Easter Blooms

Drove through campus this afternoon on my way grocery shopping, and couldn’t help but take some pictures of a couple of things in bloom. It’s 70 degrees as I write, low 80’s yesterday, so that certainly sped some flower buds up I thought were going to hold on for while.

Star Magnolia-Carr Hall
Star Magnolia-Carr Hall

This is a Star Magnolia, Magnolia stellata, in between Forest and Carr Hall on Route 125. Like many of the other magnolias on campus, this one is planted right on top of one of the steam lines that run from the service building to the rest of campus. It’s easy to see the steam lines, they melt snow all winter, and the grass is the first to green in the spring. Someone believed that the heat from the lines would protect what they thought was a marginally hardy plant from the harsh Vermont winters. Perfectly hardy, now the magnolias are in the way for construction. One was moved a couple of years ago from the Axinn Center up to near the tire sculpture near Hillcrest. It’s doing fine, although thinner than the others. The best Star Magnolia is out in the main quad, right behind Voter Hall, but the blooms on that one weren’t quite as open.

Star Magnolias are native to Japan. Other magnolias mimic their distribution like many conifers-some are native in southeast Asia, others native in the southeastern US and central America. Fossil Magnolias (one of the first angiosperms in the flowering fossil record) have been recorded in Europe and Greenland, suggesting that that they were widespread until the continents drifted apart, dying out in the middle of their range.

Corneliancherry Dogwood
Corneliancherry Dogwood

I’m cheating here-this is a picture from my house, although there is some near the Garden of the Seasons. Great yellow flowers right now, a week or so ahead of the forsythia (except for the one below). Large red fruit in the fall, edible but nasty sour. Very lustrous rich green leaves, nice and clean all season with no leaf spot. Not the first shrub I planted at my house, but I am glad I have one.

Crocus at Forest
Crocus at Forest
Crocus in Lawn
Crocus in Lawn

Some Crocus in random locations.

This is Vermont Sun Forsythia- Forsythia mandschurica ‘Vermont Sun’. I wrote about this last year, and it was in bloom April 13. I took this picture on Friday while getting into my car to go home, so that makes it 11 days earlier this year than last.

A watched Spring never boils

The problem with watching the weather is the frustration. Even my years of experience in spring anticipation somehow still hasn’t prepared me for the wait, the fits and starts of the season. The landscape waits patiently, though, and the plants are right where they need to be.

Today in blooms? Well, it’s pretty mellow. The family Betulaceae is showing it’s stuff. On campus, that would the Birch, Hornbeam, and Hop Hornbeam trees, and in shrubs the Corylus, or Hazel, genus. Michael Dirr states, of birch flowers specifically, “the birches flower in April before or with the emerging leaves; they possess a hidden beauty which is lost to most people because they have never examined or considered the birches a flowering species…” After three days of a cold rain, I’ll consider any flower.

Look for large catkins hanging from birches. They hang in clusters of three from the ends of the branches, and have been there unobserved all winter. In Birch they are male and female-in Hazel, the female flowers arise from the leaf buds.

How would I describe the flowering catkins? Ask the Dutch. Catkin comes from the dutch word katje, meaning kitten, as the flowers resemble a kitten’s tail. I’d say I’ll get around to a picture but, well, the buds are swelling on the forsythia, and I swear I saw a couple of whitish blooms on a Magnolia in front of Forest, so I probably will once again ignore the catkins. Hidden beauty is all well and good until the Magnolias start popping.

Campus Tree Map updated

I’ve posted a new export of the campus tree map Google Earth file, on the Campus Tree map page. I’ve added quite a few more campus trees to it, and the official count now stands at 2279. There are a couple of more locations I would like to map, and quite a few more pictures I’d like to find the time to take. This iteration, though, is pretty close to complete.

I risked the potato chips in the keyboard, brushed off my math skills, and starting looking at our tree population in Excel over lunch(es). I’m no spreadsheet guru, but the information I pulled out is interesting, and tells me we’re pointed in the right direction in our urban forest here.

