Good Replacement for Dying Hemlock?

[crcurrie]

M.D., our climate sure has been moist this year -- about 53" of rain so far! But we had a four year drought just previous, and the odd thing is that the photo showing all the green stuff was taken last year, near the end of the long drought, and the tree this year seems to have lost most of that in spite of the rain. Maybe even the algae is dying!

Would you say I should give it another year, or is it best to cut my losses (no pun intended) and give its replacement a head start (once any soil issues are addressed, of course ...)?

I've even thought about planting a baldcypress a few feet away and hedging my bets (I could transplant the small tree somewhere else if the hemlock recovered). But I suspect that digging a planting hole so close to the sick hemlock might injure it further, and growing in the shadow and rootzone of a larger tree wouldn't exactly be great for the young tree, either.

Chris

 

[Guy Meilleur]

Is that English ivy in that bed with the hemlock? Ivy's very competitive for nutrients and water, and having it near the trunk is no good. Trench certainly a factor; most are ~2' down, to avoid freezing, so that would have whacked a big % of roots.

Nice-looking turf--are pre-emergent herbicides used?

Crown sparse, but no serious dieback noted.

Killing the ivy and building up the soil sounds like a plan. You say there are mature healthy hemlocks nearby--can you harvest some soil and roots from them? The micobes attached to the roots are the best soilbuilder you can find.

I pack it into aeration holes, like mm showed in his airspade photos a while back. I like to use a pick and get it deeper too.

 

[crcurrie]

Thanks for add'l comments, Guy.

To answer your questions, that isn't English Ivy -- it's some other ground cover that I've never seen anywhere else and I can't recall its name. It's not nearly as dense as English ivy, though, and I notice that it's become very sparse around the hemlock this year for some reason -- though not the Japanese maple, where it's still reasonably thick.

The turf has not been treated at all this year -- no herbicides or fertilizers whatsoever. I did hand aerate it this spring and we've had a lot of rain, so it's done better with no treatment this year than it ever did before when I actually put stuff on it.

The dieback on the tree has been from the lower branches up. There was even some of that starting when we moved in six years ago, although it accelerated greatly in the past few years. Most of the lower branches have no needles at all anymore.

I'd never heard the idea of transferring microbes from other trees. I can see what I can do there, although the other hemlocks are all in people's yards and I'm not sure how receptive they'd be to my digging up their lawns and removing soil and roots ...

Chris

 

[Kneejerk Bombas]

With root damage I would expect to see more top down die back. this tree is looking equally sparse from top to bottom.
I am at a disadvatage, not being familiar with the tree or climate, but I'd be looking at insect, fungus, and planting depth.

Could you pull the ground cover back and get a picture of where the trunk goes into the ground?

 

[Sylvatica]

Chris,

A few observations, and I am putting on my hat as a certified designer now.

Beautiful house.

If you don't need shade or screening, skip the big tree idea entirely.

That hemlock will never be up to the standards of your home. Bad crotch (or multiple stems too tight) too. Get rid of it for aesthetics alone.

Think small magnolia (star, sweetbay), sourwood, redbud. Though deciduous, enough structural contrast w/ Jap maple

If must be needled evergreen, maybe hinoki falsecypress or a sciadopitys. I think a high-trained weeping Norway spruce would be magnificent and still be in keeping w/ Victorian theme!

Bringing the scale down in that location would reduce visual competition w/ that gem of a house.

 

[M.D. Vaden]

I've never seen anyone pull a hemlock back to health from what you have there.

If that were my tree, I'd only try to save it if the ends of most all outer twigs were flexible, with live tissue under the bark, and buds that still were alive on the ends.

If so, I'd only give it till next growing season max.

That after aerating the root zone and eliminating any possible problem that may be identifiable.

But if there are plenty of dead brittle twigs and limbs on the outer part of the canopy, I'd play the tree a final melody.

 

[Kneejerk Bombas]

Originally posted by M.D. Vaden
If that were my tree, I'd only try to save it if the ends of most all outer twigs were flexible, with live tissue under the bark, and buds that still were alive on the ends.

But if there are plenty of dead brittle twigs and limbs on the outer part of the canopy, I'd play the tree a final melody.

