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Satin Moth

Categories: Midd Blogosphere

I love getting emails from people concerning the landscape. After all, with more than 300 acres, there are probably things happening I’m missing. And in the chaos that is Commencement and Reunion, I was missing a big one.

Professor Jeff Byers wrote last weekend-

I  don’t know if there is anything you can (or would) do anything about, but there is an oak tree between BiHall and Coffrin that was in the process of being totally devoured by gypsy moth caterpillars!  There were so many that I could hear the hum of their munching under that particular tree.

I went right over. (the joys and perils of instant email on my phone-it was a Sunday.) I was terrified it was the giant Pin oak tree, the one that made the list of the twelve oldest trees on campus. Fortunately, it was one of the Poplars nearby. And was I impressed.

I couldn’t hear the munching, I think they were all fat and lazy by the time I got there. Much like me on a sunday. Not Jeff-have you read his blog? The last time I did a trail run up the wrong secret side of Snake Mountain I came down with Strep. I reached up to one of the many defoliated leaves, and grabbed a caterpillar.

 

Bugs don't freak me out, snakes do.

Bugs don’t freak me out, snakes do.

Jeromy Gardner, our elm guru from Bartlett Tree in Manchester, correctly identified it as Satin Moth. Not worrying, but has a habit of building a large population every so often and completly covering a tree, in this case our White Poplar. Here’s a great article, if you are interested. They were originally thought to only attack exotic poplars, such as Lombardy poplar and European White poplar (what ours is), but now also is seen in forest stands, and could become significant if defoliation occurs for several years in a row. It does, however, have plenty of natural enemies, including parasitic insects, bacteria, fungi, even birds.

Satin Moth-moth phase. Photo courtesy Perry Hampson, Bugwood.org

Satin Moth-moth phase.
Photo courtesy Perry Hampson, Bugwood.org

So all that remains on the tree are the major veins of all the leaves, everything in between them eaten. I fully expect the tree to re-leaf in a couple of weeks or so. What is even more interesting is the other white poplar about 30′ away, with only a minimal population. The infested one was in a construction zone a couple of years ago. Maybe the stress of root compaction has something to do with this? Or I’ll be writing about both trees being infested next year…

Skeleton-ized tree.

Skeleton-ized tree.

Thanks to Jeff for pointing it out. Maybe I’ll host a ‘trailrun’ of the trees on campus someday this summer. Better start training now.

Emerald Ash Borer Presentation-This Wednesday

Categories: Midd Blogosphere

Part of my absence from the blog would be teaching my winter term class “Trees and the Urban Forest” again this semester. It’s a great class, in a super rushed sort of way all winter term classes probably are.

As you may well be aware, the Emerald Ash Borer is a small exotic insect invading the country, and is poised to enter Vermont in the next couple of years. It has the potential to eliminate all the native Ash trees from the state. Just on the campus grounds itself we have over 200 large Ash trees that will need to be removed at great expense, and replanted. For a quick explaination, see http://www.vtinvasives.org/invaders/emerald-ash-borer .

Two years ago my winter term class took a draft of an emergency preparedness plan for the eventual arrival of the insect from the State Department of Forests, Parks, and Recreation and completed it for the Town of Middlebury. This winter term we are now drafting the plan for Middlebury College. This includes surveying all the Ash on campus, coming up with options for treatment or removal, giving replanting options, and running a computer model to calculate the lost benefits from these trees, including stormwater and pollution abatement, carbon sequestration, and energy savings.

We’d be honored if you could join us to present the plan to the College community on Wednesday, January 28th at noon, in The Orchard, room 103 in the Franklin Environmental Center. I understand it’s short notice (sorry!) and winter term is crazy in even a relaxing year. Please feel free to email me with questions, and if you know of someone else that would be interested, please let them know!

The Botany of Syrup

Categories: Midd Blogosphere

Any kid will tell you maple syrup is special, but how special? Is tapping a maple tree like putting a spigot in the trunk? And why maple?