I’m sure I’ve written about this before…An urban forest population such as ours should have no more than 30% of the population from one family, 20% from one genus, and 10% from one species. Some sources say 15-10-5%, but that’s hard this far north. (Brief refresher- Roseaceae is an example of a family, and includes many types of plants, from roses, to crabapples, to Shadblow, etc. A genus is one type of tree, like Maple. A species is a specific type of tree, like Sugar Maple.)  The reasons for a diverse population make sense-let’s look at an example. Emerald Ash Borer  (pdf) is on it’s way to Vermont, as quickly as  a couple of years. Most recently is has been found 30 miles north of the border in Carigan, Quebec.  It attacks the Ash genus, consisting of both Green and White Ash here on campus, and they make up 8.7% of our population, and 8.3% of our canopy cover. Losing our Ash on campus would make a big dent in our population, but imagine if Ash made up greater than 20% of the population, as it has in some urban street tree populations elsewhere.

Our potential problems lie in the Aceraceae family, or maples. We’re ok on the family level, with 22.7% of our trees in the Maple family. The maple family only consists of one genus, Acer, making the genus population a worrisome 22.7% as well. Sugar Maple as a species makes up 12.3% of our trees, and 15.2% of our tree canopy cover (shade), so that is a possible weak link in our forest, should some insect or disease come along to target specifically Sugar maples.

Other statistics aren’t cause for alarm, but are worth noting. The Pinaceae family, Spruce, Pine, and Fir, make up 22.6% of the population, White Pine alone clocking in at 6.6%. Crabapples are 9.3%, close to the 10% species limit.  Slightly more than half, (54.2%) of our tree canopy cover on campus is made up of only 10 species of trees-Norway, Red an d Sugar Maples, Paper Birch, White and Green Ash, Crabapples, Norway Spruce, and White and Austrian Pine.

Another set of data gleaned is the age of the forest. I’m an advocate of planting trees every year, to keep a mixed age population. I measure this not from true age (can’t really know that without cutting trees down), but simply by looking at trunk size, a measurement called Diameter at Breast Height. Young trees, less than 6″ in diameter, are 31% of the population, 6-12″ teenagers are 33%, 12-18″ trees make up 21%, 18-24″ at only 7.6%, and the grand trees larger than 24″ are 7.5% of our population. (There are 34 36″ + trees on campus, 1.5% of the population. I’m thinking of naming them individually) This seems to be a good mixed age population-we wouldn’t want all the trees reaching old age at the same time.

So in all, a good mixed age population, and fairly good species diveristy. Im still open to planting Sugar Maples even, though I’ve been leaning towards oaks in the last couple of years. And I’m always looking for trees we don’t have. This year’s new tree species is  Amur Maackia, I’ve already got one tagged for us at a local nursery. I’m open to locations…

Wind Damage

I’m happy to say that Middlebury didn’t suffer much for tree damage from the storm I wrote about last week. Peak wind gust was only 34 MPH, but power was still out on campus for the better part of the morning. From what I understand a tree fell on a line near a substation. I’ll bet it was nice to have a half of a snow day-bet you thought you out-grew those once you graduated high school. It was nice to see the students making a productive use of their time. And yes, the guys in our landscape department feel bad when we have to plow some of them over. Like real estate, people, it’s all about location, location, location. Think before you sculpt, please.

We lost some branches here and there, notably in some White Pines near Hadley House and Perkins. Some large dead wood also fell out of Sugar Maples near Warner and Starr. Our vigorous pruning of trees on campus prevented a lot more damage, though, as most wood that falls out of trees is dead wood, and we remove much of that before it falls. Two trees did break some live wood, and I feel badly for them.

One is a rare (for this zone) Lacebark Elm in the front quad. You can see the broken tree as you drive south on Route 30.

Lacebark Elm
Lacebark Elm

This is a special little tree, and fortunately the break, while large, probably won’t permanently disfigure the tree. The damage was primarily one large scaffold branch breaking away from the main trunk, and was not surprising. This union between branch and trunk was a weak one, characterized by included bark growing between the two. As the bark on both stem and trunk expand through the years, it pushes against each other, causing the separation to widen. As you can see in the trunk close-up, the dark colored wood was always exposed to outside air-it is the light colored wood that was the sole attachment, and that is where it broke.

