Author: Linda Chalker-Scott

Okay, I’m biased:  I’m a whole plant physiologist, meaning that I like to study entire plants in their environment, not just their cells or DNA in a lab.  I got hooked on plants as an undergraduate in marine biology when I took plant physiology for “fun” (translated: I couldn’t find another biology elective to fill the time slot).  Discovering why vines curl around fenceposts (thigmotropism) or how plants sense gravity (statoliths) or why bilaterally symmetrical flowers evolved (to accomodate pollinators) was fascinating, and I finally succumbed to the green side when I entered my PhD program.

The book I used as a student was Salisbury & Ross’s Plant Physiology.  There were other texts out there, but this was my bible and I used newer editions when I began to teach Plant Physiology.  Recently (as some of you know) I’ve begun to write a garden book on how plants work.  Plant physiology, of course, is the underlying science, and I needed a new text for fact checking.

Salisbury and Ross, sadly, has not been updated since 1991, so I went with Taiz and Zeiger (which has also been around a long time).  It was a shock for me to discover that plant physiology has somehow morphed into plant molecular biology.  The books is full of gene acronyms and regulatory pathways…but very little of what fascinated me as a student.

Science has been on the reductionist pathway for a long time, and there’s no denying that understanding how genes are regulated is important.  But except for the fields of human and veterinary medicine, we’re losing our understanding of how organisms work.  Faculty experts who specialized in studying algae or mosses or grasses or trees for the sole purpose of increasing our understanding of these species have been replaced with those whose research programs can generate big dollars for cash-strapped universities.  The void left by academia’s abandonment of practical plant science is quickly filled with pseudoscience and mysticism, particularly in alternative agriculture.

All I can say is that if I had been confronted with the 2010 Taiz and Zeiger text as an undergraduate I would have a PhD in marine biology instead.

I just can’t resist telling our Christmas tree hunting tradition.

On the Friday after Thanksgiving, we drive out to Monroe (about 45 minutes north of Seattle) to our favorite tree farm, where we look for the perfect noble fir.  Here, Jim demonstrates his dubious taste in trees:

This year, Charlotte brought a tennis buddy home from college. Nasko lives in Bulgaria and wasn’t traveling home for a holiday they don’t celebrate.  So he got to experience the Great Scott Tree hunt for himself:

My son Jack (on the left) complained that he NEVER got to choose the tree (Mom retains veto power over all selections), and happily for all of us this year he picked the winner:

Jim does the cutting, and the kids do the carrying:

This tree farm also has hot chocolate and candy canes, which we all enjoy before returning to town (Monroe that is) and having lunch at the local Taco Bell. It’s a tradition that started when the kids were littler and you don’t mess with tradition.

Needless to say, we will ALWAYS have a real tree.

I’ve been teaching plant physiology or related courses for a long, long time, and one of the tenets is that woody plants don’t heal.  In contrast to animal tissues, when trees and shrubs are wounded the damaged tissues are permanently destroyed.  Wounds are compartmentalized and covered with wound wood.  Arborists are fond of saying "plants seal, not heal."

That’s all fine and good for woody plant parts, but what about grafts?  Since grafting reconnects cambial and phloem tissues, is this "healing?" And what about nonwoody plants, like annual flowers and vegetables? 

Oddly, this type of information is sadly lacking in physiology textbooks, but it’s a question that I get routinely from gardeners.  And it’s not just an exercise in semantics.  People make some poor choices in treating tree wounds, for example, laboring under the false impression that such wounds should be treated with wound paint or bandages so they can "heal."