Tags » Trees


Tree Planting 2010

Categories: Landscape, Trees

Of all the work we do here in the landscape department, some of the best is the tree planting.

Think of our landscape at Middlebury as a living organism, changing and evolving. Trees have a lifespan, like us, only measured not in decades but hopefully in centuries, for the best and strongest. Site vagaries not withstanding, most species live for a similar amount of time.  A mad rush of planting one year will mean that down the road a large hole may develop in the landscape, as the same aged trees all need replacing at the same time. Take, for instance, some work being done at Utah State University.

The main quad at Utah State is lined with 80 year old Norway maples, which in Utah live about 60-80 years. Plans are underway to replant the green, and to remove the Norways before they fail. This has met with some resistance, probably based more on disappointment, as the look of a beloved quad radically changes in the space of a couple short years.

We started our tree planting this year on Arbor Day, thanks to Hilary Platt and Chelsea Ward-Waller, two of my students from Winter Term, and the driving force behind getting Middlebury to become a Tree Campus. Many students helped plant trees around Bi-Hall, and near Coffrin. The focus for this area was to help define some of the space around Bi-Hall Park, as well as planting in between Coffrin and Bi-Hall to help with storm water abatement. We used Sweet Gum there, Nyssa sylvatica, and a variety of other native trees nearby, such as Hop Hornbeam, Scarlet Oak, Red Oak, and Ohio Buckeye.

Chelsea and Friends planting

More friends planting

The second focus of tree planting this year happened later, after the rush of commencement and reunion. I enjoy this so much so I almost don’t want to tell of it.

Part of a happy and sustainable campus landscape involves diversity. Having as many different species of trees as possible ensures that should the next insect (Asian Longhorn Beetle, Emerald Ash Borer) or disease come to campus, large sections of our tree population won’t get wiped out, like the aging Norway maples at Utah State.

So I prowl nurseries and garden centers, looking for healthy plants that will do well on our campus. With such a varied landscape, it isn’t difficult to find a spot to tuck in some type of tree somewhere. We focused this year on areas of the campus lacking in tree color, and used ornamental flowering varieties of trees to liven up otherwise very static green locations. An example of this is a small section of lawn right to the north of Painter Hall.

While not a large area, comparatively, it was large enough for three small flowering trees, set in a triangle. One was a Butterflies Magnolia, small yellow flowers in early spring. Later in June will come flowers from the Yellowwood nearby, followed by a small tree in bloom now, a Heptacodium, Seven Sons Flower. More on that species in a later post-it’s spectacular.

Other areas planted include North of Warner Science, where many over-mature Sugar maples are slowly showing the effects of time, as well as along the east side of Hepburn Road, and North of Gifford.

Hoopsii Blue Spruce north of Gifford

Paperbark Maple north of Gifford

Maackia amurensis north of Stewart

Other fun varieties planted were a “Discovery” hybird Elm, Red Obelisk Beech, “Katsura” Japanese Maple, Kousa Dogwood, and Yellow Birch (the kind they make Birch Beer from). 4 Different varieties of Magnolia were planted, one red, one pink, and two yellow. In all, 32 trees have been planted so far, and a couple more are still on the way. The Tree Karma count? Not exactly sure, with all the storm damage, but I’m thinking it’s still holding at 3.5 to 1 or so.

Big Huge Icky Giant Tar Spot

Categories: Insects and Diseases, Trees

Giant Tar Spot

The study of plant diseases made me terribly depressed in school, but also made me laugh on occasion. I imagined two plant pathologists walking around, looking at sick leaves. Of course, each of them wouldn’t admit to the other that they didn’t know or recognize some strange disease, so they’re making up names as they go along. Strange fungal spores on a cherry tree? Well, it looks like Black Knot, and the disease is named.

A fall arrival on campus (and occasionally in my inbox as a question) is always the blatetenly named Giant Tar Spot. (“Hey, what’s this?” “You don’t know that? Any idiot knows thats, um, Giant Tar Spot. Yeah, that’s it. Giant Tar Spot”) You guessed it, huge jet black spots on the leaves of primarily Norway Maple.  This, too, is a fungus, Rhytisma acerinum for you latinally inclined. It infected the leaves way back in early summer, but they don’t really show up until now. When it’s too late to treat.