I think you are getting at the same thing I was, it doesn't look so much like die back as a foliage thing. Foliage issuses are usually simple to work through.

In addition to a picture of the trunk at the base, how about a close up of some foliage or branch tip, one that shows both healthy and diseased parts.

The pictures are tricky. In Hemlock 5, the tree looks like it has a chance, in Hemlock 6 it looks like standing firewood.

 

[Guy Meilleur]

I agree totally w md and mike so I will bow out of this.
Note--Reduction pruning does not look like an option here

 

[crcurrie]

Thanks for all the replies, folks! It seems there is an emerging consensus that this tree is not worth spending any more time and money on. I was particularly intrigued by Silvatica's comments about whether it is even the right tree for the site to begin with. I'm going to discuss with my wife some of the options that Silvatica presented and I suspect we'll probably go with one of those. In particular, I have been converted from the point of view that I want a giant tree there (like a baldcypress). I like big trees but probably other locations on the property would be more optimal -- like the site that may become available from the sinkhole-damaged silver maple ...

What remains, I guess, is to figure out what the soil problems might be under the hemlock and remedy those before planting anything in its place.

Thanks again, everyone! Arborists rule!!!

Chris

 

[Dan F]

Chris,
Sounds like you've made a decision. Good luck with whatever you decide to do.

Some other options that Sylvatica didn't mention are a flowering dogwood, mimosa (not sure if they are hardy there though) and a seven-son-star (if you can keep it pruned, also, I'm not sure if that's what it's called, I can check).

Now about that sinkhole.... Has there been any construction in that corner of the yard in the last year? That's a MUCH too large of a hole to have been caused by an irrigation system installation. At least with which I am familiar with.... Any city water lines there? I think I might be worried about it if there were city lines there. One could have started to leak and cause that......... Could there be an old (abandoned) septic tank there? I could see the lid finally collapsing or shifting, causing the tank to fill in.... Anybody got other ideas?

And, Guy, most sprinkler systems around here are put in within a foot of the surface. The main lines are usually the deepest, the laterals are usually 6-8" below surface. Freezing weather hits, the entire system is blown out and shut down.

And did anyone else see the conk on the trunk of the hemlock? What could have caused that?

Chris- could you get a close up picture of the ground cover? I couldn't get a good ID from the pictures that had it in it. I'm thinking it could be English Ivy, in it's mature form. The mature form looks completely different than the juvenile state....


Dan

 

[Stephen Wiley]

Dan F.,

I do not see a 'conk' fruiting body of fungal pathogen or saprophyte.

I do see a large 'canker' most likely caused by bark fungi or introduced through ovipositor of wood borer or tree crickets.

Due to grade changes in this area and age of the home, I also would suspect a septic system failure for the sink hole.

 

[crcurrie]

I was half expecting someone to mention that large canker on the hemlock trunk before and now someone did! Whatever it is, I'm sure it's quite old -- it hasn't changed in the six years we've been here. I would rather that the canker have caused the demise of the tree rather than soil conditions, of course, since the canker wouldn't be an issue for the new tree.

The sinkhole is actually in back of an old storm drain. There is a street inlet on the road side, but there are two inlets in back, as well. One is about 10-12 feet down and it drains the low spot in our side yard. The other might be as much as 20 feet below grade and that carries a stream that was piped underground during the '50s during the polio scares. The storm drain exterior is a very old brick wall -- likely deteriorating in various places. The inlets also might have leaks in the joints. What likely happened is that ground water coming from overflow from the curb next door was seeping into the drain from the back and carrying soil with it. That produced the large cavity that eventually collapsed. The County is coming sometime in the next several days to look at it; I should know for sure then. I'm hoping they tell me that the problem is with the stream inlet, and that it is too far down to fix w/o huge expense. Then I'll suggest they resurface the stream, which has been a fantasy of mine ever since I moved here! My immediate concern is that I might lose the silver maple tree, though ...

Dan, thanks for the add'l tree suggestions. We have been leaning toward the sweetbay magnolia since it is a native tree and semi-evergreen. Hadn't thought of mimosa. I probably pull up two or three volunteer mimosas every year in my flower beds. But, you know, that tree might just fill the bill, too! Thanks again.

Chris