In a wonderful book I’ve written about before by Nalini M. Nadkarni called “Between Earth and Sky-Our Intimate Connection to Trees” she writes of how botanists and tree physiologists have been looking at how sap is produced within maple in the last couple of decades. Like many things, the wild world of maple syrup seems like a freak chance, a perfect random combination of physiology.

A tree’s goal, aside from reproduction, is to feed itself-it’s tough being an autotroph, and a whole lot of work. Photosynthesis takes place all summer long, making sugars for respiration, growth, reproduction, and a little extra. This extra, in a sugar maple, gets stored as starches within the sapwood of the tree. The sapwood, as the name sounds, is the area of the trunk and branches where water and sugars move around, located within the first couple rings of the wood.

As my winter term class hopefully remembers, Sugar maple is one of our “live slow, die old” species of trees. These trees are more shade tolerant, in life for the long haul, and have the foresight to save extra sugar for lean times, such as the introduction of shade or competition. Other tree species, such as Poplar, live fast and die young, and burn through all their sugar like a hyper 3 old, just as prone to growth spurts as an Aspen in the spring.

Early spring brings sun, a little higher in the sky, and better able to warm. Cats in our house know this, moving away from the woodstove and into little patches of sunlight on soft surfaces. Trees know this too, as the sun warms the bark and the wood. The air may be below freezing, but tree surfaces and interiors could be well above freezing. Once the wood gets to be above 40 degrees, enzymes turn these stored starches into sugars, mostly sucrose, and the sugar is now within the sap. This explains the magical sugaring temperature of 40, any warmer and this process stops.

The other freak chance miracle of maple is getting the sap flowing out of the tree. Not all trees can do this. Water is moved throughout the xylem of the tree by capillary action and transpiration, meaning the leaves need to be on the tree for water to move very effectively. That  would ordinarily make for tough sugaring in March and April, except in Maple.

In maple trees the space around the wood fibers is filled with gas, not water like most plants. When the temperature drops, this gas contracts, making space for the sap laden with sugar in between the cells. So water can move upwards from the roots by capillary action without the benefit of transpiration from leaves. This water freezes at night between the cells.

The day brings warm temperatures, melting this ice and expanding the gas, forcing water down the branches into the stems and trunks of the tree. The taps put into tree trunks to collect sap pierce the xylem all this sap is moving through, and water flows down the tap into the bucket or plastic line.

Interested biology students should read another blog, The Botanist in the Kitchen, http://botanistinthekitchen.wordpress.com/2013/03/18/maple-syrup-mechanics/ , and a cool roadtrip would be the Proctor Maple Research Facility of my old school UVM.

 

The Butternut Seed Orchard

Categories: Midd Blogosphere

I’ve learned this summer a wonderful way to get attention is to build a one acre, 8′ high deer exclusion fence out on South Street past Eastview, brush hog down the existing corn, and not tell anyone what we are doing.

The landscape department, working with the State of Vermont, the US Forest Service, and a local researcher from UVM (Dale Bergdahl, father in law to local Middlebury College hero Mike Kiernan) applied for and received a grant from the Vermont Department of Forest, Parks and Recreation to erect the fence to grow Butternut trees. Butternut is threatened by Butternut Canker, a fungus with the potential to wipe out all Butternut across the United States. When found, disease resistant trees are grafted and grown for seed. An orchard was already established in Brandon, but another in a different locale (geographical as well as horticultural) is always preferred.

Deer love young butternut trees, hence the fence.

I’ve written a large explanation on the project on the blog here, it’s an entire page-Butternut Seed Orchard. I should give profuse thanks to Barbara Schultz, the forest health program manager in the Vermont Dept. of Forests, Parks and Recreation for an immense amount of work to make it possible,  Chris Casey  of the US Forest Service and Tom Simmons of the Vermont Dept. of FPR. And also, most importantly, local volunteer Sally Thodal for helping plant Butternut trees on one of the hottest days of the year.

