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!

Friday mystery revealed!

Good sleuthing over the weekend!  As John, Karen, Jimbo and Al suggested, there is something stuck on the side of this Norway maple (Acer platanoides, which is Latin for “maple that takes over the planet”).  In fact, the reason that I, with my pathetic ID skills, know that it’s a Norway maple is because it’s a nursery tag stuck in the tree:

This type of injury really bugs me, because it’s entirely preventable.  One of the cardinal rules of transplanting trees and shrubs is to remove all foreign material.  And this is a perfect example of why.  I don’t know the history of this tree, but this is was I think happened.

The tag was on a branch of the young tree; as the branch increased in girth, it became girdled by the plastic and died back.  At the same time, the girth of the tree increased to encompass the base of the branch and the tag.  The dying branch was either torn from or broke off the trunk, creating a tear in the bark and creating the horizontal scarring at the base of the wound.

If you’re hopeless with plant names (like I am), keep an electronic database of all the plants you’ve installed in your landscape, including the name, the date installed, and any notes, especially for failures (e.g. not cold hardy enough, invasive, too large, slug snack, etc.).

Friday mystery photo

Today’s photo is courtesy of Photoshop technology.  I’ve edited the damaged area so you can’t see what caused, or at least contributed to, the damage:

Now before you complain that I’m cheating (which I am!) keep in mind that what I edited out could have been removed before you were asked to diagnose this injury.  I will tell you that it’s not due to pests or disease.  As is so often true in real life, there could easily be multiple correct answers.  On Monday I’ll provide an untouched photograph and rail against the all-too-common practice that can cause the damage.

Have a great weekend!

Friday puzzle solved!

Lots of brainstorming over the weekend, and all the answers were legitimate.  A few people came close with the observation that the roots looked like they had grown over something.  And that’s exactly right:

This is a great example of nurse log decomposition.  When the tree on the right first began growing (and it could have been decades ago), it sent lateral roots out, over, and around the nurse log to reach the soil.  As the nurse log degraded, the tree’s roots were left high and dry, outlining the girth of the original log.

Does this natural example have application in managed landscapes?  Absolutely!  As several of you pointed out, removal of soil or organic matter by erosion or decomposition can leave woody roots exposed.  If these roots are injured by feet or tools, they can lose their bark and become open to disease or pests.  These are the structural roots of the tree, and if their stability is compromised, so is that of the tree.

(Though this tree has had some injury to its roots (probably from hikers), it’s unlikely to fail as it’s pretty small. )

Friday puzzle

Finally – something else to do rather than post to the IAL blog!  On to today’s photo (and I apologize for its blurriness).

The tree in this photo is alive, and as you can see has structural roots perched well above the soil.  How might this have happened?  There are multiple possibilities.  And secondly, is there a negative impact on the tree, and if so, what?  Answers and another photo on Monday!

Have a nice weekend! 

My Favorite Drug

I love coffee, but I’m not a big coffee drinker.  On average I probably consume a cup of coffee every week or two.  Why don’t I drink it more often?  For a few reasons: First, I’m too jumpy/jittery/nervous to begin with and I don’t need this stuff making it worse, second, it tends to upset my stomach if I haven’t had a meal beforehand, and third, while I like regular coffee, the stuff that I really love are those insane fru-fru coffee drinks that you can only get at specialty shops for five or six bucks — which seems like a waste of money to me.  As you may have guessed, at this very moment, I have an overwhelming urge for a vanilla latte and so, in lieu of that, I have decided to submit this post.

Anyway, as most of you know, coffee is a horticultural crop, and so are most of the other sources from which most of us obtain our (legal) chemical stimulants like chocolate and tea.  What most people don’t realize is that the stimulants in chocolate and tea are actually somewhat different than caffeine.  Chocolate does contain some caffeine, but its major stimulant is the closely related theobromine (which doesn’t actually have any bromine in it…).  Tea (which also has very low amounts of caffeine), on the other hand contains the stimulant theophylline which is, again, closely related to, but not the same as, caffeine.

What blows me away about caffeine is how toxic it is.  If caffeine were a pesticide it would need to be labeled as category 2 (there are 4 classes with 1 being the most toxic).  Its LD50 (in other words, the amount of this chemical that, if fed to a person, would have a 50% chance of killing him/her) is estimated at about 75 milligrams per pound that a person weighs.  According to Starbucks website, one of their tall vanilla lattes contains about that much caffeine, and so you could assume that a 150 pound person could kill themselves by drinking about 150 lattes (or 150 of the smaller cups of espresso from which the coffee is made).  Additionally, though findings are inconsistent, caffeine has been linked to certain cancers.  The current thinking is that it may affect hormone levels in the body which, in turn, influence hormone related cancers like breast cancer, etc.  This research is far from conclusive, but it is concerning.

