Tag Archives: Fall

Fundamentals of Bonsai – Pruning

There are hundreds of questions on bonsai forums, at clubs, and across the globe about pruning. What to prune, when to prune, why we prune, which species can I prune now, how often do I prune, etc. I want to help clarify these questions.

 

I’ll start with explaining why we prune. There are 3 main reasons to prune:
  • Cleaning
  • Controlling Growth
  • Improving Structure
     We clean to improve airflow and allow sunlight to penetrate into the interior and lower branches. This is also a precursory action to wiring and styling the tree. Trying to wire a tree without cleaning it first can be miserable, especially when doing it on a needle juniper.  Cleaning consists pruning off weak interior growth with little to no ramification and  clearing any foliage in the crotches between the trunks and branches. This includes leggy branches that are not developing in the desired direction.
     Pruning is the way we control growth on our trees. This is how we tell the tree to direct more resources towards a specific branch or section of the tree. This helps to keep your branches a specific length or thickness and give them directional movement to draw interest. This is also the technique we use to gain width in certain branches and keep others from thickening too much. I will go into more detail later on how to do that.
Structural pruning is the way we improve taper, inverse swelling (taper), direct the line of the trunk and branching, and remove flawed or unnecessary branches. Being able to prune effectively is the foundation of successful bonsai practice and design.

 

Before we go pruning anything we need to step back and observe a few things about the tree we’re about to prune. We need to identify:
  1. What species is the tree?
  2. What is the tree’s current health?
  3. Did you repot the tree within the last few months?
  4. Why am I pruning?
  5. Is the ______(tree, branch, etc.) that I’m about to prune in refinement or development?
  6. What season are we in?
  7. What is the effect on the tree’s energy and health if we prune now?
1. Some species hold significant amounts of energy in certain parts of the tree. Junipers hold significant energy in the foliage. When someone interested in bonsai buys a juniper and then prunes a lot of the foliage off they frequently die, this is why. Pines hold their energy in the roots. Deciduous trees hold theirs throughout the tree. Other species have certain timing for an additional flush of growth (Japanese Black Pine) or timing to prune for flowers.
2. If the tree is not healthy, don’t do any work on it unless it involves solving the health issue.
3. If you recently repotted the tree you should avoid pruning so that the foliage mass can help restore the root system that you worked on.
4. The purpose of pruning can include any of the aforementioned reasons – improving structure, controlling and directing growth, or cleaning.
5. We need to understand the stages of bonsai. If you’re not sure what stage your tree is in do some research before.
6. What season we are in can be a great factor in determining if we can prune without damaging the health of our trees. With most coniferous, deciduous, and broadleaf evergreen species the seasons function in the same way. Winter is a period where the tree doesn’t metabolize freely and we often refer to it as dormancy. Spring is a period of heavy growth. There are several periods of using the trees resources to produce more growth, then gaining those resources back through photosynthesis. In Summer some trees can go into a Summer dormancy if the temperatures get above 90° regularly. If you are in a more mild climate your trees may not slow down growth completely. Fall is a time where the trees save energy and focus on thickening branches and roots to help with Winter hardiness.
7. An example of a bad time to prune would be in Spring right after your tree has pushed out a ton of new leaves. If you prune the branches off before the leaves have been able to form a cuticle (finish growing) and reaccumulate energy, then you’re weakening the tree by taking away its ability to gain energy back.
A generally safe bet is the prune in early Spring before buds pop open or additional candles / needles start growing.
I’d like to also state that you can operate outside of these general guidelines, and depending on how you care for your tree afterwards, you can prune at almost any time. However, I would not recommend pruning whenever you please without extensive knowledge and experience.

How To Properly Plant A Tree

Properly planting your tree is critical to maintaining a healthy tree for years to come. Incorrectly performing one or more steps can set your trees growth back years and might eventually lead to its death.

  • To start you’ll want to make sure you aren’t digging into any utility lines beneath the soil.
  • Follow that up by checking for mature tree size and make sure to give it enough room to grow vertically and horizontally without any interference.
  • Dig a hole as deep as the root ball and 2 to 3 times img_3237as wide as the root ball. 
  • Check the drainage to ensure this is a good planting site. If necessary modify the hole for better drainage or change the planting site.
  • Remove the tree from the container and place the tree on the ground.
  • Remove soil from the top of the root ball until the top of the main root system is visible. You should see several pencil thick roots emerging from the trunk. You may have to remove up to 4 inches of soil.
  • Remove any small roots above this point and any roots that circle around main roots as they can cause significant damage in the future.
  • Backfill the hole to this new soil line with the root ball placed inside with 50% native soil and 50% soil amendment.
  • Assure that the root ball is not covered with soil above the top of the root ball.
  • In the High Desert be sure to stake the tree.
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There can be several inches worth of soil before finding the root flare.

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This is after removal of the fine roots above this final soil line.

 

Removing the soil is a critical step to providing your tree with the highest chance of survival years down the road. Failure to do so can result in roots choking each other out when the tree ages like the tree below.

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Bare Root Ruckus

My bare root adventures started off very exciting. I had one company give me an estimated date and another company gave me a tracking number. I had planned for 100 Japanese Black Pines to arrive somewhere between 2:00 pm and 8:00 pm. While waiting, I received another 200 trees that I wasn’t expecting for another week. I ended up planting up the 300 trees from 2:00 pm to 11:00 pm.

