The Garden Professors™

Ok, ‘Hot’ might not be exactly the right word, but winter in the Midwest has certainly been warmer than average this year.  I did a little trolling around on Michigan State University’s Automated Weather Network website, which has been logging temperatures and other weather variables around the state for the past 15 years and compared our current winter here in East Lansing to recent years.  Since the middle of December our average daily temperatures are 5.2 deg. F above the previous 15-year mean.  The departure from the 15-year mean is even greater (+5.6 deg. F) when we look at minimum temperatures. 

15-year average Minimum daily temperature and Current-winter daily minimum for East Lansing, MI.

Minimum temperatures are especially important when discussing winter injury to landscape plants since extreme low temps (and the conditions immediately preceding them) are often responsible for many of our winter injury problems.  With a generally mild winter and only a few, brief temperature dips below average, one might expect that we will see few winter-related plant problems this spring.  However, prolonged exposure to temperatures above average means that plants are beginning to deharden early.  We see several signs of this already; such as witch-hazels blooming in protected locations and sap in maple trees running 2-3 weeks ahead of normal http://www.michiganradio.org/post/michigan-maple-syrup-producers-say-season-extra-early-year

February 28, 2012. Witch-hazel in bloom on MSU campus.

While other trees and shrubs may not provide the same outward signs, they are progressively becoming less cold-hardy by the day.  Unfortunately, temperatures, like the stock market, rarely move in a straight line. Here in mid-Michigan, temperatures in the single digits are possible throughout the month of March.  Given the preceding mild conditions, a sudden, severe cold snap still holds the potential to cause considerable damage to developing buds on trees and shrubs.  This type of late from damage may be evidenced by shoot die-back, bud-kill or death of newly-emerging shoots.  As always with winter injury, the final result won’t be known until late May or early June. 

I ‘like’ American Forests page on Facebook so I receive their periodic updates.  One item that caught my eye recently was a profile article on Dr. Greg McPherson, who is an urban forestry researcher with the USDA Forest Service in Davis, CA.  Even if you don’t recognize the name, if you have even seen any statistics on the economic and environmental benefits of trees in cities (energy conservation, carbon sequestration, etc), they probably cited information for McPhereon’s studies, either directly on indirectly,

http://www.americanforests.org/magazine/article/forest-frontiers-greg-mcpherson/

What really made me say “Amen, brother!” in the American Forest piece was McPherson’s response to the question, “What’s the biggest issue in urban forestry today?”  His reply, “Moving from the tree-planting paradigm to the tree-performance paradigm.”  Let’s face it, tree planting, for want of a better term, is sexy.  It’s relatively easy to raise money or get politicians to show up for a tree planting event and throw a few scoops of dirt with a ceremonial silver-plated shovel while the local media cameras are clicking.  

Image: Stephen Simpson/London News Pictures

But who is going to get excited about maintenance pruning? Or developing workable tree ordinances?  Or a pest management program?

Image: Susan Lesch

I’ve participated in various tree planting programs and it always gives me mixed emotions to hand out tree seedlings to second graders.  I’m glad they’re excited about getting a tree but also realize most of the seedlings that those 7-year-olds are running with will have the same lifespan as a goldfish that comes home in a plastic bag from the county fair.  Does this mean we should ban tree giveaways or planting events?  Of course not. Even if only a few seedlings survive the grubby hands of second-graders, that’s a plus and building their awareness of trees and their environment is the bigger issue.  But we also need to build public awareness of what it takes to maintain the urban forest and accrue all those benefits on the long term.  And most of those activities don’t make good photo ops or video clips for the local TV news.

In some places, we’re starting to get the message.  Here in Michigan our Department of Natural Resources awards Community Forestry grants.  The program will fund various activities but many grants are for tree planting.  If the application is for tree planting, the applicant must include a description of the maintenance practices that will be used to ensure the long-term success of the planting – forcing applicants to think about what happens after the trees are planted.  In addition the program also requires that applicants plant a diversity of species to help reduce issues with monocultures.  Small steps, but the ones we need to take to move from the tree planting paradigm to the tree performance paradigm. 