Not that you need to. Late diseases and insects like this look terrible but, let’s face it, the leaves are only around for a couple of more weeks anyway. It’s not a bad year for it this year on campus, we’ve had it much worse. If you’re looking to get rid of it on your tree at home, rake and dispose of the trees at your neighbors…

The Plums are (nearly) ripe

Categories: Trees

I may be risking excommunication.

The landscape department, probably like many others across campus, has its share of secrets, little things nobody else knows about. My inside mole at the Grille keeps me updated when the linzertorte cookies are around. The view from the Bi-Hall roof after a snowstorm is spectacular. And, there’s a pretty spectacular plum tree on campus.

Plums are in the Rose family, the genus Prunus, which it shares with Cherries, Peaches, Apricots, and Almonds. The full latin name of the plum is Prunus domestica, The latin genus stolen from the greek word προῦνον (prounon), and the specicies domestica from the botanists term for “such a long and muddled history of hybridization we can’t possibly straighten it out”. It is no exaggeration to state that plums have been cultivated for thousands of years-Pliny the Elder writes of Apricots, stating them to be a type of plum, and a 6000 year old apricot pit was found in an archeological dig in Yerevan, the capital of Armenia. The earliest Prunus appear in the fossil record in the middle Eocene, about 45 million years ago.

Our plum is one of the first trees to bloom on campus, at about 80 degree days. In a good year, about 50% of the blossoms are pollinated, and bear fruit. Dry condidtions in the late spring will cause the fruit to drop while still small, and overly wet conditions are prime for Brown Mold, as unattractive as it sounds. Most plums are covered in a white waxy coating-this is a epicuticular wax that protects the fruit from UV light and also repels water.

There are many cultivars of plum. I’m betting, though, that our plum is a popular (and hardy, fortunately) variety known as Stanley. It’s a beautiful blue-purple color, with a golden meaty center, surrounded by a small pit. It was bred in the New York State Agricultural Experiment Station, part of Cornell University, located in Geneva. The station is  the mecca of hardy fruit hybridization, and brought us the Empire and Cortland apple. Stanley is literally the plum all others are now compared against. Richard Wellington developed the Stanley plum in 1926-when he started at the station, there was estimated to be 1 million plum trees in the state of New York.

Plums have a greater variety than other tree fruits, coming in many colors, sizes, sugar contents, and textures. They are an excellent source of anti-oxidants, more so than tomatoes, bannanas, apples and oranges. Marketeers are busy trying to sell us “dried plums”, hoping we forget grandmother’s name for them, the evil and dreaded prune. A sugar plum, aside from dancing in your head, is by law a plum with greater than 20% sugar content, at least according to the California Tree Fruit Agreement.

I enjoyed selling plum trees in my retail days. I was forever talking customers out of apples, as they aren’t really a tree as much as a pet, requiring greater care than anybody realizes. (Leave the apples to the experts-there is sanity in bulk) Plums, however, are carefree, without the serious pests and diseases of other tree fruits, and are self fertile, meaning one tree is all you need. Stanley should be hardy in most of the Champlain Valley, with perhaps the occasional late frost nipping the buds.

Oh yeah. I forgot to tell you where the tree is.

Lightning Strike

Categories: Trees, Weather

Our wild and crazy summer weather here at Middlebury continues, this time with a tree being struck by lightning. (Side note to the faithful readers out there. I feel for you-has this blog been getting depressing lately? With vandalism, more vandalismstorms, more storms, even still more storms, and disease,  it seems like the Middlebury Landscape is getting tragic. Hold the faith! We’ve been planting as well. Posts coming soon on this year’s tree plantings, as well as a new look for Pearson Hall.)

Ginkgo at 121 South Main

The tree hit is a Ginkgo ( read here if you’ve forgotten about them) located in front of one of Middlebury’s “outside” houses, near Public Safety at 121 South Main Street. I don’t know the night it got hit, but it was brought to my attention by one of the diligent members of our crew. Looking at the tree originally, I first thought the tree had just cracked down near the base, possibly in some strong wind. The tree shows what arborists call co-dominant trunks, where two trunks of equal size meet and grow together. This is frequently a recipe for disaster, as a bad union often results, where included bark makes a weak joint, and the two trunks typically fall apart away from each other.

