First develop the trunk, then work on the branches. That’s how I think about bonsai development. If the trunk has yet to reach its final size, I use large pots and encourage vigorous growth. When I’m happy with the trunk, I move trees to smaller pots and focus on refinement.
A number of my black pines turn 11 this year. A few have reached the desired trunk size. I’ve been slowly removing large escape branches and am now ready to move the trees to smaller pots.
In general, if the soil is good, it’s easy to use a smaller pot as the root ball will have fine roots throughout. If not, the tree will have to stay in an intermediate-sized pot until enough fine roots develop to support the tree in a smaller space.
Here are two of the 11 year-old pines I repotted this winter – both were container grown.
Exposed root black pine – 11 years old
11 year-old black pine
After repotting – note how the trunk looks larger in a smaller pot
Yes, Northern California is in the middle of a mild winter and most of my pines are already growing. As I repotted these trees about a month ago, I can start fertilizing now to make sure they’re strong enough to be decandled come spring.
Ever wondered what it’s like to be a bonsai apprentice in Japan? For those who haven’t done so already, feel free to submit questions to Juan Andrade, the Costa Rican bonsai artist studying at Aichi-en in Nagoya, Japan with Junichiro Tanaka, via AMA scheduled for later today (Wednesday Japan time) at Ask Bonsai Tonight.
The shore pine is kin to the lodgepole pine. Both are native to California and parts north, but the exact relationship is open to some debate (see Pinus contorta for details). Shore pine bark is great, if slow to develop, and the needles are relatively short. Not strong enough to withstand decandling, it can be trained like white pine varieties. In fall I remove strong shoots from the strong areas and leave the weaker areas alone. At some point before spring, I remove old needles from the strongest shoots.
I’ve been working on the specimen below for the past two years. As it hadn’t been repotted in some time, I changed the pot after removing the old needles.
Current and last year’s needles
After removing (with scissors) last year’s needles
As I packed up my things the morning of the workshop, I grabbed a pot that seemed to be the right size without looking too closely at it. After working on the tree’s roots, I took the pot outside to clean it and noticed that I’d grabbed a fairly old Chinese container. A bit much for a growing pot? Possibly, but then what’s the fun of saving old pots for exhibits? As the size was right and I’d brought no alternatives, I went ahead and used the old pot.
The old pot
I’ve been happy with the selection since bringing the tree back home, and as it’s a bit larger than the previous pot, the new roots will have plenty of room to grow.
After wiring a bonsai into the pot and filling the pot with soil, I’ll usually give the whole a few gentle taps to make sure I did a good job with the chopsticks. A few gentle taps can quickly reveal faulty chopstick work as the soil will quickly settle in neglected areas. I usually tap at least two sides of the pot while securing the base of the tree with my other hand.
Tap a little bit too hard and the soil can pop out of place leaving the tree loosely secured and requiring starting the process all over again.
For the last step, I tamp the soil into place with my hand. Many wonderful and miniature trowels are made for the purpose, but hands can work well too.
Tamping the soil
Is this last bit necessary? Good question. I’ve noticed that when I water after repotting, the soil tends not to move around as much after tamping the soil like this, and for this reason alone I continue to do it.
Some of the final steps when repotting bonsai are among the most important – especially when it comes to wiring trees into the pot. I typically wire trees into the pot after setting the tree, but when repotting partially or completely bare-rooted trees, I first work some soil into the exposed roots. If no soil is around to hold these roots in place, tightening wires can scrunch roots together, collapsing the rootball and making it difficult to secure the tree firmly in the pot. As I bare-rooted about a third of the roots of the tsukumo cypress below, I filled in the areas between the open roots and around the rootball before starting with the wire.
After adding enough soil to facilitate wiring the tree into the pot
There are several approaches to wiring bonsai into pots, each with their good points depending upon the application. For this tree, I used my default approach for posts with four holes. Taking hold of the front left wire, I brought it to the point where the front right wire emerged from the soil.
Bringing the wire across the front of the rootball
Where the wires meet I twist them together by hand. If I want to make sure the wire is particularly snug at this point, I use pliers.
Grabbing the wire with pliers
If there is a single take-away from this post, let it be this: pull, then twist. If you have ever repotted bonsai with Boon Manakitivipart, you’ve doubtless heard this phrase. The idea is that when tightening wires, first pull the wires tight, then slightly release the tension while twisting. Simply twisting soft wire like aluminum is an easy way to break it. The alternative: pull, then twist.
1. Pull wires away from rootball
2. Lower pliers while twisting
The pull, then twist, approach may be repeated until the wire is snug. After securing the first three wires, you may notice you have nowhere to attach the final wire.
Where does this one go?
Sometimes I plan ahead by preparing a short section of wire with a loop that I can fit around the first wire.
Short wire with loop
As I didn’t prepare this bit ahead of time, I can do it after the fact with a short, hooked section of wire.
I hook this wire under the base of the first wire and then twist it back onto itself.
Hooking the base of the first wire
After securing the wire with a twist
Adding this tail let’s me connect the first wire with the final wire. For this final connection, I always use pliers to ensure the tree is well-secured to the pot.
The last connection
Tightening this last connection ensures the wire is tight across the entire rootball. Once the wire is snug, I remove any excess strands and fill the rest of the pot with soil.
After adding the soil
Two more quick steps – more on that Friday – and then it’s time to water.