Feel free to email any questions you have, and say hi to the trees as you drive by.

Cultivating Hope, Wisdom, Compassion, and a Tree

Categories: Midd Blogosphere

Nature can teach us many things. Life, death, love. And Hope, Wisdom, and Compassion. How appropriate the 14th Dalai Lama uses ‘cultivating’, the act of promoting growth, to describe his wish for the dissemination of his main tenants for the human race to strive for.

Sogyal Rinpoche, the Buddist author of the Tibetan Book of Living and Dying, writes of trees:

Think of a tree. When you think of a tree, you tend to think of a distinctly defined object. But when you look at it more closely, you will see that it has no independent existence. When you contemplate it, you will find that it dissolves into an extremely subtle net of relationships that stretch across the universe. The rain that falls on its leaves, the wind that sways it, the soil that nourishes and sustains it all the seasons form part of the tree. As you think about the tree more and more you will discover that everything in the universe helps make the tree what it is; that it cannot be isolated from anything else and at every moment its nature is subtly changing.

A Bur Oak is planted next to the Garden of the Seasons just south of the main library, waiting to be blessed by His Holiness the Dalai Lama. Think about this tree, as it grows tall and wide, its roots spreading far across the quad joining its companions, and be reminded that like a tree, we all depend upon each other as well: we all share a subtle net of relationships. Let the small oak show our hope, our faith in growth and long life, as our grandchildren will see the large tree. And let it teach us wisdom, like the timeless ‘wise old oak’ of our childhood stories, and learn from it compassion, as no tree stands alone.

Bur Oak by the Garden of the Seasons

Watering

Categories: Midd Blogosphere

Pick up any plant biology book, and they consistently list the three macro nutrients all plants need as N, P, and K, the chemical symbols for Nitrogen, Potassium, and Phosphorus. But really, what we share with plants is a need for ‘macro’ macro nutrients, something so profoundly necessary that the books don’t even feel the need to list them, and they form the backbone of all life. We’re talking about C, H, and O, or Carbon, Hydrogen, and Oxygen.

The carbon and the oxygen are easy, the plants are getting that in the air we breathe. It’s the Hydrogen that’s been stressing me out lately. Plants obtain it solely from water, through photosynthesis. I always remember my snide remarks in the retail garden center world, when a customer would ask me what kind of fertilizer to buy with their new purchases. For the most part, I’d tell them the single greatest thing they could do would be to water.

How much? It’s a good question with no real definitive answer. I remember from who knows where that gardens in the northeast need about 1/2″ of rain a week in the growing season, and an article on strawberry production I found says about the same (actually .63″). Trees need quite a bit more, though, as they have much more extensive roots throughout the soil horizon. Plan on 2″ of rain a week. I found a handy online calculator to do the math, but here’s a quick answer. A newly planted tree with about a 2″ trunk, should have a 5′ x 5′ zone watered around it, so that’s about 30 gallons, pretending to be a 2″ rain.

Sounds a little high, but the wild and woolly world of plants is never easy.  Last year we were averaging 4″ of rain a month, and we didn’t have to do any supplemental watering. On cloudy days plants don’t transpire, or lose water, at as great a clip, so maybe last year it was fine.

Or not. We’re running around like chickens with our heads cut off right now, watering every tree we’ve planted for the last 3 years. (that’s a lot) All of our recently planted trees are showing drought stress, and I’m wondering if I hadn’t watered enough in the last 2 wet years to well establish the trees. When watering, it is best to water a lot all at once, so that the roots have ample moisture and can grow long and deep. Too little water, and the tree keeps its roots near the surface, where the water is, and this makes it less drought resistant in the long run.

Gator Bags for Watering

We water all trees with 40-50 gallons of water about every 2 weeks. We use two gator bags zipped together, and they drain over the course of about a day. We hand water any tree we missed, and then gator bag it. In this heat and drought, I’d like to water weekly, but I’ve been checking the ground around the trees, and I think we’re keeping up.

