Canadian Hemlock aka Eastern Hemlock, Tsuga canadensis as Bonsai
This is the first tree I ever collected, over eight years ago now. The development of this tree has been one step forward, two steps back. There is limited information out there on T. canadensis and I’ve only seen two that could be called bonsai (this tree isn’t one of them). This is probably for two reasons: 1) it is hard to find worthy material, and 2) they are a quirky species to work with.
Eastern Hemlock are unique for a number of reasons:
- They very, very much prefer a rich and moist organic growing medium. I almost killed mine by transplanting it into a coarse, inorganic medium. Replacing it with topsoil restored the health of the tree.
- They can tolerate practically any light condition from full shade to full sun. For bonsai development, several hours of direct morning sun is good for promoting backbudding and branch development. Full direct sun tends to cause the foliage to lose it’s rich green colour.
- Despite their delicate and almost “weak” appearance, they heal over wounds better than any conifer I can think of and better than many deciduous trees. This makes grafting easy on T. canadensis.
- The branches are very flexible however they are extremely weak at the crotches. They will suddenly and heart-breakingly tear from the trunk with little notice during heavy (or even moderate) bending operations. However, their capacity to rapidly callus over wounds means that a branch will more often than not survive, even if you have torn half of the base away from the trunk.
I have learned and re-learned these points “the hard way” on this poor specimen over the years. The resulting setbacks have probably doubled the time it should have taken me to get to the current stage of development. Now this tree has immense sentimental value to me despite being one of the last trees that draws the attention of any visitors to my yard.
I believe Eastern Hemlock is by far the most delicate and feminine species native to eastern North America, and perhaps even all of North America. This makes it priceless in our catalogue of native species and worthy of greater attention. I just wish material was easier to come across!

My T. canadensis today after finally getting the main structure set into place after eight long years. Still a long way to go but I think the hard work is done.

Last summer I was trying to fully style the tree and had to stop at this point after I tore a major limb that supported two major branches – the first branch on the left, and the back branch.

The tear in the limb during last summer’s work. Remarkably, the more important branch (second primary branch) survived despite losing much of the secondary growth. The back branch completely died
- Collected and potted up showing the current front.
An Eastern Hemlock Story and a Lesson Learned
Eastern Hemlock (Tsuga canadensis) is rarely seen as bonsai because good material is hard to find. They bark up slowly, and grow in shady protected environments where exciting stunted material is rarely found. I’ve only seen two really good pieces of Eastern Hemlock yamadori that impressed me. One is dead now, and I have been trying (unsuccessfully) to buy the other one for awhile. I’ve never seen a mature and refined T. canadensis bonsai.
This Tsuga was one of the first decent trees I collected, back in 2007. It was growing in a dark understory near a trail were it was getting battered and bruised by passing vehicles. It has the beginnings of mature bark which is a sign of some age. Ring counts on a cut branch lead me to think the tree is 40-50 years old.
It had a shallow root system growing in mostly leaf mold, and I took home a mostly intact rootball. It grew happily in the moldy compost for 3 years, sending out 3 extensions every season. The tree seemed very strong.
Then, I had the bright idea to try and get it in a training pot and some coarse bonsai soil. The tree HATED it. Its growth slowed down, and the apex started to die back. It almost looked like a fungal attack, but whatever it was I am convinced that it was a symptom of a more fundamental problem – the soil mix.
The lesson here it to grow T. canadensis in a fine, organic mix. It may be the low pH that they like. Many people know this already (see Nick Lenz Bonsai from the Wild 2nd Ed.) but I was stubborn and in a phase where I though “bonsai soil is better for everything”.
So this spring I raked about 80% of the bonsai grit out of the pot (without removing the tree). The root system looked pathetic. I packed in sifted top soil and hopefully this will help the tree to recover. If it doesn’t help, I am about ready to throw in the towel with this one.
As a side notes, T. canadensis heals over wounds incredibly well. For such a delicate conifer, you would not expect it. This makes them suitable for grafting. The first branch on the right near the top of this tree is a successful one-point graft.
- As discovered in Spring 2007. I think a tree fell on it a long time ago, and now it was growing in the compost of the rotting tree.
- Potted up after collecting. It was just thrown in a plastic tray and turface sprinkled in the gaps.
- Some one-point grafts were started the next year.
- It was growing well.
- Here it is Spring 2010 showing its strength before I made the mistake of planting it in coarse inorganic bonsai soil (the stuff I use with all my trees).
- Progress of the graft (1 year after starting it).
- Some bark detail.
- The root system was reduced as little as necessary and it was put in a training pot. The root system looked very strong! The nebari is not bad either for a collected conifer. Mike, if you are reading this – thanks for lending me the pot! You will get it back one day, I promise! :)
- After repotting.
- The tree showed weak growth that spring, and dieback in the apex.
- Detail of dieback.
- Here it is this spring, looking quite pathetic.
- Without removing the tree from the pot, I raked and shook away most of the coarse bonsai soil.
- I replaced it with sifted black earth. Hopefully this will correct what I believe to be a pH issue, and the tree can regain strength.
- Here is the tree the other day. It seems to be growing well after its soil enrichment, but I will need more time to know if this solved the problem for sure. As a side note, the spring growth of hemlock is incredibly beautiful. Like yew or spruce, I find the spring growth of these trees just as nice as flowers.