Refining and repotting a magnolia (“モクレン”)

Magnolias are ubiquitous in gardens around the world. They mark the end of winter with a spectacular bloom, decorating landscapes in both vivid and subdued tones. My family home has a large magnolia that reliably graced us with beautiful blooms each year while providing a cool shaded understory during the hot summer months. They are among my favorite broadleaf deciduous species and I’m happy to be able to develop one during my apprenticeship here. Lets get to business. For starters the tree:

First to clarify, this is magnolia liliiflora known by モクレン “mokuren” here in Japan. The flowers are big, and so are the leaves. But it’s my preferred variety over smaller leafed varieties like star magnolia. Liliiflora has a smooth cream to white color bark that contrasts strongly with the large and often vibrant flowers. Despite having smaller leaves, the star magnolia has a more subdued bark and less striking flowers. Magnolias are appreciated for their winter silhouette, beautiful bark, and flowers and for those reasons I like liliiflora more. Here is a mokuren displayed during this years Kokufu. I am told by Oyakata that it’s possibly the best mokuren in Japan:

Back to the tree:

closer look
view from the side
right chop where scar is healing
side profile of apex, in the future I want to remove the thick branch in the front

From these set of photos there are few things that are obvious. The presence of a large scar, and an overly thick branch/bulge. Since we appreciate magnolias for their bark we should aim to encourage healthy callous formation to obtain a seamless trunk. To preserve the taper and form of the tree, we need to remove thick branches/bulges but this also introduces new potentially large scars. In order to ensure good callous formation and with some advice from my senpai I decided to only make one major cut. The other branches would remain as “sacrifices” whose collective foliage mass would help heal the wounds. If I did all major cuts at once the existing amount of branches and produced foliage may not be sufficient to heal the wounds. To do so I would have to allow some of the existing fine branching run and grow thick which would introduce more imbalances to be corrected in the future.

With this in mind I decided my “major” cut should be the bulge at the back of the tree:

This would be cut, introducing a big scar. But the large branches above it as well as branches immediate to the wound would aid in callous formation. While the 2 thicker branches to the right ultimately will be removed, the wound created by cutting those branches would be smaller and easier to heal, so for the time being the bulge is prioritized.

There are some concerns with this plan. Since one of my sacrifice branches (branch number 1) is attached directly to my apex, allowing this branch to get too thick can damage the taper of the tree as well as create another future large wound site when I remove it. Because of this I want to distribute the sacrifice branch burden across multiple branches. As soon as branch 1 starts to get too thick it will be cut. Branch 2 will take over as the main sacrifice and will be allowed to run as much as possible without overly compromising the tree’s design. Conveniently there is a small back branch immediate to the wound which I expect to provide lots of callous formation. There are more branches and buds at this base to replace the back shoot when it becomes too thick as a sacrifice as well. This multi-staged plan will help me avoid creating new large wounds while preserving the taper of the tree.

cut and carved

A slight depression is carved into the wound so that when it heals over it is flat without a substantial bulge. If the cambium is ragged after carving, use a grafting knife to cut cleanly across the entire edge. Unfortunately the heartwood on this tree was slightly soft. I wouldn’t say rotted or punky but after debating for awhile I gave in and decided to carve out the dark wood as well. I filled it with a faux wood filler, stuff you can find at home depot for damaged furniture, voids in wood, etc. My brief experience with it is that it takes a long time to dry and harden, especially if there is any moisture content in the wood. I would not recommend it for filling large wounds, in which case cement or a hard epoxy might be more suitable. I will report back later in the growing season if it holds up.

It’s time to inspect the other wound and if the callous needs to be recut. Unfortunately I discovered that the wood at this site was not just dark but actually rotted. I carved out all the soft wood and also painted lime sulfur on the deadwood to discourage future rot or fungal formation. Lime sulfur is bad and damaging to cambium so if you have any open cuts care not to spread it there.

back side callous, after removing cut paste I discovered rot
I began filling in the faux wood paste. Due to my issues with it drying I added it in layers allowing one layer to dry before filling in more
sealed up. Not photographed but later the cambium was recut and cut putty was spread over the wound

The tree was actually repotted prior to doing all this work, but since the repotting season turned out to be quite busy I wasn’t afforded time to bring out my camera and take nice shots. As such I’ve depicted a basic overview of how we repot some deciduous trees here and how I did this tree in particular. During my days as a hobbyist I used a fork I bent in half and take out chopsticks as my sole repotting tools. I would do things a bit differently now. After my first repotting season I’m beginning to understand how nuanced repotting can be and how important it is to properly repot trees so not only an aesthetic, but horticulturally functioning and healthy root can be formed. I hope to make some proper posts on this in the future, but for now here is a basic overview.


My new website template is giving issues increasing image size but if you right click and open the image in a new window, you can see the full resolution.

With the root system and scars set for the growing season ahead it was time to see if we could improve the silhouette or address structure problems.

revisiting the tree

I want to create as many fine branches as possible while minimizing clutter and the formation of bulges. On the left side of the tree there is an obvious density of branches originating from the same spot. The small lowest right branch is crossing and kind of interfering with the branches above it as well.