Another good trick I learned once when hand watering is to watch the ground as it absorbs water from the hose. I think this is the one of the Eliot Coleman gardening books, but I loaned my copy out and now it’s gone. Once the ground starts to get saturated, the top gets glossy. Take the hose off that spot, and the glossiness will disappear. If you can count to 3 before the glossiness is gone, the ground is moist enough.

Drought stress symptoms in Birch

identifying drought stress in plants can be tricky, especially in herbaceous plants like annuals and perennials. Woody plants are easier. The inner leaves of the tree turn yellow and fall off. I find this remarkable. It isn’t like trees have brains, but here they are smart enough to drop the inner, less efficient leaves, to conserve its precious water for the maximally producing outer leaves. By the time your plants are showing symptoms of drought, obviously much damage is done. Plants are pretty hardy, so even with serious problems the tree will probably be fine.

Season Creep

Categories: Midd Blogosphere

Everybody has their own phenologies, their own timing of spring. First day the snow shovels get put away (unused in my driveway at all this year, I might add), first day of working without long johns on, or maybe the first day of wearing shorts. I’ve always dreamed as a horticulturist of keeping a journal, tracking of events throughout the years such as first frost, peepers in the pond, first robin at the feeder. Yesterday I realized I sorta had one, and that I hadn’t posted to it in a while. So here I am…

One of my harbingers of spring is the opening of forsythia. It’s a plant I grew up with in our backyard, and the bright yellow flowers more than anything else speak spring to my weary winter frame. After arriving to work yesterday I saw the ‘Vermont Sun’ Forsythia in bloom next to the service building parking lot. Early. I first wrote about this hedge of Forsythia when in bloom on April 13, 2009, and wrote about it again in 2010 when it way 11 days earlier in bloom, on April 4. For the record, the bloom date this year was yesterday, March 20. Peepers were in my pond Monday the 19th of March, a blog post on them in 2010 was April 2.

Phenology, not brought to you by the letter “F”, comes from the greek phaino, meaning to show or appear. It’s the study of recurring life cycles of what is around us, the timing of insects, plants, mammals, and the relationship of time to weather and climate. There is even a USA National Phenology Network, using volunteers across the nation to study these cycles. A great example is the Cloned Plants Project, a partnership with the aforementioned  USA NPN and the National Weather Service, where clones of either a lilac or flowering dogwood are planted in an observer’s yard and bloom times noted throughout the years.

Obviously, this is wonderful data for global warming. More inputs than air temperature factor into when trees leaf out in the spring. Daylength certainly plays a part, as well as moisture conditions the previous fall, and amount of cold temperatures in the winter. But air temperature is the biggie. A study of oak leaf emergence in England since 1947 has indicated that a 1 degree rise in global temperature is associated with a 7 day earlier tree leafing. This is called Season Creep, and scientists point to this as one of the first effects of global warming that we can actually see in the present, with most of the other detrimental effects taking place in the future.

So where does this put us right now? I’ve been getting many questions on if this early spring will hurt the trees or landscape, and the best answer isn’t cut and dry. The worry is a late frost or freeze after the buds have opened, or shoots emerged from the ground. Short answer? The plants will be fine.Trees losing their first set of leaves can regrow new ones from secondary buds. Like beer on a worknight, it isn’t something to make a habit, but once in a while it isn’t going to hurt anything. And bulbs and perennials emerging from the ground know just when it is safe to come out-a frost never seems to bother them.

The impact of a freeze will be bad for us humans. For example, apples bloom before the leaves emerge, so should they bloom and get pollinated, a late freeze will destroy most of the crop for the year. There are no secondary buds for flowers.

The mild and early spring will cause other problems as well. Those suffering from allergies are miserable all the sooner. And the short, mild winter did nothing to mitigate the deer tick population, so extra care should be taken. If you are interested in tracking the spring and summer phenologically, I can’t speak highly enough of the UMass Landscape Message, posted weekly.