Friday quiz time!

Now I could have sworn I’d posted this puzzle before, but after searching through all the previous postings I can’t find it.  Here it is.

I planted this Cornus kousa in 1999 (removing the burlap, clay, etc. prior to installing).  We removed the turf (still attached to the $(%&$ plastic mesh) and planted the tree in the existing soil.  The first photo was taken in 2004, and the second was taken in 2007:


Here are some specifics about what was done to the landscape during this period: we replaced all the turf with wood chips and put in the fence as shown.  There was no impact on structural roots from either of these activities, and fine roots were affected minimally when we dug post holes for the fence.  The turf was simply allowed to die back in the summer (hot summers do that here in Seattle) and then topdressed with wood chips.  There were no chemicals applied, nor was there any soil disturbance.

It was about 2007 that we noticed the leaves were substantially smaller than previous years.  The leaves are sparse and small, but they don’t become chlorotic or necrotic during the summer, nor does any part of the tree suffer more than any other.  This phenomenon has continued until this year, when we finally dug it up and moved it elsewhere.

So here’s the question:  why did this tree start swirling down the mortality spiral?  As always, there may be many legitimate answers – but I’ll show you the actual reason on Monday!

Enjoy your weekend!

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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 a Professor in the Department of Horticulture, and holds two affiliate associate professor positions at University of Washington. 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 page - "The Garden Professors" Facebook group - Books:

9 thoughts on “Friday quiz time!”

  1. This one has me stumped. My thought was there looks to be more trees near the plant in the 2009 photo. Is it competition that is causing the problem?

  2. The tip that the leaves were large when you first planted the tree leads me to believe that it had probably been growing in a more shady environment. The leaf drop, smaller new leaves, and ultimate recovery seems to be adaptation to a more sunny sighting.

  3. My husband thinks something leeched out of the wood from the fence, slowly building up in the soil causing slow decline. I also wonder if fence installation caused soil compaction and suffocated the poor fella.

  4. I am going to guess overwatering. When the tree was originally planted you said there was lawn around it. It was probably on a sprinkler system. It was never adjusted to compensate for the missing turf. Then the fence was built, partially blocking the sprinkler from reaching its full distance. The fence blocks the water spray that would normally go out another 10-15′. This water then sits around tree causing it to be overwatered. When moved, the tree was no longer being overwatered and leafed out normally.

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