Trenched Eastern Hemlock...

[Blinky]

This is a fairly large, old Tsuga canadensis next to a historic home... right next to it. Recently they had to have water service replaced and a deep trench went right by it. Large roots were severed. I didn't see the trench or the roots, all I have are these pics taken by the property owner. When i asked him to show me how big the severed roots were he made a circle with his hands about 7" or 8" in diameter. I can't see any roots that large in the picture but I don't doubt him, he's a smart, practical guy.

So what do you think? Will it recover and live on? This is an important tree. taking it down would be bad.

 

[oldoakman]

The bigger question here is will the tree stand up? Hemlocks are notoriously shallow rooted and from what I can see in the photos, the root plate has been compromised along two axis. I would say that a brief shower and a moderate wind will topple this baby, so the next question is what are the targets? If neither of the above happens, then chances are better than average that the tree will die. This is why I am a proponent of directional boring.

 

[guymayor]

Too bad they did not reroute that line. Prognosis poor. If desired by owner, emergency measures could include misting the tree. The trenches are now filled, so need to redig to clean up their cuts and replace with bioactive soil. Paclobutrazol and phosphite. need a sub tech up there?

 

[zale]

I agree with the Paclobutrazol and phosphite suggestion. I would not redig the trench though. Instead of installing a misting system in the tree, I would install a temporary drip irrigation system in the critical root zone area of the tree.
If compaction is a issue due to the stockpiling of the soil and the machinery, I would also Air Spade the Critical Root Zone (CRZ) to break up the compaction and incorporate a composted mulch around the CRZ. How much are the clients willing to spend?

If the tree dies, its not your fault. Be honest with the client and let them know its 50/50 at best.

 

[flyingsquirrel25]

Blinky,
Its to bad customers dont call the arborist first. Get us involved early in the planning of something like this. It looks like they might have money and yard anyhow, whats another 40, 50, or even 60 feet of trench? Or air spade? With adelgid, elongate scale and all the other malidies hemlock has/gets I wouldnt hold out much hope. As said prior, if it doesnt fall over first. If they owner wants to keep the tree, I think i would make them sign a liabilty clause or something.

 

[Daniel]

I do wonder how much difference it would be for the tree to make those clean cuts on the large roots, rather than just tearing them up with a backhoe..

To me it makes sense that it is worth the time and energy needed to find and prune the large roots properly, though its just tough to say... who really knows?? how often do we get to see the results of either way? and on what species?? And even when we are watching, what can we really see??? the tree either stands/lives or fails/dies.. we can't see the decay without going to a lot of trouble.. So the empirical experience needed to speak intelligently on the subject seems like it is going to be hard to come by.

Seems like the majority of people are not willing to spend the money to get questionable benefits for their trees. When you prune a tree, the customer can see the results.. When you prune the roots, they have to take your word for it.. and the word is very "iffy"... not sure it it will work or not , but if you have $1-2K to spend, we'll give it a shot.. Seems like that would be hard to sell..

That said, I was thinking of setting up an air spade kit with the idea of marketing the service through utility/sewer installers, that could recommend the service prior to digging for those that were concerned about their trees. Seems like that would be provide a motivated and well qualified set of leads. Have yet to follow through on the idea.. In part just because I lack the experience to sell the work with confidence..

 

[Eric_E]

Chip,

I can't tell from the pictures so I'll ask. Is there open soil under the porch? If so there may be a significant amount of roots under the porch.