Co-Dominant Trunks-click for a larger view to see the wound

I called an Arborist friend to consult on the damage-this is one of our favorite trees in Facilities, many of us would mourn the loss. His skill, knowledge, and experience led him to look up the tree, rather than me just jumping to the first obvious conclusion, and that was how he discovered the damage around the cable up top, as well as noticing the toothpick sized wood pieces scattered around the yard, small pieces of trunk blown away from the tree from the force of the lightning. Being tree geeks, we climbed up to investigate.

Damage around one the cables

Damage on another limb-the lightning jumped to this branch

Trees are frequent targets of lightning. Standing alone, frequently taller than many buildings around them, many trees get hit each year. Lightning is fascinating all on it’s own, with their impressive 100 million volts and  temperatures greater than 50,000 degrees fahrenheit. 16 million lightning storms are estimated worldwide in a year, and measuring instruments record over 100 million strikes in the U.S. each year, killing on average 90 people. They even get their own phobia, Astraphobia, fear of lightning.

The conditions needed for lightning are still debatable, but should those conditions exist, negative ions accumulate at the base of the storm clouds, while positive ions pile up on the ground. “Stepped Ladders” descend from the clouds, while “streamers” arise from the earth, typically strongest from the tallest structures, such as buildings or trees. Should they build strong and fast enough, they meet to form a lightning bolt, and this electrical discharge super heats the air around it to 36,000 degrees fahrenheit, compressing the air creating supersonic shock wave we hear as thunder.

When lightning strikes a tree, the sap in the tree boils, turning to steam and blasting the bark away from the trunk. The electrical charge flows through the tree, exiting out the root system, which could be severely damaged in the process, sometimes with no visible sign above. In most cases, though, a strip of bark is torn from the tree, often in a long strip, but sometimes, like this ginkgo, only above and below. Trees with only one crack tend to close the wound and suffer, yet live, while trees with wounds on both sides of the trunk are frequently killed outright. Obviously, even a wounded tree can die from secondary reasons, such as insects and diseases, less able to fight them off.

Trees vary in their susceptibility to lightning strikes, possibly for biological reasons, or possibly simply because of their height. Elms, Oaks, Black Locust and Ash tend to be very susceptible, while Beech, Horsechestnut, and Birch tend to not be very susceptible. It may be the starch content of the tree making it more susceptible, while resinous trees are poorer conductors.

So there is hope for our Ginkgo. The wound at the bottom was traced, where loose bark is peeled away carefully from the trunk to the point where it attaches again. The thinking with bark tracing is that loose bark can trap moisture and disease, so by removing it the wound can dry better. Maybe it’s just something to do to make arborists feel not quite so helpless…

Lower wound after tracing

Lower part of wound where lightning went to ground

The cabling up in the crown of the tree is a little more problematic. Originally put in place to help stabilize the two co-dominant stems, the system now obviously cannot be trusted, as the wood surrounding the bolts holding the cable is now dead. We decided to replace the cable with two others, one above the old cable (a better location from an engineering perspective), but also one looser below, in case one of the stems fails completely at the original cable site, and breaks. The tree will then still be braced by the lower cable.

Placing the cables in the tree

The three cables in place

So now, we wait. The rest of this year, and into next spring, will be the crucial time, and when we shall see just how bad the strike was. Should it still appear somewhat healthy next spring, we will aerate the soil around the tree, add compost, fertilize, and mulch. Hard to imagine now, but, if we get a little drought this summer, we’ll even go down to water.

When Good Plants go Bad

Categories: Insects and Diseases

My most depressing year at the University of Vermont would have been my junior year. All plant and soil science majors took Plant Pathology that year, two semesters worth. For all of you non-science plant geeks, plant pathology deals with diseases of plants-basically anything except insects. Virus, fungi, bacteria, even abiotic problems were addressed. After a year of learing the various ways plants die, I remember thinking about the hopelessness of it all, wondering how on earth plants even existed.

