Tree of the Month
Hawthorne • Crataegus sp.

by Gilbert A Smith
ISA Certified Master Arborist

Thirty five years ago this month Lesley, my pretty young bride, stepped out from behind a Hawthorn and right there we were married in the middle of a grove of Downey Hawthorns in full flower. Every year when the Downeys dress up in their creamy, white clusters of daisy like flowers, we remember that happy day. If you were to pin me down I might say that the Downey Hawthorn is my favorite tree.

Here are the other reasons I like it...

Its a tough, thorny, native, prairie tree, one of the few that could stand up to the harsh conditions northern Illinois threw at it, like fires, and still ably compete with the mighty prairie. I love the horizontal branches seeming to defy gravity as they gently arch almost to the ground. The sinewy trunk speaks of graceful aging, as each year  older it looks more lovely. There are specimens that continue to live at the Morton Arboretum that pre-date the Arboretum itself perhaps older than 200 years.  

The birds love them because of the thorny protection from predators and the berries that last into the winter. Native Americans used the fruit, leaves, and roots for heart and circulation problems. So also did the Greeks, and the Chinese as early as the year 659. Currently European physicians prescribe Hawthorn preparations for the treatment of early stages of heart failure.*

Beautiful in the summer as well as the winter, don’t let a few thorns point you away from the Hawthorn.

* Foster, S. Herbs for Your Health, Loveland Colorado: Interweave Press, 1996

Bronze Birch Borer: Who is the bad guy, the Birch Borer, or the Birch Planter?

Backyard Wisdom by Gilbert A Smith
ISA Certified Master Arborist

Birches

Birch tree infested with Bronze Birch Borer exhibiting the classic D-shaped exit holes.When I see Birches bend left to right

Across the lines of straighter darker trees,
I like to think some boy’s been swinging them.
But swinging doesn’t bend them down to stay
As ice storms do.  Often you must have seen them
Loaded with ice a sunny winter morning
After a rain.  They click upon themselves
As the breeze rises, and turn many-colored
As the stir cracks and crazes their enamel
Soon the sun’s warmth makes them shed crystal shells
Shattering and avalanching on the snow-crust-
Such heaps of broken glass to sweep away
You’d think the inner dome of heaven had fallen.
They are dragged to the withered bracken by the load,
And they seem not to break; though once they are bowed
So low for so long, they never right themselves:
You may see their trunks arching in the woods
Years afterwards, trailing their leaves on the ground
Like girls in hands and knees that throw their hair
Before them over their heads to dry in the sun.
But I was going to say when Truth broke in
With all her matter-of-fact about the ice storm
I should prefer to have some boy bend them
As he went out and in to fetch the cows-
Some boy too far from town to learn baseball,
Whose only play was what he found himself,
Summer or winter, and could play alone.
One by one he subdued his father’s trees
By riding them down over and over again
Until he took the stiffness out of them,
And not one but hung limp, not one was left
For him to conquer. He learned all there was
To learn about not launching out too soon
And so not carrying the tree away
Clear to the ground. He always kept his poise
To the top branches, climbing carefully
With the same pains you use to fill a cup
Up to the brim, and even above the brim.
Then he flung outward, feet first, with a swish,
Kicking his way down through the air to the ground.
So was I once myself a swinger of birches
And so I dream of going back to be
It’s when I’m weary of considerations,
And life is too much like a pathless wood
Where your face burns and tickles with the cobwebs
Broken across it and one eye is weeping
From a twig’s having lashed across it open.
I’d like to get away from earth awhile
And then come back to it and begin over.
May no fate willfully misunderstand me
And half grant what I wish and snatch me away
Not to return. Earth’s the right place for love:
I don’t know where it’s likely to go better.
I’d like to go by climbing a birch tree,
And climb black branches up a snow-white trunk
Toward heaven, till the tree could bear no more,
But dipped it’s top and set me down again.
That would be good both going and coming back.
One could do worse than be a swinger of birches.
    - Robert Frost

In Concord Massachusetts around Walden Pond the famous White Birch trees are dying. They are dying in Door County, Wisconsin where they are native and in the Chicago area where they are not native. If you Google it you will learn that the culprit killing our birches is the Bronze Birch Borer and the remedy is to kill the borer. Most people assume that the Birch Borer is an invader with no natural predators like the Emerald Ash Borer and that the only options are to give up on growing our beloved White Birch, or to pour on the pesticides. Don’t worry, there are other options.

