I recently purchased a miniature Brush Cherry nursery plant to convert to a bonsai specimen. It's doing well and loving it's new pot and increased sunlight in contrast to it's previous life in a pot shoved in a corner behind taller trees.

I know compacting the foliage of a bonsai can take many growing seasons and I'm up for the task. My question is how far should I prune to induce back budding closer to the trunk? The idea is to obviously produce tight ramification through continuous pruning. My tree (see picture) only forks at the end of the branches though.

Should I prune the old wood branches back hard in early spring to produce leaves closer to the trunk? Will pruning off the ends with all the leaves potentially kill the tree (I know timing is crucial)? I know Brush Cherries are very hardy, but I don't want to push the tree too hard at once. I plan on caring for this tree for many many years to come, so I'm willing to go slowly. I just want to make sure that I'm using the proper pruning technique for this particular tree.

For a sense of scale, the tree is roughly 20 inches high including the pot. Thanks everyone!

I would be thinking of chopping this tree just above one of the two lowest small branches - which ever one gives you the best trunk line after wiring them into place. I would wait until spring to do it, not pruning anything for now, other than what it takes to ensure the branch you select as your new leader is getting enough light. Then, I would continue to develop trunk taper through a series of sacrifice branches over the next several years. Watch the sacrifice branch - when it starts to get so large that you can see a collar developing around the leader you've chosen, it's time to remove the sacrifice branch & start developing another. I usually have 2-3 sacrifice branches planned ahead, so when the lowest is removed, there is another ready to take its place.

This plant back-buds very readily, so you CAN cut a healthy individual back severely with no problem. I would wait though, until at least Memorial day to do any significant pruning. If you're going to repot it in the spring, I would probably do the repot (without any pruning) around mid-May to Mem Day, then do your pruning once normal growth has resumed. That way, you take advantage of the tree's maximum ability to make photosynthate (food) to support root regeneration after the repot.

Al

Thanks so much for your reply. I really appreciate the explanation. The trunk taper (or lack thereof) is the only thing that bothers me about this tree. Like I said, I plan to have this tree for a long time, so I'm willing to put in the years of effort to develop a really great bonsai.

I've been studying my tree for the past few weeks to consider all of my options for future development. I also bought another brush cherry of similar height, and I plan to do some drastic pruning at some point during the next growing season. IMO there are more development options with the pictured tree (in this post) than the other since there are two trunks. I'm considering leaving the left trunk as the apex and the right as a shorter slant. Any suggestions from a more experienced eye?

Thanks again!

If this was my tree, I would reduce the daughter tree today, by removing the vertical branches that won't be part of the composition. This plant tends to grow in tufts of foliage at branch ends just behind pruning cuts (like burning bush), so (on the daughter tree), I would remove any end 'tufts' that have multiple branches so there are only 2 secondary branches growing from each main branch. Concentrate on developing only horizontal branches you'll be keeping as part of the future composition. Let the mother tree grow unencumbered by pruning. ANY branches you intend to keep should never have more than 2 branches emanating from any single point - IE, Y's are ok, but 3 branches from the same point will give you trouble down the road because of reverse branch taper, so correct that as soon as it's reasonable to do so on both trees pictured in your posts.

As you develop the top of the mother tree, keep in mind it will want to overhang the smaller tree protectively, so as you prune & wire, the main tree will want to move from left to right, as seen now - if we're looking at the best 'front'.

One of your tree's most attractive features will undoubtedly be its roots. Experienced judges of bonsai material look there first, so start working on the roots at the first repot time. Reduce heavy roots the most & allow fine roots in the right places to grow unencumbered by pruning. If you lack roots in a particular spot where roots are needed, get after stimulating root growth in that area and work toward a horizontal root system and roots of equal size/spacing.

This picture (above) is actually a preparation for layering off the top of a Carpinus koreana with poor roots, but just filling the holes (done with a brad-point drill spun in my fingers) with rooting gel will produce roots where wanted. If your tree has enough trunk below where the two trunks join, it's a good candidate for layering.

See this maple's nearly perfect root structure after layering:


You can still see the wire I used as a constriction to block the downward flow of photosynthate to roots, which caused a high level of carbohydrates (to enhance rooting) and a nice swelling (trunk flare) to occur immediately above the constriction. I do this to a LOT of trees with weak root systems - it's much easier than fixing them.