OK, so here’s the thing that’s interesting to me.  There is a small but real contingent of people out there who want to ban the herbicide 2,4 D (I picked 2,4 D randomly – I could have picked Round-up,  Sevin, or any other pesticide – but I was thinking of summer, and so 2,4 D, the most commonly used turf herbicide, is what I chose).  I’m no fan of 2,4 D and would love to see it used less frequently than it currently is, but it is a useful herbicide, particularly in the production of grassy crops (like corn).  In lawns its overuse borders on the insane.

Opponents of 2,4 D would like to see it gone, in large part, because of its toxicity and potential to cause cancer.  And, indeed, there are some studies that show that 2,4 D has the potential to cause cancer, though these findings are inconsistent and ultimately inconclusive.  Additionally, in terms of 2,4 D’s LD50, it’s about 170 milligrams per pound that a person weighs – over two times LESS toxic than caffeine.  I’m not going to bother figuring out how much 2,4 D would be in an average glass of 2,4 D because, well, I’ve never been served a cup of 2,4 D before and hopefully I never will.  (If you’re curious as to how much 2,4 D would be in a cup of spray if you scooped it right out of the spray tank — then about 50 mg is a good estimate though it could be higher or lower depending on a lot of factors).

Anyway, this leads me to a ton of further questions, the most important of which is, without doubt, do anti-pesticide activists who fear the health dangers posed by 2,4 D drink coffee?

For those of you interested in these types of questions I encourage you to look over this article: http://www.marshall.org/article.php?id=73  It is posted on the website of a conservative group (which will probably alienate some of you and make others happy) – but it was originally published a number of years ago in a well respected journal and is one of my favorite articles ever in terms of getting the old brain thinking (Please don’t get the idea that I agree with everything in the article – I do not).  Bruce Ames, one of the authors, is what we call in academia a “heavy hitter” and so, even if you don’t agree with what he says, his words are well worth reading.

The Fun Never Ends Here At Garden Professors!

I have another post to toss up later today, but first I thought I’d direct your attention to the comments on a post from a few days ago — The post titled International Ag Labs – who are they and what do they do? It’s fascinating to see so many people discussing the benefits of IAL (and more fascinating to read their comments…some of which are thoughtful and some of which are….less thoughtful).  The reason that there are so many of them is that IAL apparently sent out a blanket e-mail to their customers to try and get them to respond to Linda’s post.  This is absolutely fantastic!  I never imagined we would receive so much free publicity!

Interestingly enough I’ve been informed through a semi-reliable source that they (and the truth is that I’m not exactly sure who “they” are) want to try to get Washington State to shut our website down!  Again, awesome!  This will result in even more publicity!  We might even get into the papers!

At this point it’s probably worth telling all of you what I think about IAL based on their tests and recommendations.  Their tests look fine — not the format that I’m used to, but no big deal.  Their recommendations, on the other hand, seem silly and ill advised to me (I’ve been working with soil tests to one extent or another for about 18 years now).  That doesn’t make them wrong, but the accepted science currently out there doesn’t support them.  Also, I can’t stand it when a supposedly independent lab seems to be promoting particular products — in my opinion that could, potentially, compromises their objectivity.  Look, if you want to believe in a particular method of growing plants then that is your right — far be it from me to dictate your belief system — but, as Linda once wrote to me in an e-mail, that is faith based growing.  On this blog we talk about and support science based growing.  Faith based growers are always welcome here, but be aware that you probably won’t be happy with everything we write.

Friday turf troubles

To no one’s great surprise by now, the white substance in Friday’s photo is mesh:

Like so many “instant” lawns that never really establish, the original grasses in this sod have died, leaving only weeds, debris, and the netting used as a matrix to support bunchgrass production.

(I have a personal grudge against sod netting, having removed the tenacious remains of black plastic netting when we replaced our lawn with alternative groundcoverings.  Like Velvetta and Twinkies, this stuff never dies.)

Friday puzzle solved…finally

We’re back to civilization, so I can finally post the answer to the puzzle.  I’ve been without cell service and our only computer access was dial-up at a glacial 37.2 kbps.  Yes, kbps.

Back to our puzzle.  Here’s a larger version of Friday’s photo:

It is bark, as many astute readers pointed out.  As far as I know, it’s a London plane tree (Platanus), but given the promiscuity of the genus, who knows exactly what species or hybrid it is?

Other tree species were suggested by others and I immediately Googled them to see what their bark looked like.  Check out Pinus bungeana (thanks to @Garden Hoe), Parrotia (from Deirdre), Smilax bona-nox (Bryn), Stewartia (one of Deb’s hedged bets), and Corymbia maculata (from Jimbo).

And now, thanks to Ed, I will forever look for pictures hidden in bark.  Someone should make a “Gardener’s Rorshach test” from variegated bark!