Insect pest management was the previous year. Insects, while a pain, can very often be sprayed, attacked by other bugs, or even crop rotated away. But most of plant pathology? Hopeless. At best, they are “controlled”, like most fungicides, at worst, well, here’s a list of plants if you have to replant that may not get that disease. No magical sprays, potions, or elixirs to help you along. Often the best defense against many of these problems is simply a good offense-a healthy thriving plant will suffer some little indignities here and there, but will fight on.

The recent spate of warm and wet weather has Verticillium Wilt  rearing its nasty little head around. I’ve gotten several emails about it recently, and am expecting more. Verticillium Wilt is a soil borne fungus that enters the roots, then both produces toxins and spreads spores throughout the xylem (water tissues) of the plant. The plant, in a bit of idiotic self defense, uses various compounds to plug the xylem further, ostensibly to stop the spread of the  fungus, but further restricting water movement inside. The name wilt is a descriptive, as the first symptom typically seen is the last, as the leaves wilt and die from lack of water.

In fruit trees, the fungus is called Black Heart, commonly seen in Apricots, but is also seen in many types of plants, such as potatoes, tomatoes, mint, and many types of trees and shrubs. The fungi, Verticillium albo-atrum or V. dahliae, can persist in the soil for up to 15 years, forming small black resting structures activated when roots grow near them.

On campus, Verticillium wilt is evident on some older plantings of lilacs, like on the picture below. This particular clump is near Battell, on the wetter, or beach, side. Lilacs don’t like wet feet (roots) to begin with, and this may help bring about the fungus.

Lilacs at Battell

Verticillium symptoms on Lilac

Another victim of Verticillium seems to be a Catalpa, know by my kids as the Green Bean tree, for the size seed pods it produces. Spectacular in flower, this tree was the subject of my first Twitter picture about a month ago. (Are you following Middland on Twitter? I’m having a blast posting pictures of plants in bloom around campus, I’m at http://twitter.com/middland.)

Verticillium wilt in Catalpa

The location is directly across from Emma Willard, blocking one of the special sightlines at Middlebury, that of the view from the front of Emma Willard looking up towards Old Chapel. While I mourn the loss of all trees, more than one person has lamented the unfortunate planting location of this tree, wishing it were elsewhere. This loss is particularly wrenching for me, as I watched it come down with this disease last year, but then watched it leaf and flower out again this spring. Thinking Verticillium more quickly virulent, I had false hope this spring, and now know better. Fortunately, the next nearest tree is a birch, resistant to Verticillium, so this loss should be confined to a single tree.

Wilting leaves on Catalpa

Another Day, another storm

Categories: Trees, Weather

The storms certainly keep coming, and, worryingly, the trees keep succumbing.  Today at 3:30 a very brief but intense cell blasted through campus. We’d lost power for a little bit, I don’t know why. The weather station recorded about 1/4″ of rain in 15 minutes, with a peak wind gust of 35 mph, from the north. This was enough to take the life of a poor Hackberry tree.

Hackberry by Warner Science

This poor tree had been scarred at the base years ago, maybe by a random mouse, maybe by something mechanical. At any rate, the worst place to wound a tree is right at the base. A tree has a very hard time compartmentalizing the wound at the base, and structural integrity of both trunk and root system is compromised. Look at the picture below-the wound was on the north side of the tree. The roots rotted away on that side, and the strong north wind gust toppled the tree right over.

Base of Hackberry

I took these pictures on my way home at 4, but I would imagine the rest of the campus trees are fine. A perfect wind knocked this one down. I’ve already got a replacement in mind.

EDIT: Middblog just posted some YouTube video of the rain here-it’s impressive.

If a Tree Falls…

Categories: Trees, Weather

I’m not much of a Twitterer, although I’ve been called a twit many times.I don’t want to get tweets on my cell-my phone vibrates so violently at the slightest ring or text message that while weeding I end up shrieking like my 10 year old thinking I just weeded a bee’s nest. But I do check some from time to time, MiddBlog being one of my favorites, and they cross-tweeted (is that the right phrase?) a posting from Audrey Tolbert, who with Cody Gohl are blogging their Middlebury summer. (They are going to learn the Vermont secret-we put up with winter for the summer. Not too hot, not too sticky, and, so far this year, not too buggy.)

Anyway, she posted a picture asking“If a tree falls in Midd and there’s no one on campus to hear it, does it make a sound?”. Yes, Virginia, it certainly does.