This is a very impressive root system (Acer b) for such a very young tree - done by drilling the holes & layering off the top - as you saw in the pics above.

Any back-budding that occurs low on the trunks - let those branches grow to increase lower trunk diameter. You can remove them later, after they've done their job, but if they occur very close to each other, eliminate one of the branches to reduce swelling and reverse taper. This goes back to the 'no more than 2 branches emanating from any one point'.

Al

This is really really good advice. I appreciate you taking time out to couch a novice. All of the "bonsai nurseries" that I've visited in my area don't seem interested in these types of discussions. I've only gotten blank stares when asking these types of questions. I only get, "I don't know, we just sell them. I can't tell you what to do with them after." I've scoured the internet and bought multiple bonsai books. It always seems easy to "see" an already styled tree, but less so with nursery material. I digress...

I'm going to take your advice and get rid of any non-Y branches and I think that'll help my focus the design some. My design judgement was thrown off when staring at the "mother-daughter" tree since the apexes are roughly the same height. My eye gets drawn to both equally which makes the tree less interesting (i.e. no flow in the tree).

The root development was something that I knew I would have to tackle at some point with this tree. I'm not sure I'm quite advanced enough to attempt what you've done in your post; however, I'll save the example for the future when I'm more comfortable. I noticed that there are cuts at the base of the mother tree where a branch used to be so I'm hoping another will appear to help fatten the trunk.

I'll snap some picture in a little bit after I do some work on the tree. I'll have to contemplate my cuts over a beer and then use the liquid courage to make the cuts. Again, I really appreciate your help!

Also, a new 1 3/4 inch high pot should be arriving for this guy this week. My hunch is that I should wait until May to give it its new home since I've stressed it enough by pruning hard. I know it's another rookie mistake to rush pruning and repotting so I'll try to take it as slow as possible.

I welcome any critiques and criticisms of my handiwork.

You should hope for a branch to break from the scar on the right trunk half way between the soil line and the first set of branches. If it does, wire it carefully into place & let it grow unencumbered until it thickens. Then remove the branch above it that moves to the right front. I'm assuming that branch is part of a pair of branches both coming off the trunk at the same point - just opposite?

The first branch occurring off the left trunk should be wired flat. If you don't think it will tolerate the wiring, wait for another branch to break off of that branch and wire the smaller, secondary branch flat or slightly downward.

Here is one in the process of being built. In the first picture, I've already removed a large part of the top that served as a sacrifice branch. The basal sprouts and back branch help to thicken the trunk.

I covered the rearward growing sacrifice branch.

I have 2 main branches & a back branch (hard to see) positioned, and two potential new tops, plus all the new breaks that will occur between now & spring when I do the first repot.

Ugly as sin now, but in 3-4 years it will be ready for a pot.

Al

I agree with you -- as soon as I removed the right-facing branch on the right trunk I knew it was a mistake. Looking at how vertical the one I left is, it's easy to see the other should have stayed. It sort of messes with the overall flow of the tree. As you said though, I can choose a right-facing branch off the vertical branch to be my new leader.

I will also eventually remove the lower front symmetrical branch to create some interest once I get another branch sprouting from below. The lowest left facing branch on the left trunk can tolerate wiring, I'm sure. So I'll make sure I place it in a more horizontal position. The newer growth on brush cherries seem to be alright with moderate bending, although I have lost a couple of smaller branches on my other tree from being too ambitious. Lesson learned.

One question about your brush cherry. I see the sacrifice branch in the back and I understand its importance in fattening the trunk. My question: do the shoots growing out of the root surface contribute to the same effect, or do the new shoots sap energy that would otherwise go to thickening the main trunk? It seems like the shoots would have to share energy with the main tree and would therefore slow the progress of building a trunk. Just curious -- your advice is well appreciated.

Thanks again,
Tom

I'm envisioning the four top branches as the canopy with three distinct foliage layers at each branch "tier." I think this is doable, but some of the layers are very close together, so it may be difficult to build much structure at each level.

I welcome any thoughts -- thanks!