These are the different instructions I got from both companies:

Open when ready, and…

Open this right away!

This led to my kitchen being piled up with wet towels, needles, and ginkgo leaves.

I ordered 100 Ginkgo Biloba, 50 Bald Cypress, 100 Japanese Black Pine, and 50 Colorado Blue Spruce.

Ginkgo Biloba and Bald Cypress Seedlings

Japanese Black Pine Seedlings

As you can see, the root systems varied a bit, but this is due to the differences in age, growing locations, and species. The Japanese Black Pine were grown in plugs and transplanted into the field. The Colorado Blue Spruce were grown for 7 years, 3 in the seedling beds and 4 in the field. The Ginkgos and Bald Cypress were both grown in seedling beds for 4 and 2 years respectively.

The Colorado Blue Spruce had pretty solid root systems and size.

Colorado Blue Spruce Trees

Japanese Black Pine Seedlings

I picked a few of each species to grow out in a mound of compost in the backyard. I’ll give an update on survival and how each species transitioned from the bare root process. Overall I was impressed with the size and roots of the trees that I received.

Plans For The Elm

This elm had a rough year. I was hoping to get better ramified branching this year after repotting, but instead of ramification and smaller leaves I got long internodes, vigorous growth, and a near death experience when I left for vacation.

I have this blue pot that I’m excited to combine with the yellow color of the Fall leaves on this Elm.

Both the trunk and the pot are pretty feminine in design, and will compliment each other nicely once combined. The smaller size of the pot will help to facilitate smaller leaves and internodes. Hopefully I can get a bit more progression in refinement this next year.

Privet Dig

I got lucky in being able to dig up two large pom pom style wax leaf privets up from a friend. There was also a stumped one that looks like it’ll turn out great. Here are some of the before photos:

I guess this is sort of a before picture… I also got the little one out so fast I didn’t really think to take a before photo.

One of the things that makes these so good to dig up is that they’re pretty dang indestructible. I have transplanted these in mid summer without any damage to them. The really thick cuticle on the leaves give it a tremendous ability to hold water without losing it through the leaves.

I was very pleased to realize these bushes had been watered really well (which is rare in the desert) and I pulled back the plastic while digging and saw a wonderful mat of mycorrhiza.

Another shot of the roots:

In bonsai you don’t always see this on the surface, but you should hope it is in the roots when you repot. You can encourage the growth of mycorrhiza with organic fertilizer. This is one of the reasons that organic fertilizer is preferred over chemical fertilizer.

Here is one of my tea bags that is breaking down with organic fertilizer inside of it.

Once I got the bushes out I had to transport them home….without a truck.

I got them into larger pots once I got home. The plan is to let them grow while air layering each pom pom off in the Spring.

Portulacaria Afra Behemoth

I decided to work on a few Portulacaria Afra trees. Practicing wiring on these trees is great due to the spacing between leaves and branches. This first little guy didn’t need too much wire to set the structure.

When it is repotted it will get a slight angle change.

Keeping the lower right branch to help thicken the trunk as a sacrifice branch

The next P. Afra that I worked on was the behemoth that I got for $5. I decided to be indecisive. The design I have in mind has me cutting off several larger branches, so I wired it to open up the possibility of growth, while not shutting off the idea of keeping the branches or cutting them off.

The pad formation from bird’s eye view.

Another shot from above. I was able to wire two branches with the same wire which allows for the tree to have a total amount of less wire on the branch for better aethstetics.

Everything from above.

The end product. I have an idea of what I want to do, but we’ll see as we go forward.

I want to cut in 4 places and end up with two large informal uprights, a good cutting from the back, and a cascading branch that can be worked for a few more years.

Fundamentals of Bonsai: Fall

Fall is an important time in bonsai. This is where we direct our trees to do as we please. Fertilization, future cold hardiness, and girth in branches and trunks all come during this time.

Vascular Growth

Vascular growth is what the tree focuses on in the Fall. This means that producing leaves is not the priority since we aren’t going to be photosynthesizing much in Winter. All energy accumulated from the photosynthetic process go to storage in the trees cells. This energy accumulation is what drives the Spring flush of growth. Different species store their energy in different places. Pines are typically in the roots, Junipers are in the foliage, and Deciduous trees are evenly spread in the roots, trunk, and branches.

Cold Hardiness

There is also an important nugget of information about cold hardiness. In bonsai we love the highly ramified branches. In order to get those twiggy branches we reduce the cold hardiness of that branch. The more sugars and starches we have inside the branch of a tree, the lower the freezing temperature is. Therefore, highly ramified branches are highly susceptible to cold damage even though the tree as a whole might be able to withstand a much colder temperature.

Energy Management

Energy management is of supreme importance in the Fall. The more you fertilize the more energy the tree stores. When a tree has a lot of energy it produces long internodes, large leaves, and coarse thick branching. When a tree has a small amount of energy it produces short internodes, smaller leaves, and fine twiggy branching.

This is why following blanket statements about fertilization can be so dangerous. If you just fertilize every 4 weeks with a full dose every year, you’re never going to be creating a tree with highly ramified branching and small leaves.

Wire Bite

If your tree is wired, this season must be a watchful one for you. Wire bite on the branching of trees most commonly happens in the Fall due to the trees focus on vascular growth. Checking the branches frequently allows you to stay ahead of the trees growth and remove wires before it damages the branch.