Silver maple-Hillcrest Road

Silver Maple-Hillcrest Road

This is a Silver Maple tree behind the Chellis House. The storm I reported on last week, well, this was one of the trees that fell over. The picture does not do the size justice, as the trunk of the tree was at least 4′ in diameter. Look carefully, you’ll see about 1-2″ of live wood around the trunk, and the rest was hollow.

Close Up of trunk

One of the surprising things about this tree falling was its aim-it fell in absolutely the perfect direction, missing the woodline separating Hillcrest Road from Adirondack Road, missing Chellis House, the Queer Studies house, and the garage next to Chellis. We couldn’t have asked for anything more.

I wasn’t going to write about this poor tree. I am actually embarrassed by this. While I knew the tree had structural problems, I had no idea the extent of the damage inside the trunk. Look at the close up picture-those are weeds growing between the main stems at the top of the trunk. Large trees like this will often collect leaves there, and eventually grow things. It is the trunk decay that is surprising, and I feel like I should have known about this problem. Two arborists I respect both looked at this tree, though, and said that I had no way of knowing how bad it was, that they see this all the time, one going so far as to say “this is what Silver maples do.” So they made me feel a little better, and now I’m not blushing in embarrassment posting these pictures.

This tree is now cleaned up and gone. We’ve caught up on most of our storm damage, thanks to some very hard work by our landscape department and some excellent outside contractors. The elm I wrote about below Mead Chapel is OK, although more bare now. Once the hanging branches were pruned out there was more left of the tree than I had first thought, so that’s good. Many of the elms had some broken branches here and there, and a handful of other trees on campus had a branch or two break. Overall, not as bad as it could have been.

Black Locust

Categories: Trees

There is an area of campus called Stewart Woods-it’s south of Stewart Hall, on the other side of the road, next to the graveyard. Our department mows underneath the trees, forming a beautiful little grove next to the road. The trees are black locust, Robinia pseudoacacia, and are in full bloom right now. A favorite of honeybees, walking over there you can just hear the air humming with the sound.

Stewart Woods in bloom

Stewart Woods in bloom

Native from Pennsylvania to Georgia, west to about Oklahoma, early settlers have since dispersed the tree far and wide. Like the lilac, old house and farm sites in Vermont can often be found by the black locust trees nearby. They had multiple uses back then, and still would, were it not for the locust borer, a destructive insect wiping out nearly all the magnificent trees in the prime of their life. The trees grow in groves, suckering up from their roots, making sharing trees with your neighbors easy. (This is like a lilac as well-popular early colonial plants were easy to propagate.) The wood was used not only for burning, with a very high BTU, matching an equal weight in coal, but also for fence posts, nearly never rotting when in contact with the ground. In fact, Donald Peattie in “A Natural History of North American Trees” quotes mark Catesby, a British naturalist who visited Jamestown a century after it’s founding. He states “they erected each of their little hovels on four only of these trees ( the locust tree of Virginia), pitched into the ground to support the four corners; many of these posts sare yet standing, and not only the parts underground, but likewise those above, perfectly sound”.

So, apparently, no “log cabins” for our early settlers, but an impressive grasp of the semi-colon.

The latin, Robinia,  honors either Jean Robin, or son Vespasien, who grew seeds of the tree sometime between 1601 and 1636, and introduced the tree to France, where it became all the rage. The wood is so strong, it is also used for nails on ships, lasting longer than the hulls they held together. The British used the superiority of our hastily built “locust fleet” as an excuse for their defeat on Lake Champlain in the war of 1812. The nails, also called Trunnels, took advantage of the nature of Locust wood, that when wet it expands and becomes leak proof.

Peattie expands the tree nails story, writing of William Cobbett, a famous English publicist and economist, who between 1917 and 1819 started a Black Locust grove on his farm on Long Island, hoping to supply the British navy with tree nails. He had to hurridly leave what he undoubtedly still called the ‘colonies’, having been chased out by popular opinion for libeling Dr. Rush for having killed George Washington by malpractice. He returned to England with some Black Locust seed, and the corpse and coffin of Thomas Paine, planning to re-intern the body in a spectacular monument to atone for his former attacks on the author. He never finished, the coffin auctioned to a furniture dealer, the corpse inside lost to history.