To begin with I removed one thick branch from this node. While the fine twigging on it added to the silhouette it was creating clutter between the other twigging and ultimately will grow to become a problem area with so many branches originating from the same spot.

small bottom right branch cut as well

Feels much better and less cluttered. My second concern was the most forward branch from that same junction. I felt that there were still too many branches from the same node and that while removing this branch would impact the trees current silhouette, branching and ramification from the branch behind it could easily fill the space.

cut

To compensate I put on some aluminum wire and brought the branch behind it forward. The small twig at the base will develop and fill in the space behind it.

For now the work is done. The sacrifices will be allowed to run and I’ll check on callous formation over the growing season. Growth will be controlled on the smaller branches and possibly cut back to preserve the fine branching needed for the final design. Magnolias will never have super fine ramification and branching so this tree will be styled in a looser “flame” like form similar to a lot of ginkgos and stewartias. I’m excited to develop this tree and will post progress updates in the future.

Small Coast Live Oak

 

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Oak trees are characteristic of California. Abundant and easily found, they decorate the landscape from the highway shoulder to the beautiful canyons and hills. They’re long lived and stand with powerful trunks–it’s that same heft that weighs down their branches giving them qualities unique to themselves.

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Yet despite their seemingly rough appearance the grey bark and dense evergreen foliage lends some grace collectively producing an elegant, proud tree.

As a native tree they excel in my hot Mediterranean climate. Fed well and allowed to grow freely, it will even rival a trident maple in growth. Their foliage is easily reducible and branching can be highly ramified. Definitely one of my favorite trees, both in landscape and bonsai cultivation.

In 2015 I acquired a small coast live oak from Bob Pressler’s nursery (Kimura Nursery). It sat in a small nursery can and was nearly 5 feet tall. Although lacking good branching it had a nice trunk and rough grey barking.

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The tree was fed aggressively to prepare for the repotting and work to come in the following winter. At late winter/early spring I picked a line to do my trunk chop and cut away. Primary branches were left uncut so that they could undergo more thickening before developing secondary branching.

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As for the root mass I sawed the root ball in half and worked the outside. Being lazy I did not photograph this part.

The tree was allowed to recover and by early summer showed strong growth all over the tree. I did some preliminary cutbacks and guy wired all my primary branching into place.

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Early Summer 2016

As you see in the previous photos I had pretty good budding around my chop with buds occurring right up to the cut line. These shoots would become the future leader of my tree.

The tree was again allowed to recover, this time taking much longer considering that in a single season it had undergo 2 major traumas. Oaks typically have a second flush of growth by late summer but this tree had already expended its reserves and didn’t do much.

After removing excess shoots the top leader began growing very fast. I carved the top cut to allow for a smooth transition.

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By fall the tree began thickening a lot. All the carbohydrates and sugars produced by the foliage produce new wood as well as food for next year.

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Wound on top of tree is already halfway sealed–impressive given that the cut was made in the same year

Bark on the trunk began to split as a result of the strong growth. A good indicator that the tree was healthy.

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Several weeks ago I cut back all my primary branching and top leader halfway. I still need the top leader to thicken, but had I cut all my primary branching leaving the leader unchecked the tree would abandon the lower branches and put all the energy into the top growth.

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The wires there were propping up a plastic bag over the tree. I don’t know if it helps but I tend to think that the increased heat and humidity will give me better advantageous budding. In any case, advantageous budding indeed. Every single branch is covered in tiny buds–secondary branching no problem!

I came back from the 2017 bonsai-a-thon today (a post to come later) and purchased a pot from Dick Ryerson. The pot is a round with symmetrical groves. It features a cream glaze with some “dirty-ness” in the glaze. There is a spill of red with a hint of some blue on the side. Although slightly big for my tree it will work great as a beautiful pot to carry it through next several years.

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That’s the pot right in front of me!

I decided that the tree was healthy enough for a repot and given that the root mass in the colander was a similar size to the pot I would not have to do any major root pruning. To fit the tree I cleaned out the center core of the tree slightly–mostly dead roots, organics, and some live tap roots. The edges were very lightly trimmed and the gunky soil from the top of the root ball was raked off.

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The tree was then wired in with the bottom and edges with new soil. The tree is slightly mounded but it can’t be helped as I want to avoid overly working the root mass. As I continue development I will be able to sink it lower in the next year or two.

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As an added precaution the tree was bagged and will be covered for the next week or so to preserve humidity and ensure the new growth and buds aren’t overly affected by the repotting.

This growing season will be used to create secondary branching as well as to finish thickening the apex of the tree.

Here is a live oak developed by Eric Schrader that’s an extremely realistic representation of what my tree will look like in 5 years or so. His tree was inspiration for mine and I hope that in time it will look just as good if not better 😀

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Photo taken by Eric Schrader

I know its been awhile since my last post but I’ve been incredibly busy with school and other work. I hope you find my posts interesting and if so please leave a comment! A subscription is great too

Julian