use of cornmeal as a fungicide. He referenced an online article entitled “Cornmeal has powerful fungicidal properties in the garden.” He hadn’t been able to find any reliable information and thought it might make a good topic for our blog. So Johannes, this rant’s for you!

If you’ve followed the link to column in question, you’ll see that the original “research” is attributed to one of Texas A&M’s research stations in Stephenville, TX.… Continue reading this article “Cornmeal myth busted”

Garden seminar coming to a place near you?

I just got back from British Columbia where I spoke to 2 garden club/Master Gardener groups.  It’s always easy for me to do seminars in BC or along the west coast, but I rarely get a chance to go elsewhere.  Many times it’s the expense that keeps groups, especially garden clubs and nonprofits, from bringing in speakers.

So here’s my idea:  I keep a gift account budget here at WSU with the donations people make towards my educational program. … Continue reading this article “Garden seminar coming to a place near you?”

Mystery berry revealed

You guys are just too smart – I was hoping to trap someone into guessing a Vaccinium species. But no, you all knew this was a Taxus spp. (yew):

Because Taxus is a gymnosperm, this reproductive structure is actually a cone.  It’s botanically incorrect to call it a fruit of any sort, as the term "fruit" refers specifically to angiosperms. Taxus cones are modified for seed dispersal to include an edible, fleshy aril (very good, @GardenHoe!),… Continue reading this article “Mystery berry revealed”

Friday mystery

I just got back from Nanaimo BC, where I had gooseberries with my afternoon tea.  Below is another "berry" found on a commonly used ornamental.  (I use the term berry loosely – as you may know, the botanical definintion for berry excludes fruits like strawberry and raspberry, which are aggregate fruits.)

I’ve photoshopped this so that only the two "berries" are visible. On Monday I’ll post the entire photo, along with some botanical fun facts! See if you can guess what this is before then.