A special strain of Black Locust used to be described as “Shipmast Locust”, having perfectly straight and clear trunks for many feet, yielding valuable timber. It used to be described as a separate species, until botanists yelled foul, merging it back with the normal Locust, as it was probably just a cultivar asexually propagated by root suckers.

The tree itself grows fairly straight, only branching at the top. The leaves are a nice light green, aboiut 6-12″ long, with many leaflets at about 1-2″. The leaflets fold up at night and droop, making people believe the tree is conserving water, but that is a non-issue at night, so other guesses must be made.

Black Locust Bark

Black Locust Bark

 The bark is a light grey, but unmistakably furrowed and rough. The blooms are white, and hang in clusters 4-8″ long  from the branches. The scent needs to be experienced, but is spectacular.

Black Locust Flowers

Black Locust Flowers

Gardeners would recognize the bloom as similar to peas, and indeed they are in the same family. Black Locust has the ability to fix nitrogen, like all legumes, so the tree is often listed in the saddest of all plant use lists, Mine Reclamation. Micheal Dirr calls it an “Alley Cat Tree”, more as an indication of hardiness and usefulness than anything else. It is a common tree in China, and is called “yanghuai”, or Foreign Scholar Tree, as it does mimic the Scholar Tree native there.

There are many Black Locust trees on campus aside from Stewart Woods. Off the top of my head, I can think of Nichols House, below the ledge at Gifford, McKinley House, and next to Hillcrest Road. The oldest and largest are probably at the McKinley House.

P.S.- A public apology. While running a garden center and growing trees in pots, I became enamoured of a cultivar of Black Locust called “Purple Robe”.  This was a beautiful tree. Nice round shape with good branching, not like a normal locust, crisp lime green leaves, and spectacular purple flowers instead of white. We grew and sold many of them, and it was easy, for they grew fast and looked good in a pot. I even planted one in my back yard, and it would slow traffic down on our road in flower.

Purple Robe Locust Flowers

Purple Robe Locust Flowers

After several years, the trees started falling apart, literally. Some would get a couple of locust borer holes, and snap in half at a gust of wind. Others would branch poorly, and split down the middle. Still more woiuld get riddled with borer holes so bad as to just up and die. Mine did all three.

I only mention all of this because I still run into former customers in town that will not talk to me, or even nod a hello, mad at me for making them fall in love with a fast growing shade tree that died a premature death. It’s terrible to see a tree die in the prime of its life, and believe me, had I known, I wouldn’t have grown or sold them. Sometimes a plant that does well in one part of the country does poorly elsewhere, but that’s not really an excuse, is it?

Teaching with Technology Fair

Categories: Random Thoughts

It’s Commencement (literally, it’s about 9:30 Sunday morning, we’ve been at it since 5 Am, but now us landscapers are hiding around campus working where you can’t see us), hence the lack of any posts the last week or so. I’ve got a lot to write, but being a landscaper in spring has it’s disadvantages, time management being a one of them.  I just wanted to mention I’ll be at the Teaching with Technology Fair on Wednesday, in the Great Hall at Bicentennial Hall from 10-12, showing off the Campus Tree Map. If you’re curious as to the ArcGIS underpinnings of the map, or just want to drop by to talk plants, come on over.

More Vandalism

Categories: Trees

Scene of the crime

Scene of the crime

I read with interest the recent article in the Middlebury Campus on the increase in vandalism this year, as I completely agree. We’ve recently lost another tree to senseless idiocy, this one a rare Silverbell. We’d only planted this tree about a year and a half ago, and it was ripped up out of the ground about 2 weeks before it was due to flower. I could see the little flower buds shriveling up and dying right before my eyes. Not only was this tree ripped up out of the ground, but it was snapped in half at the base as well, I guess in case the first injustice wasn’t enough. This was outside of Allen Hall.

Close up of root system

Close up of root system

That same weekend, someone felt the need to do a little pruning on a paper birch outside of Battell.

The branch as found outside Battell

The branch as found outside Battell The tree

Maybe what concerns me the most is the possibility that, because most of the plant vandalism seems to be taking place outside of freshman dorms, we may be in for 3 more years of this. Once again, any ideas are welcome on how to fix this as a community.