Closeup of damage
Closeup of damage

Proper pruning when this tree was young would have prevented this from occurring. Unions like this are easy to spot, and when removed young cause no permanent damage to the tree.

The other significant damage that occurred was more surprising, and also more sad. The wonderful Russian Olive tree just north of the new McCullough plaza lost a couple large branches on the right side, and will be much more noticeable when removed, disfiguring an admittedly funny tree-possibly the state’s largest.

Russian Olive
Russian Olive

This small tree is more often a large shrub-making this specimen quite old. The damage on the left side was from excessive end weight. As the snow collected on the tips of the branches the main stem could no longer hold it, and it broke. The species is not known for very strong wood; being a shrub at heart that is not very surprising.

Damage on the Russian Olive
Damage on the Russian Olive

We’ll prune away the damaged branches as best we can, and attempt some pruning on the other side to balance the rest of the tree out. I’ve been asked about replanting more of this species, but the plant is considered an invasive species, and is currently on the watch list by the Vermont Invasive Exotic Plant Committee.  It’s wonderfully fragrant creamy yellow blossoms in June and July are followed by fruit widely spread by birds, replacing native plants. While birds do love this plant, better bird species richness is found in native plant stands. There are plenty of other fragrant trees and shrubs to pick from in June and July, but I do like the silvery leaves of this one.

Plants of a (mis)Spent Youth

Friends ask me how I got into this line of work. How do can I explain it to a non-plant person? It’s all about the plants, after all, but how? What is it about the flowers, or the mulch, or the dirt? How did I get from playing Led Zeppelin on my eight track, painting my parent’s house white (again) to landscaping? Continue reading Plants of a (mis)Spent Youth

Main Quad Tree Removal

While we dislike removing trees, sometimes we must. The Landscape Department is overseeing the removal of some hazardous trees in the main quad over winter recess. (We like removing trees over recesses–there is no pedestrian traffic and hopefully the ground will be frozen enough so we don’t make much of a mess.)  Since the trees are in a very prominent location, we’ve been consulting with the President’s Staff, as well as the Master Plan Committee, and all are in agreement about the removals. When finished, the look and feel of the main quad will be very different, yet much improved. And, in a bit of synergy, the work aligns with Campus Master Plan. Continue reading Main Quad Tree Removal

Tree Karma

I’m a big believer in tree karma. After all, I spend much of the winter at high altitude pruning trees in the canopy. (Don’t tell my mom-she still worries about running with scissors, so she wouldn’t be so into climbing with chainsaws). So do the trees still like me? I like to think I plant more than remove, but what’s the ratio here at Middlebury?

Trees in an urban forest such as ours are under more stress than in a natural forest environment. Granted, they adapt well, growing wide, as they don’t have their brethren next to them breaking wind (wait, that doesn’t sound right). They rely on each other for support, protection, and for all we know, companionship. Trees on campus get walked upon, climbed, swung from, and occasionally cut into with an axe. Root systems are walked on, soil compressed, all sorts of little indignities befall a campus tree.

Most fight valiantly, but, sadly, some succumb. It’s our job to remove the victims before they fall on something like a building, or, more importantly, someone. In arboriculture, a hazardous tree is defined as a tree that can fall on a target. That means if a tree falls in the woods, it doesn’t make any noise, because there is no target. Many trees on campus have targets-students seem to walk everywhere. So we worry. And cut the occasional tree.

Middlebury College has a vigorous tree planting program. It’s necessary in an urban forest to be continually replacing trees, much like succession in the woods. It should be on-going, as a mixed age population is more sustainable. We aim for diversity as well. No more than 30% of the trees in an urban forest population should come from the same plant family, no more than 20% from the same genus, and no more than 10% from the same species. We’ve been planting trees all along, but also removing some. So, we wondered, what was the karma factor here, were we planting more than removing?

I spent my lunch break looking at pictures of removals, and going through my planting files, worried about our department’s karma. Happily, we’re good, and by quite a bit. I’m in my fourth year here, three growing seasons, and in that time our department has removed 37 trees from the main campus. This does not include 5 or so lost to student damage, and a couple “weed” trees growing out of woodlines. We have planted over 128 trees, for a ratio of better than 3.5 to 1.