Fall Pruning for Japanese Black Pine Trees

by | Oct 29, 2023

When Katsuoki Kawahara, was asked how long it takes to produce a pine tree that appears to be 100 years old, he replied,”One hundred years!

Photo: Portland Japanese Garden Pine Pruning. Photo by Peter Friedman.

Portland Japanese Garden Pine Pruning. Photo by Peter Friedman.

It is true, training pines takes many years to learn, and many more to produce a beautiful tree. However, there are techniques for maintaining pines for Japanese-style gardens to help them appear more graceful and mature. Here are a few basics to start with for Fall:

Black pine thinned for light and air.

1.  Balance

As a pine tree ages, interior and low branches die off from lack of light and energy. Removing needles can reveal the graceful limbs and trunk of the tree and allow light and air to penetrate to the center of the tree and lower branches. Although this may remove up to 75% of food-producing leaf surface, light is able to reach 100% of the remaining foliage, providing even food production and energy throughout the tree. As a result, the tree is able to maintain interior and lower branch health.

The strongest growing parts of a pine are usually the top-most sections receiving the most light.  By removing more foliage from these sections and leaving more healthy foliage in areas where more energy is desired, you can direct growth energy where it is needed most.

2.  Timing

Remove old pine needles in fall, when days and nights start getting cooler and sun on newly exposed branches will be minimum.  In southern Texas, we start in mid November and continue through December if needed.  Spreading tarps on the ground below and over other plants makes cleanup very easy.

Begin at the top of the tree and work down, removing fallen needles as you go. Prune broken, rubbing or damaged branches as you work. Remove all pine cones as well. Grab all the needles and pull back using the thumbs to “rub” them off at the branch.

We will discuss branch selection later in this article.

Closeup of Black Pine branch showing 12 pairs of needles
Katsuoki Kawahara working on pine in Kyoto, Japan

3.  Focus

In Japan and other places were this pine thrives, and on a mature tree in sections of strong growth, we would leave at least 12 or 13 pairs of needles on each shoot.  Areas of medium strength or areas where you wish to channel more energy can keep most or all of this years needles.  Weaker areas and areas needing the most energy may need to keep all healthy needles.

In areas where this pine does not grow so vigorously, leave more pairs accordingly.  If in doubt, err on the cautious side.

On smaller or stressed trees, leave all the current year’s needles in strong areas, and leave second year healthy needles as well on weaker growth areas.

Do not disturb the small buds along and in the old needles as these will be valuable in next years development.

4. Clean Up

After “needling” the entire tree, the shape of branches and trunk can be more easily seen. Remove upward growing shoots except those needed for your training strategy, and leave side and down facing shoots. Whenever there is an upper branch shading a lower branch, one must be removed or redirected so that the other will not be shaded out.

5. Branch Selection

The results of the Spring “candling” should be evident the following Fall. As the weather cools, it is time to select the new branching that will produce next year’s growth. Carefully consider the ultimate shape and size you have decided on before removing any branching. Remember that upper branches may eventually shade out branching directly below. If side branching is desired, choose these shoots first. Then select what will become the terminals that produce candles in the spring. Look for right angles between branches of similar length. Select two for lateral and horizontal branching, and select three for apex and crown growth. Remember that the branching should become shorter closer to the ends of the branches and top of the tree.

Don Pylant, 2005