I was going to do another tree-related topic first, but in response to Greg’s (?) request for some of today’s photos, I’ll switch. Girdling is anything that cuts off the movement of water and nutrients up from the roots to the lea
ves, or sugars made by the leaves down to the roots, all of which occurs in the outer layers of the tree, just under the bark. So if it’s all the way around it will kill the tree. It it’s part way around it will inhibit the growth.
I saw a couple of trees on Comm Ave. near BC today with these plastic ties, probably something to do with the Marathon. Anyone attaching things to city trees is supposed to get a permit, and anything like this should be removed after the event, because as the tree grows it will basically choke itself. I cut off the ones I saw, but if anyone notices anything like this on a tree, please remove it.
Another thing to look out for and remove is nurs
ery tags. I noticed this almost invisible wire on a tree on Central Ave. in Newtonville. When the tree was planted years ago it would have been loose, but now it’s starting to cut into this branch (which probably shouldn’t have been allowed to get this big, but that’s another story). It’s nice to leave a species label on when a tree is young so people can see what kind it is, but it’s best to have it on a low, non-permanent branch, and definitely not around the trunk.
Another form of girdling is string trimmer or lawnmower damage that cuts through the bark. This pair of photos are, I think, the same tree by the Richardson St. parking lot in Newton Corner. At left is from July 2008, when I watched the three trees there get sideswiped by a rider-mower, apparently not for the first time. It’s on my way to the Y so I started weeding and mulching them so a lawnmower would never ha
ve to get that close again. (The worst damaged tree toppled over a couple of winters ago; the third tree is really struggling.) The right photo is this morning, showing suckers at the base which are a typical tree response to stress or damage. They need to be cut off, over and over again. I hope this tree at least will survive.
@Julie – is bark mulch piled against the base of a tree likewise considered girdling? I had an arborist some years back helping me out with a bid ole sugar maple in my back yard and he told me that the practice of piling bark mulch against the base of a tree is very bad for the tree. This is a practice I see repeated around Newton, particularly as the City dresses up the streets in advance of Marathon Monday. It looks very tidy but it does not promote the health of the tree (according to him).
The tree w the plastic band looks like it has band marks higher up as well. Maybe those mark Marathons past — a BC “Smoot” of sorts
Also, how about those big metal plates that they put around trees in high traffic areas. I love the way they look and protect, but look at the ones in Newton Corner, the tree has pulled up the plates, and now they are dangerous to pedestrians AND the trees. And there are lots of spots that need the plates, so I don’t understand why the city doesn’t do some resorting. (for instance, Newtonville village center has none, and the trees all get compacted and walked on constantly.
Lisap is right about the mulch. Google “mulch volcanos” for all the reasons why it’s bad. Ideally mulch shouldn’t touch the trunk, there should be a gap. But no one seems to want to weed. At least, taper it down to nothing around the trunk, and only mulch 2-4 inches deep further out.
One of the bad consequences of mulch volcanos is that over time the tree may put out roots into the mulch, which may become girdling roots.
Don’t get me started on the tree grates. Most of them probably should have come off 15 years ago when the root flares started getting close to the edge of the openings. Now many of them are girdling the trees at the base. A bunch of us inventoried all the grates last fall in hopes of triaging the ones that need to be removed ASAP. For a lot of the trees it’s probably too late. One of the consequences of not having any forestry workers for two decades. I’ll do another post on grate horror stories.
The grates, which all seem to come from Neenah Foundry, are different sizes, mostly 48″ or 60″ square, and a lot of round ones in Newton Highlands, so they’re not necessarily easily exchangeable. They’re also mostly bolted together from underneath and there’s not enough clearance to tip the grates up to get at the bolts, and they’re so corroded they’d be hard to undo, which leaves trying to saw between the grate halves with a very thin bolt saw.
By far the worst cases of girdling is that which leads to tree death by strangulation. Some of the worst cases I’ve seen are caused by the invasive asian bittersweet vine found commonly around the city. The newly proposed Upper Falls Greenway, for example, has some of the worst cases – take a look Sunday while you help pickup trash…
That is very frustrating on the tree grates. Street trees are hard enough to grow as it is, amazing that the city hasn’t taken care of them. And they are a huge obstacle once they get raised up by the trees.
Julia, do you then not recommend grates at all? I think in high traffic areas they have their purpose if well-maintained.
I’d love for Newtonville to get some new street trees. There are multiple ones that need replacing.
@Julia, I’d love to joint “the bunch of us” who go out and inspect the tree gates etc. I was part of the ’91 Newton tree count, and learned so much. Who should I contact? I’d love to help.
fignewtonville, I agree that if you stay on top of them, grates have some advantages, mainly keeping pedestrian traffic weight off the tree roots. I did become relatively fond of the 48″ grates with 32″ inner openings and no bolts. Why anyone put on grates 48′ grates with only 12″ inner openings and bolted them is beyond me.
But they have some disadvantages, too, like having weeds grow up from between spokes, or a tendency to fill up with trash or alternatively, too much mulch. Marc Welch doesn’t use them, I think mainly because he hasn’t had any tree crew to go disassemble them when it’s time to take them out. If you put them on without bolting them, they’d be a lot easier to remove when you wanted to, but also maybe for scrap metal thieves. And the grates themselves cost money. Not that there’s been any planting to speak of in the village centers, just a few red maples near the Newton Centre T which I think are in raised beds, so no grates needed.
Marie, email [email protected] and ask Katherine to forward it to me. Or if you use twitter message me @JuliaMalakie
This was a great thread because I learned a lot and didn’t have to comment. I will never again place mulch on top of trees and shrubs in our yard. I learned something from every post. I didn”t know the Asian Bittersweet Vine existed, let alone what kind of a problem it is here. Thanks.
Hoss, I just realized what I think you meant about the “band marks”, that old ones might move higher as the tree grows? That’s a funny misconception — actually, trees grow from the ends out, so to speak, so any particular point on the trunk stays the exact same height over time. I think those dark bands are scars where the trunk is growing over past pruning cuts, although usually they’re rounder not elongated. And as I zoom in I think I see a staple (aaack). Don’t staple things to trees either.
Julia — I don’t know if you listen to NPR’s “Car Talk” but trees growing from the top was the solution to one of their puzzlers this month. I should have recalled that!
I love to garden so I enjoy seeing your posts
Julia, Hoss, it’s usually true that trees grow exclusively from their tops, but not always:
http://www.amjbot.org/content/early/2012/03/05/ajb.1100523.abstract
Ah, but if you’d taken Marc’s pruning class, you’d know that palm ‘trees’ are actually grass! ;-) Unless there’s some other variety I don’t know about!