According to a post by Paul Tukey on safelawns.blog, a recent French study which was published in the Journal of Applied Toxicology shows that corn which has been genetically modified to produce the caterpillar toxin Bt is poisonous to humans.  Furthermore, so is roundup.

Ladies and Gentlemen, we’re screwed.

The rapture is coming.  The true believers who shun conventionally produced food and eat only organic, non-GMO will be saved.  Those who don’t, well, they’re all as good as dead so don’t even bother worrying about ‘em.  Brothers and Sisters, change your ways now while there’s still time!

The end will come, not in the form of fire or water, but instead kidney failure and it will come as punishment for playing with Nature.  By messing around with that which Nature has wrought we have inadvertently created a subtle beast that now lies quietly in our bloodstream poised to destroy us.  We are the architects of our own doom and can only hope that those who survive the destruction mend their ways to bring this world back to its GMO and pesticide-free ways.  It’s our only hope.  

OK, the above statement is more than a little over the top.  Hopefully you realized that as you were reading it.  Here’s the real story.  Let me start with Paul Tukey.

I’ve read a lot of what Paul Tukey has written.  He’s a guy who’s very concerned about the amount of poison that we spray on our crops and our lawns and, to be honest, I admire his resolve, and I agree that we overuse pesticides – and to go a step further it’s people like him who are going to get people excited about reducing pesticide use and are going to make a difference in the backyards of America.    

BUT (you knew there would be a but didn’t you?) he has a habit of over-interpreting what the studies say and/or passing along information that does the same.  Usually it’s not too bad.  For example, this article about Round-up is a bit over the top and is based more on the beliefs of one scientist who is considered an extremist rather than on our best scientific data, but at least it acknowledges the fact it might be wrong.  It’s the kind of article that I don’t like, but not one I’m going to get up in arms about because then I’d be constantly up in arms and probably end up suffering from chronic migraines – there’s just too many articles like this for me to worry about all of them.

The article that I began this post discussing is different because it says, and I quote “genetically modified corn containing the genes for Bt (Bacillus thuringiensis) is toxic to humans” and then goes on to say the same thing about Round-up.  The implication is that the study which was conducted shows without the shadow of a doubt that we’re killing ourselves by eating genetically modified crops which have the Bt toxin and/or have Round-up used around them – at least I think that’s the implication.  If any of you think I read it wrong please let me know.

The idea that this study shows that we’re hurting ourselves with genetically modified crops is ridiculous (please be aware that I’m talking about this particular study — there certainly could be others in the future that change my mind).  Why you ask?  Let me count the ways.

1. We eat Bacillus thuringiensis all the time.  It’s a naturally occurring bacterium which is often present in food and is cultured as an organic pesticide which is likely to be present at some concentration in organically produced crops sprayed with it.  If you think that avoiding genetically modified foods will keep you away from it you’re sadly mistaken.
2. This study tested the effects of Bt and Round-up on a strain of kidney cells.  Hardly any Bt and Round-up gets to kidney cells even if you eat or drink them – there are just too many barriers to cross before reaching the blood stream (But it is important to note that some certainly does – just very, very little – One article I found showed a level of about 0.2 nanograms Bt/milliliter blood and about 75 nanograms Round-up/milliliter blood in a population in Canada). 
3. This study artificially placed Bt and Round-up in with kidney cells in a test tube.  Obviously nothing like a natural environment.  Try the same thing with coffee or dish soap at the same concentration and I bet you’ll see worse damage to the cells.         
4. Just to get picky, kidney cell line 293 was used.  Look it up on Wikipedia (look up HEK 293) this IS NOT an appropriate cell line to be testing poisons on.

Long story short — the article cited really doesn’t reveal much abo
ut how safe or dangerous genetically modified crops are.