Saving my Weeping Hemlock

[cishepard]

Back in 2015 or so, before I got into keeping bonsai, I bought a nursery Weeping Hemlock to put into this Victorian style iron planter just for something to look good on the patio. It went into potting soil and has been living - even flourishing - in there all this time without a single repot in 10 years!
This is the tree in 2018:


I guess it sort of became a bonsai by default. I started to trim it using bonsai techniques for hemlocks and it was always just there, looking good as I progressed in the hobby. I knew I should have repotted it and put it into a more suitable container (that planter is a horrible shape for anything other than a flowerpot!), but I’ve been afraid to attempt it and was leaving well enough alone …

The tree in 2022:



It looked even better by early 2024, lush and almost trailing the ground, but I don’t have any further photos. However, recently, at some point that I didn’t notice, it started losing it’s needles and looking very poorly coming out of winter this year and I feared it was gone. I don’t know what happened - too hot last summer (it gets full sun afternoon and evening)? Not enough water in winter? Extensive root rot due to a decade in organic soil and a poorly draining pot?

I have been recently gifted a truckload (literally!) of bonsai from a friend who is retiring to a condo, including several large and old hemlocks and I was panicking about my abilities to care for them, so I arranged a private consultation with Frank Corrigan ( @River's Edge ) to assess both my old and new trees, my bonsai methods and address my problem areas. For this tree he recommended a repot now, as it seems like it needs a last resort.

Since all of the new gifted trees are due for repots, and some are huge, I purchased this hoist for lifting the weeping hemlock plus future repotting use:



I had to cut the rootball into more of a straight sided rectangle to get it out of the planter. The hoist worked great. The legs come in 3 sections, and I only used two to get the height I needed, which makes it weigh less and be easier to carry around.





The roots were quite a solid mass on top and did not look too bad - a bit of a rotted hollow in the middle underneath. I did a half bare root (longways) and left the other half intact with the old soil.



I put the tree in a grow box with mesh screen on the bottom and a coarse mix of pumice, lava, granite grit - sifted! (Frank urged me to start sifting my soil properly!) Since the box is wider than the rootball, all sides are backfilled with bonsai mix. Frank explained how to water a 1/2 barerooted tree - the well draining side frequently, the old soil side- only when needed, as best as you can.




The tree has many bare branches, but there are some with new budding. I think >hope< the tree will live, but whether or not it has lost too much to ever look good again (since they don’t backbud), I don’t know.



To whoever has read this far, I do have some questions and would love to hear your opinions;

- Should I move the hemlock to a shadier spot, and for how long (maybe even forever)?
- If and when should I fertilize this year?
- should I start trimming off dead or dead looking/branches without buds now?
- any other advice to save her?

Sorry if I sound like I need hand holding on this tree - besides this one I’ve had a few Mt. Hemlock yamadori, some were old and very nice, collected by Anton Nijhuis, and all have perished under my “care”. And now I have the new, gifted trees - I am determined to keep them alive and thriving!

 

[Bonsai Nut]

That game hoist is a great idea! I could see numerous scenarios where that would come in handy!

I'm going to share with you what my experience has been with Eastern hemlock - weeping and non - and expect that it is probably similar to Western hemlock, though take everything with a grain of salt. I have six large hemlocks in my landscape that have been there about 50 years or so, and have scattered seedlings popping up in wooded areas of my property. I am at the extreme low southern end of their native range, and have been surprised that they are doing relatively well here. The large trees are all planted in full sunshine, though the seedlings are in heavy shade, and I personally think the trees growing in the shade look healthier / fuller. (Side note - I think the trees may have originally been planted in shade, but the larger pines surrounding them have come down over the years). Just last weekend, my daughter picked up a weeping cultivar that she is going to work on, and we plan on keeping it with the Japanese maples in morning sun / full afternoon shade.

I usually start fertilizing a transplanted tree as soon as I see new growth. Since your tree is showing signs it is recovering from stress, I would fertilize now - but would recommend using a dilute liquid fertilizer like Miracle Grow (at half strength). With that concentration, you should see an immediate response, and the strength is low enough you won't risk harming the new roots.

I wouldn't trim anything until after the tree has pushed its spring growth next year. There is a chance that it may push new growth along some of the branches where there is die-back. By next spring the dead branches will become very obvious. They will be completely bare of any needles and brittle to the touch and will snap easily - versus live branches being very flexible.

I think the soil mix is going to make a huge difference. The tree is already responding very favorably. Just give it some time and I think it should come back strongly.

Seedling in total shade:

 

[cishepard]

Thank you for your insight @Bonsai Nut.
I will leave the branches alone and start on a dilute Miracle grow regime.
I’m nervous about how hot the afternoon sun gets here in the PacNW, so I will try to arrange a place for her to get some morning sun and afternoon shade - I might have to rig up a shade sail or something, as there are not many choices in my small backyard!