So let me tell you a story about White Birches.  They are, like our European ancestors, a pioneer species. They grow on the edges of the forest and they are the first to colonize burnt or logged out areas. A fast growing and relatively fast dying tree, in a sense Birch prepare the way for the slower growing, climax forest. That’s their job. They live about 100 years.

Coincidentally about 140 years ago we stopped using trees as our primary fuel source and so stopped creating massive empty spaces for the Birch to colonize. Today, the lovely stands of White Birch that Robert Frost was familiar with are old,weak and it is time for Maple and Beech to succeed them. Nature efficiently recycles everything and in this case the Bronze Birch Borer is the good agent of change. The female Borer beetle flies around avoiding healthy Birch trees and laying her eggs only on failing birches.  She knows that her eggs will not survive in a healthy Birch so she doesn’t bother. To us, however it appears that the borer is killing the lovely stands of Birch in New England when what we’re seeing is just a normal, natural, healthy life cycle.

Travel 1000 miles west to our Prairie State and you will also observe dying, borer infested, White Birch. In this place the Birch are not weakened by normal aging but by being planted in heavy clay soil. They don’t like it. But we love them, and so we blame the poor Birch borer. Or we plant borer resistant River Birch or hybrid Birch. Neither of these like our alkaline, poorly drained, heavy, clay soil either and...its just not the same as a delicate Paper Bark Birch. I ask you, who is the bad guy, the borer or the one who plants the Birch?  

But we just can’t help ourselves!  We want, like Robert Frost, to imagine being “swingers of birches.” So what do we do? Here’s the secret that surprisingly most of the landscapers don’t know. These are the Morton Arboretum’s recommendations for non-chemical control of Bronze Birch Borer.

1. Plant at least 8” higher than the soil line in a high and dry area.(see our planting abstract)
2. Mulch with peat moss, compost, and wood chips out to the expected branch spread.(see our mulching abstract)
3. No ground covers or grass underneath to stress the Birch. (a few non competitive flowers or shrubs are fine)  
4. Water heavily during drought but no more often than once a week.(see our watering abstract)
5. Enjoy your White Birch while it lasts which may be 50 years and then thank it and let it go.

Lichen, Should We Like it or Not?

Mother Nature's Moment
by Lesley Bruce Smith ISA Certified Arborist

We so often get asked questions about the “green fungus thing” growing on trees, usually with concern that something is wrong with the tree.  This is not just a fungus, but actually a unique composite organism of both fungus and a photosynthetic partner of algae.  The fungus actually surrounds the algal cells and the resulting organism becomes much different than either the fungus or the algae separately.  It is a pioneer “plant like” species called lichen that can grow on rocks, sterile soil, sand and tree bark.  It is an important nitrogen fixer that supplies nutrients to the soil and can grow in very harsh conditions.

There are thousands of species of lichens and they are found in every corner of the globe, both in extreme cold and desert heat. Lichens are sensitive to pollution and as such are a good marker for environmental problems.  If you have lichens, it means your air is less polluted.  It is an important food source for caribou in the far north and we have seen it used in the nests of hummingbirds.

The important thing with regards to trees, is that lichens live in a happy relationship with the trees and are in no way harmful or an indication that anything is wrong with your trees.  We usually see it on the north side of tree trunks or in more shady or moist conditions.  So when it comes to lichens, we can like them.