This is a great time of year to go hunting at local garden centers and home improvement stores for nursery stock trees that will make incredible bonsai for your collection for only a small financial investment. We have been discussing this some on the RMBS members forum, and a recent blog post on RMBonsai.org outlines my method for selecting this material (huge thanks are due here to Ryan Neil of International Bonsai Mirai for the knowledge).
Nursery Stock Sabina Juniper Part One: Root work and potting
I happened to be at a large orange-colored box store this weekend to get some gravel for my garden and just couldn’t stop myself from picking through the stock of medium sized junipers there for sale. I happened upon a tree that was suitable, and the price was right. $25 all in. If nothing else, stock junipers are great to get “some turns” for wiring practice and make very attractive trees, even in small size.
I have never worked with juniperus sabina before, but I think that the common juniper bonsai techniques will apply. I have seen some Sabina juniper bonsai from Europe that are very desirable specimens.
Typical nursery tag with very little usable horticultural information.
I chose this tree because it had a single trunk (not a clump) and the trunk made two very distinctive movements that added interest, and an overall style that lends itself to a semi or full cascade (which I have very few of in my garden). Beyond this, there is very little to recommend this tree or distinguish it from the 30 others I reviewed on the shelf. It will make a good bonsai, not an exceptional one. All told, I will likely have a tree worth a couple hundred dollars from an investment of about one tenth of that.
Looks like every other bush on the rack at the box store.
At least the trunk has a bit of interesting movement. Not much else to recommend this stock.
Step one: Assemble tools and usable workspace. Knock it out of the nursery can and start reducing the soil mass with a chopstick. As will most nursery stock, this tree was completely pot-bound, with numerous large roots encircling the can. This tends to be easy work, and you should work starting at the top and pull radially from the trunk toward the outer ring of the root mass. You should start from the top and work down to identify the true nebari (basal root flare). You will need to remove diminutive roots that emanate from the trunk above the larger basal root flare: this is easily accomplished with scissors. As with many stock juniper, the nebari on this tree was not readily apparent, but I was able to get to some large roots all emerging from about the same area. This was about 1/3 or a bit more down into the nursery can.
Step two: Once you feel you have identified the true basal root flare, start working the bottom and sides down to a reasonable mass with the same inside-to-outside chopstick technique and removing unwanted roots with a scissor, assuring sharp clean cuts. It was helpful to have identified a usable cascade style pot and to dry fit the root mass periodically to see if I had reduced enough. I think all together, I took off about 50% of the existing root mass, focusing on removing long, stringy roots that were coarse and without a large mass of fine feeder roots.
Root mass after working, prior to potting. Lots of fine roots remain. Basal flare identified.
Step 3: Prepare the pot with drainage screen and tie down wires. This pot posed a problem (which is a common one) with only a single drainage hole at the bottom and no other areas to string tie wires. I will omit the primer on proper potting here but show you how I tied this tree down using a bar of heavy gauge copper wire, clipped to length and stainless-steel tie-down wire (will not stretch). I inserted a chopstick into the root mass above as an anchor to tie half the tree down (again, a topic for another message).
A common tie-down wire problem: remedied.
Step 4: I potted the tree with a layer of coarse aeration soil at the base (same composition as the rest of the soil, just a fraction larger). I tied the tree down loosely, then filled the pot with soil. Pushing the soil first in around the tree with my fingers to “bulk-fill” the spaces. Then I tightened the tie-downs snug once I had the tree at the angle which I thought was suitable for the next 2-5 years of training. After this, I filled the pot with more soil and chopsticked in the rest of the soil to eliminate all of the empty space in the container. I top-dressed the surface with mountain moss (to keep the soil from being displaced when watering). All told, a bit more than one hour of root work and potting done. This tree is now ready for the heavy styling work in the coming weeks. The ability to both pot and style a tree in a single season is a huge benefit of nursery stock.
Ready for styling. After root work and potting.
Nursery Stock Sabina Juniper Part Two: Primary Styling
Let’s pick up where we left off last month following the selection, root reduction and potting of a humble (cheap) nursery stock Sabina juniper from a large box store. This month will we will see the culmination of the project to the “initial stop” following primary styling. This will leave the tree in its developmental stage but set up for a long and pampered life as a bonsai.
First, a word or two about the scope of work and the timing of this project. I have witnessed professional bonsai artists take a pre-bonsai, perform heavy styling work with large bends, deadwood creation followed by potting the tree in a suitable bonsai container. This made me wonder: did the tree die after this? Were they severely stressed? Do these trees need exquisite after care? Of course, the trees always did fine. The pros know what they are doing. However, this does fly in the face of the traditional teaching: one major move a growing season. You pot or you style. Not both. Wait for next year. While this tradition does ensure success and allows a tree to maintain health and vigor, I wanted to give the “full demo” a try. To be fair, I have done both potting and styling in a single sitting with success in the past. This is what Will Kerns likes to refer to as “race-pace bonsai.” An instant transformation. None of that pesky waiting.