 

[Bonsai Nut]

Thank you for your insight @Bonsai Nut.
I will leave the branches alone and start on a dilute Miracle grow regime.
I’m nervous about how hot the afternoon sun gets here in the PacNW, so I will try to arrange a place for her to get some morning sun and afternoon shade - I might have to rig up a shade sail or something, as there are not many choices in my small backyard!

Humidity is also a consideration. You tend to have cooler, humid air, which will be less stressful. We have the humidity, but our average high temps in July and August are around 90F.

 

[penumbra]

That game hoist is a great idea! I could see numerous scenarios where that would come in handy!

I'm going to share with you what my experience has been with Eastern hemlock - weeping and non - and expect that it is probably similar to Western hemlock, though take everything with a grain of salt. I have six large hemlocks in my landscape that have been there about 50 years or so, and have scattered seedlings popping up in wooded areas of my property. I am at the extreme low southern end of their native range, and have been surprised that they are doing relatively well here. The large trees are all planted in full sunshine, though the seedlings are in heavy shade, and I personally think the trees growing in the shade look healthier / fuller. (Side note - I think the trees may have originally been planted in shade, but the larger pines surrounding them have come down over the years). Just last weekend, my daughter picked up a weeping cultivar that she is going to work on, and we plan on keeping it with the Japanese maples in morning sun / full afternoon shade.

I usually start fertilizing a transplanted tree as soon as I see new growth. Since your tree is showing signs it is recovering from stress, I would fertilize now - but would recommend using a dilute liquid fertilizer like Miracle Grow (at half strength). With that concentration, you should see an immediate response, and the strength is low enough you won't risk harming the new roots.

I wouldn't trim anything until after the tree has pushed its spring growth next year. There is a chance that it may push new growth along some of the branches where there is die-back. By next spring the dead branches will become very obvious. They will be completely bare of any needles and brittle to the touch and will snap easily - versus live branches being very flexible.

I think the soil mix is going to make a huge difference. The tree is already responding very favorably. Just give it some time and I think it should come back strongly.

Seedling in total shade:
View attachment 598976

I can't say from a single picture, but I believe this is Tsuga carolininia, which has been considered for the endangered species act since 2023. This is a more compact form than Tsuga canadensis. The weeping one pictured looks like a Tsuga canadensis 'Sargentii'. The Carolina Hemlock is also more drought tolerant.

 

[stubmle]

I don't have any in bonsai culture, but hemlocks are pretty common even in my area, and they're even more common further north. They're extremely shade-tolerant, though they do well in sun if given enough water. I most commonly see them in cool, moist areas- along mountain streams, in shaded ravines, etc.
Supposedly they do not like having roots disturbed outside of very specific windows in the Spring, though I do not have any experience repotting these myself.

Keep an eye out for pests, the hemlock woolly adelgid especially has become more of a problem in recent years. It's slowly spreading north up the east coast and the Eastern and Carolina hemlocks are very vulnerable to it. It's present all over the west coast already, but usually doesn't bother the native Western hemlocks out there as much.

 

[cishepard]

Keep an eye out for pests, the hemlock woolly adelgid especially has become more of a problem in recent years. It's slowly spreading north up the east coast and the Eastern and Carolina hemlocks are very vulnerable to it. It's present all over the west coast already, but usually doesn't bother the native Western hemlocks out there as much.

Omg, thanks for mentioning that - One of my new gifted hemlocks is infested with woolly adelgid, so I used a systemic insecticide on it, but of course did not think of doing this tree as well … ¯\(°_o)/¯

 

[cishepard]

The weeping one pictured looks like a Tsuga canadensis 'Sargentii'.

Yes, I believe you’re right! Thanks for that info : )

 

[penumbra]

This doesn't entirely relate to the post, but some of you will find this interesting. This is what a Sargent's Hemlock looks like after about 35 years unrestrained in decent soil.

 

[MrFancyPlants]

The big Nut has great advice.. the one point I’ll quibble on is that I found the more Sun the more growth, when I was in Zone 7. Bnut, is probably right for his area if he is at southern end of Tsuga’s range.
I think it will pull through for you now that you are transitioning to good substrate.

 

[stubmle]

This doesn't entirely relate to the post, but some of you will find this interesting. This is what a Sargent's Hemlock looks like after about 35 years unrestrained in decent soil.
View attachment 598985View attachment 598986

I love these trees... my grandfather planted one near his house back in the Sixties or Seventies, it's massive now. I'll try to get a good picture of it next time I'm there.

You might want to move that one before it gets any bigger!

 

[penumbra]

I love these trees... my grandfather planted one near his house back in the Sixties or Seventies, it's massive now. I'll try to get a good picture of it next time I'm there.

You might want to move that one before it gets any bigger!

Thanks, but at my age I am not concerned. I have pruned it a couple of times.