Questions about a large spruce

Hi, I’ve enjoyed reading the posts on this site for a while, and I finally joined. Glad to be here.

I have a couple questions about a large spruce I acquired from our local botanic garden several years ago: one about back-budding, and the other about digging it up to put into a training pot.

  1. A couple years after I bought the tree, I took it to a class, and a knowledgable teacher guided me to chop it and remove several unwanted branches from the very heavy and nicely tapered trunk. The result was a short tree with almost evenly-spaced branches radiating out from the trunk. I waited patiently for a couple years for some back-budding, but didn’t get too much. Then I decided to cut back about a third of the foliage at the extremity of each branch, and I did get some nice back-budding. I’ve done that for the past few years, but the back-budding has slowed. In the meantime, the tree has developed a coat of lichen in many places. Does this inhibit back-budding? Should I remove it? Should I continue to cut back foliage at the branch tips? How much? What time of year? (I live in Zone 5b/6a.)

  2. My second question has to do with how to lift the tree in order to get it into a training pot. The tree has been in the ground for approximately 6 years, and I’m sure the roots go everywhere. It’s been suggested that I cut the roots with a spade all around the tree, wait some amount of time, and then try to raise it out of the ground. I’d like to get it into a nursery pot no larger than 12" in diameter–any larger and I won’t be able to carry it! Does anybody have any suggestions for me? P.S. What time of year is the best time to cut the roots with the spade?

If I can, I’ll put a couple photos below. First photo will show the tree as I acquired it in 2012 (?), and the second (shown from the top looking down) will show the radial arrangement of the branches after removal of unwanted branches and a few years’ worth of trying to encourage back-budding.

Thanks in advance for your advice.


Thanks for posting - this looks like quite a project! I don’t have a lot of experience with spruce, but I can try to address your questions.

  1. In general, spruce aren’t known for lots of back budding, especially on old wood. I don’t know that the lichen is preventing back budding. Hard to say how much if any to remove without a photo showing the areas you’re talking about.

As for pruning, I’d expect this to be a good time of year to reduce the longest shoots. The above shot makes it look like the foliage is quite a ways away from trunk. The tree looks a bit sparse so I wouldn’t want to reduce the foliage by a lot.

  1. Is the tree planted in a nursery container nestled in the ground? You can cut some of the roots with a shovel anytime. The best time to dig the tree up is at the end of winter or early spring.

Hi, thanks for posting the pictures.
1.if your intention is to transplant the tree to a container than i would suggest you retain all of the foliage present. In other words no work prior to digging out the tree!
2.Because of your zone, i would not dig around the rootball at this time. Too little time left prior to frost and freezing for the tree to recover.
3. The best time to collect the tree will be in the spring before budbreak! This gives the longest period of growth for recovery.
4. The governing factor for the size of rootball should be what you find when you dig the tree! You may have to start larger and reduce the rootball over time in order to collect it successfully!
5. If you have the time than i would dig around the perimeter with a shovel to sever some large roots this spring and then lift the tree in the fall. This will give the roots time to recover before the shock of digging it up.

Jonas and Frank,

Thanks for your advice. Considering your combined recommendations, here’s my plan:

  1. Later this fall, seeing how the tree is filling out more on one side (from the one o’clock position to the five o’clock position in the photo above), I’m going to remove all branches on the weak side of the trunk, where there is little evidence of back-budding. This is in line with my emerging sense of how this informal upright tree should be designed: branches with good foliage and progressive taper emerging on one side of the trunk, which will be jinned and carved at the top few inches. I’ll consider adding shari at a later date on the barren side of the trunk where the branches have been removed. This would give me the opportunity to wire the remaining branches (on the “strong” side) more directionally, thereby introducing much more movement to the tree.

  2. See the photo at the bottom of this post for an idea of the amount of lichen that covers this tree. It’s time for that stuff to go! I’m going to use a medium brush to gently remove as much of it as possible around the trunk and on the remaining branches. (Is there a better method?)

  3. In the spring of 2020, I’ll cut back some of the foliage on the strong branches to a) force more back-budding if possible, and b) obtain material that I can graft to empty sections of the branches where needed.

  4. I’ll wait until early spring of 2021 to sever some of the roots prior to lifting the tree in the fall of that year. Hopefully, the grafts will have taken by that time.

Note to Jonas: I acquired the tree in the fall of 2011(?), and yes, the older photo shows the tree still in its nursery pot, dug in for the first winter. The following spring, after I took it to class for the heavy pruning I mentioned in my first post, I removed the pot and planted the tree directly in the ground to encourage growth. It has stayed there for the past seven years or so.

Thanks again to you both, and please feel free to add further suggestions.

Thanks for the info Richard. That makes sense about the potting - the incremental approach Frank outlined is the safest way to go.

As for the lichen, it does look you have a lot. When lichen covers the trunk, it’s impossible to appreciate the bark. The trick is removing it without damaging the bark underneath. If you can pick some or most of it away without removing much bark that might work for a next step.

It’s relatively dry where I live so will be curious if others have approaches for reducing lichen on trees like this.

My area can be fairly damp, when i wish to reduce moss or lichen i bring out a small artists paint brush and apply household white vinegar ( full strength) carefully directly to the moss or lichen. After about three to seven days it dies! ( temperature makes a difference). Then i use a pair of bonsai tweezers to pick off the remains. It is easier to remove when dead and less likely to leave small roots behind that just continue the problem. Very persistent moss often requires two or three applications.
Caution: keep vinegar off other green parts and roots!

1 Like

Thank you once again for your excellent advice, Frank and Jonas. I suspect the large amount of lichen is attributable to the fact that the tree is in a spot that has been heavily mulched–and the mulch is doing its job: retaining a lot of moisture. Once I get the tree into a pot and up on a bonsai bench, I’m sure the lichen will be less of a problem.

So if it doesn’t rain tomorrow, I’m going out to the garden with my big guns: vinegar and a paint brush!

1 Like

I had a huge Piceaa nidiformis in my garden, decades old. I drasticaly cut back the branches , most of which had ground layered, then cut the roots approximately 12 to 16 inches from the trunk.
This was then laft for a year and dug up early Autumn the following year and placed in a huge pot (2 foot by 2 foot by 2 foot full of bonsai soil all inorganic.
The tree is doing very well roots growing like crazy ( container is semi transparent) buds forming but quite small at the moment. I will transfer to a smaller container , but not down to a bonsai pot next autumn wjich seems to be a great time of the year to work on Picea pre bonsai in the UK.
Good luck

1 Like

About backbudding - I have 2 old collected spruce, CO and Black Hills. I let them run all summer and cut back in August. I get good backbudding with this timing here in the mid-Atlantic, zone 7A.

1 Like

per Walter Pall’s method.