Here are some considerations that you need to take on board if you want to try to put the “pedal to the metal” yourself.
1) Nursery stock is pot bound and often tolerates both root and significant shoot reduction in a single sitting to match the new “root / shoot” ratio. Stock trees are your best bet. Collected bonsai have less predicable root systems and often warrant additional respect (patience).
2) Consider “slip potting” into a similar sized bonsai container and leaving the root system untouched while focusing on styling. This is usually not possible with something in a large nursery can, as is the case with our tree. This more closely approximates the “one move a season” rule.
3) Timing is important. May or June is a nice time (late in the potting season, early in the styling season for conifers) and this allows the tree plenty of season to repair roots and set buds prior to the autumn freezes. Don’t do this late in the year unless you have great winter protection (greenhouse). I’d avoid doing this after mid-summer here.
4) Choice of species matters. Many deciduous and some confers can tolerate this treatment. Junipers are a nice selection, as they are known to tolerate root reduction well if a good amount of foliage is maintained. Pines can be more finicky about their root systems and are likely to be a chancy choice for the race-pace technique.
5) Aftercare and winter protection are key. You need to consider both these items prior to slapping a stock tree into a small container and chopping off a bunch of branches. You cannot just park it on the bench in the sun next to your other trees. You need to have a cold frame, unheated garage or greenhouse to protect from heavy freeze the first winter. You also probably shouldn’t head out of town for a two-week vacation right away either.
Now, back to the work at hand. I had already reduced the root system to a nice set of fine feeder roots, identified good basal flare and potted the tree in a training container with the correct angle to create a cascade style bonsai.
I accomplished the remaining work in 2 sessions, both occurring about one week after potting. The first was about 3 hours of deadwood creation, major branch selection and wiring to create the primary style. I focused on trunk line and feature branches such as the long cascade (primary) branch which sets the tone for the overall style of the bonsai. The second session was all detail wiring and detail pruning. Another 3 hours. I focused on creating space between foliar masses and foliage pad creation.
1) Deadwood creation: I chose low branches that had poor ramification and interfered with the placement of the cascade / primary branch. This area also adds interest to the base of the trunk and the overall trunk line. I started by removing foliage on the offending branch, crushed them with jin pliers and stripped away the bark. Then I wired to given them some shape. This can be done when a living branch that becomes jin, and they will set in place by the end of the year and the wire can be removed. No lime sulfur treatment currently. I will let them age naturally for a year or two.
Deadwood and jin created
2) Primary (defining) branch setting. Usual custom is to begin from the bottom of the tree and work up. The low cascade branch was the first one I set with wire, as it would define the character of the tree and set the “tone” for the branch angles and pad placement which would follow.
Primary cascade branch sets the tone for other branch wiring
3) Set counter branches: These foliar pads were kept shorter on the left side of the tree to keep the overall movement and flow to the right, however they are important to create balance and a sense of stability.
Counter branches add balance while maintaining asymmetry
4) Work up to the apex: Selecting branches that emerge from the correct locations where you’d like to have foliage mass. All the branches should be placed to maximize photo synthesis and have their own “space” in the design. This will allow for development and growth prior to the refinement phase of the tree (many years away). Look at which side the branches emerge from the tree and maintain the correct orientation. Very few should be bent back “across” the tree or have this relationship significantly altered. The apex almost always occurs from the top-most branch on the tree and apex creation needs to be considered early on in styling. Ask yourself: which piece am I going to use for the apex? Work your way up to that. When viewed from above, the bonsai should have a radial shape with branches emerging all around. Not a one-sided tree.
Apex viewed from above with radial branching pattern
5) Final adjustments and fine wiring. Foliar pads should be shaped and shoots selectively reduced to accomplish this. Almost every piece of growth was detail wired on this juniper. All should be placed accordingly, and frequently take a step back to consider the overall feel of the tree. My goal was to try to showcase the interesting trunk line and movement show below.
Showcase trunk-line and movement
6) Initial stop and aftercare: This tree was moved to dapped sunlight in the morning and shade after 1pm for a couple weeks. Close attention has been paid to watering and I have not let it dry out completely. I also have foliar fed (misted) the shoots with a dilute miracle grow solution (1/4 strength) at least twice a day for the first month. It has recently been moved back to full sun and closely monitored for watering needs. Foliar feeding can likely cease in the coming months. It will be wintered in my unheated garage this year to prevent freezing.
One month out from heavy work. Juniper hasn't shown any ill signs
This tree will be fertilized heavily until October. No other work will be conducted. Next season, new growth management and refining the foliar pads into more individual masses will be my focus. Stand by RMBS member Dan Kingery.