Mission Accomplished, Prairie Now a Savannah

Well I've done my part!  The very cool Mast Tree Network has challenged us sign a pledge promising to plant an oak tree yet this year.  They have asked for 20 pledgers.  We're up to 5 and gaining momentum.

I just got back from planting 3 bur oak seedlings in a natural area owned by my kids' elementary school and managed by an amazingly dedicated group of volunteers.  Part of the natural area is a gorgeous tallgrass prairie:

Somewhere amidst that sea of grass there are now three tiny bur oaks, which Aldo Leopold called the stormtroopers of the prairie:

OK, that probably doesn't look like a stormtrooper to you, but I'm telling you this little dude is fierce.  Here's the back story on these three trees.  I gathered the acorns last fall from beneath three massive bur oaks on the gorgeous campus of Carleton College (yes, there is terrific fishing in those ponds, but please don't tell anyone).  Many of those acorns were eaten last winter (which explains the clarity of my thinking during that time frame and the quantum steps I made in my career!), most were planted this past spring, and some languished in the fridge well into the summer.  They didn't stay in the fridge for the sole purpose of annoying my wife, Alice, but that was the practical effect.  It's just: how can you throw acorns away?

Then to prove to a friend in the nursery business that I could plant acorns in pots ridiculously late and still grow bigger trees than he had starting from acorns early in the spring, I planted them on July 16.  I have shown you what the English oaks that I also planted on that date did; one of them, in a prototype tree tube, reached 15" after only emerging from the soil on August 1.  The bur oaks were slower to germinate, and didn't grow as much - in part because the acorns weren't the size of golf balls like the English oaks giving them a supercharged dose of early carbs, and in part because they were in a shadier spot than the English oaks.  Still, they did very well; the one in the prototype grow tube reached nearly 10 inches.

Most importantly, at least to me, is that my oaks planted late in the season ended up as big as my nursery manager friend's spring planted oaks.  Braggin' rights!  I was even more impressed with how much root development happened in the short period of time since July 16.

And no, I did not leave those little stormtroopers out there naked and along to fight their way through the prairie grass and the deer, who bed down just feet away from where I planted and who are now regular visitors on our old residential street several blocks away.  They are safe inside plastic tree tubes.  We watched Apollo 13 last weekend, and as I lowered the tree tube over the seedling I couldn't help thinking of it as an oak launcher.  I'm already counting down until spring when I can say:  Houston, we have lift off.

Choice acorns, hand selected from amazing parent trees, and planted within 2 miles of their source as part of a savannah restoration.  That's a rewarding afternoon's work.  Thank you Mast Tree Network for being my impetus!

Minnesota Bound Clip: Oaks & Air Pruning Pots

The second of three short clips aired on Minnesota Bound this past Sunday evening (and will repeat this coming Saturday) on KARE-11 here in the Twin Cities. (Click on the link to view - it's the "Rapala Almanac" segment right after the piece on smallmouth bass fishing. Which, by the way, I'd rather be doing right now!)

The theme of this piece was planting, especially in light of the massive removal and replanting effort we will soon be facing here in Minnesota as new Emerald Ash Borer hot spots keep popping up. My two pieces of advice:

1. Plant oaks - There are of course myriad reasons to plant oaks, but one of the main reason people don't plant them more often is the widespread perception that they grow too slowly. Overcoming the slow growth stereotype is surprisingly difficult, seeing as how it's patently false. Hopefully this segment will help, if only a little

2. Look for trees grown in air pruning pots - The nursery industry is finally starting to pay attention to root systems. The life span of urban trees planted in the 70s and 80s in the wake of Dutch elm disease has been abysmally, embarrassingly short. The primary reason: nursery and planting practices that mutilated root systems. Traditional plastic nursery pots tend to promote a circular, spiralling root growth pattern. After planting those spiralling roots continue to grow in girth around the main trunk, slowing growth and ultimately killing the tree. The tree literally strangles itself (think of giant pythons wrapped around the base of the tree and you've got the right idea).

Air pruning pots come in a variety of designs, but the concept is the same. Openings in the walls of the pot expose root tips to air, causing them to stop growing outward and forcing them to branch out. This creates a thick, fibrous root system and prevents spiralling or girdling roots.

Where can you buy trees grown in air pruning pots? Here's one place: Knecht's Nursery here in Northfield, MN. Owners Leif & Deb Knecht are great people and have what I have come to admire most in people: a willingess to rethink the way they do things, a desire to find better practices, and of course a deep and abiding love of trees!

Brilliance & Stupidity In 1970

Reader David Olsen send a link to this fantastic article, published in the October 21, 1970 Salt Lake City Deseret newspaper.

The brilliance: The article describes work with hybrid oaks done by Walter P. Cottam who had "retired" as a botany professor 8 years before in 1962. (One is reminded of Dr. Charles Burnham who, as a supposedly Emeritus professor of agronomy went to his University of Minnesota office every morning at 7am and who oh, by the way, founded the American Chestnut Foundation in his "retirement.")

Cottam is thought to have been the first person in American to successfully hybridize a member of the white oak group, turbinella oak (aka Sonoran scrub oak), with a member of the black oak group, Texas post oak.

More fascinating to me is Cottam's work with turbinella x Gambel oak hybrids. Utah Fish & Game biologist Rudy Drobnick identified a naturally occurring stand of hybrids in the Salt Lake Valley in 1954. Here's the interesting part: Q. turbinella is not native to that part of Utah! So how on Earth could there be a naturally occurring stand of hybrids? Drobnick and Cottam determined that 7,500 years ago, during a period of drought and elevated temperatures (yes, there were periods of elevated temperatures in the past ;-) turbinella oak migrated northward and in some cases crossed with Gambel oaks. When temperatures cooled, the purebred turbinellas died off in that area, but the hybrids survived (and reproduced - there's that question again of what defines a species).

I'm always amazed by people who can identify stands of naturally occurring hybrid oaks, because the range of characteristics for leaf shape, bark pattern, branching, etc. is so great within each species it takes an incredibly keen eye to notice trees that clearly exhibit characteristics of two different species.

But then again, I'm getting less and less amazed by this talent every day, and more and more convinced that many (most?) of the oaks we see in nature are, at least to some degree, a hybrid.

The stupidity: Cottam had planted his hybrids on the university campus for years, but had recently been stopped by a blanket ban on planting anything less than 6 feet tall. Plus, grounds crews spraying 2,4D to kill dandelions had sprayed some of his cross pollinated trees, causing the acorns to abort... Two years in a row... Second generation trees Dr. Cottam had been waiting eight years for!

Eight years is a big deal for any of us. For the 76 year old Cottam it was a VERY big deal. Like all tree lovers, his mind was filled with experiments he wanted to perform and trees he wanted to try growing... and by an acute awareness of his own mortality. I love this line: "I was a darn fool for starting this. I can't finish it. We have a lot more crosses we want to try. We haven't even scratched the surface."

The question is: Did anyone continue his work? I'll look into this. The answer, as in the case of Helge Ness at Texas A&M and all too often, is probably not.