The Buzz

Pinus thunbergii (Japanese Black Pine) Pruning

May is a busy time of the year in the garden.  There is a plethora of planting, including annuals, perennials, trees and shrubs. The education staff is busy teaching students all about our world and the plants inhabiting it. Live at the Garden is ramping up for a busy season, and weddings are constant. All of these activities are vital to the garden and its continued growth, but in my humble opinion (granted that it is VERY subjective), one of the most important tasks to accomplish during this busy month is the pruning of the Japanese Black Pine.

  Pinus thunbergii is a gymnosperm (non-flowering plant) native to the coastal areas of Japan and Korea, tolerant of the constant salt spray that accompanies these sights. The needles on this pine occur in pairs and are dark, lustrous green, ranging from 2 ½” – 4 ½” long, and typically persist on the tree for 3-5 years.  There are a handful of cultivated varieties (cultivars) in the trade, with one of the most popular being “Thunderhead,” but it is this gardener’s opinion that the straight species is the most typical to come across, easiest to grow, and the easiest to work with.

Most of the pine trees located in Seijaku-En, The Japanese Garden of Tranquility at Memphis Botanic Garden, are Black Pine, but we also have specimens of Pinus densiflora (Japanese Red Pine), P. strobus (Eastern White Pine), P. parviflora (Japanese White Pine) and peripheral plantings of native P. elliottii (Slash Pine) and P. taeda (Loblolly Pine.)

Why do we prune Black Pine during this busy time year you ask? The simplest answer is that the candles, new growth, are elongating and we can control the trees growth, and more specifically their direction of growth, by either shortening or removing them. Candles on Black Pines typically come in groups of 3-4, though on more aggressive areas of growth, such as the top of the tree, you can see bundles of 5 or so.

So, why bother to prune the trees? For one, it regulates the size. Black pines, if left to their own accord, can grow to 40-50’ tall with long sections of growth. The pines in our garden range from 2’ -25’ tall, so we want to keep them small with more compact growth. Secondly, we want to style the tree in a Japanese fashion in that they look similar to what you would see along a sea coast; contorted by the constant harassment of the elements. This makes the trees look windswept, dwarf and contorted. Pruning also helps different parts of the tree either grow or not grow. Realizing that this might not make a whole lot of sense, let me explain. The top growth of trees is typically the most robust.  It has the most dominant leaders (growth) and receives the most amount of sun. By thinning (pruning) the trees, we open the canopy up, letting rays of sunlight hit the lower branches and in turn producing more growth. Having this more open canopy also allows more air movement which helps with pest and disease issues. The overall effect of the pruning on the tree is a dwarfing similar to what you see in bonsai.

I have only scratched the surface of this whole process in this blog post. There are many other elements to consider when pruning that are only learned through rigorous study and practical experiences. If you are interested in learning more on the art of pruning Black Pines, please feel free to contact me, as I am always looking for volunteers. (I have a lot of trees to prune!!)

Nick Esthus Curator of Seijaku-En
nick.esthus@memphisbotanicgarden.com  

Posted by nick esthus at 2:07 PM

Comments

9/12/2013 at 12:58 PM by robert ichikawa

thanks Nick for the information. i will post follow-up with results after pruning my two black pines,


2/20/2014 at 07:00 PM by Ligia

I have 5 Japanese black pine I live in Southern California, my pines are about 16 feet tall, is it good to prune about two feet from the top? And is the month of February a good time to start doing this, should I wait until I see more candle growth?


2/21/2014 at 11:01 AM by Nick Esthus

Ligia, Black Pines are very tough trees and can handle some severe pruning. The type of pruning that you are looking to do can be accomplished anytime of the year, but winter is probably the best time. I will say that I have no experience in pruning in Southern California so it might behoove you to ask a more local source. I would recommend checking out the North American Japanese Garden Association's (NAJGA) website, najga.org, to find a more regional source to ask their opinion on the matter. Hopes this helps, Nick


5/9/2014 at 03:31 PM by Ligia

Thanks...I did some thinning and pruning during March....they look beautiful, but next Fall or Spring I will have to get them shorter they are getting too tall for me....


6/30/2014 at 12:46 PM by Doug Currie

I have two Japanese Black Pines that are about 30 years old. They have not been pruned over the yearsv so they now have long horizontal branches with the candles at the end of the branches. If I cut these back these branches, can I expect candle growth on the areas that may have some needles but no candles? This is in Maryland, so perhaps similar climate to Memphis. Thanks Doug


6/30/2014 at 12:47 PM by Doug Currie

I have two Japanese Black Pines that are about 30 years old. They have not been pruned over the yearsv so they now have long horizontal branches with the candles at the end of the branches. If I cut these back these branches, can I expect candle growth on the areas that may have some needles but no candles? This is in Maryland, so perhaps similar climate to Memphis. Thanks Doug


9/16/2014 at 08:15 AM by Eve Dorfzaun

Love Japanese Black Pine. I have a sunny but windy at times terrace in NYC. Can you recommend a source to purchase? Thank you,Eve


9/16/2014 at 12:50 PM by Memphis Botanic Garden

Eve, Rick Pudwell, Director of Horticulture, suggests looking for a website for Mark Pitts, of “Fantastic Plants.” He operates a mail order business and sells conifers and Japanese maples. We're not sure of how to get in touch, but Rick is familiar with his name. Hope that helps!


12/4/2014 at 01:30 PM by Golden Carp Designs

Thank you. Will you please explain about pruning the leader branch, especially in the first few years: the effects and benefits of doing so, and so on?


12/16/2014 at 02:43 PM by Nick Esthus

Doug, Sorry for the very long delay to get back to you. I meant to write back sooner, but sometimes I forget and 5 months later I remember. Anyways, sorry. Regarding your pines, since your pines have never been pruned, or at least not for a long time, I would start with a general reduction pruning. What does this mean? Rather than pruning the buds or candles, start pruning branches out. What to look for? Start with some obvious choices, dead, broken or injured branches, branches that are crossing and creating wounds on one another. Next, start looking for branches that are redundant with others, meaning branches that seem to occupying the same space. Think about future growth and where it might grow. Next, look at the spacing of branches off the trunk. Look for pleasant lines and good spacing. The overall goal would be to reduce the overall size of the tree and to make it look older than it actually is. You will not, however, be able to accomplish this all at one time. Standard pruning practice says to take off no more than 1/3 of the tree at one time. This is not a hard and fast rule, but a good guide line to follow. In the following years, you could start doing more of the candle work that is described above. Remember, trees are patient, so it only makes sense that we are as well when working on them.


12/16/2014 at 03:04 PM by Nick Esthus

Golden Carp Design, As far as pruning the leader of a tree, I would be cautious. Let's do some simple, general plant biology. The leading growing tip is called the apical bud; think apex. It is the very top of the plant and leads the growth. This bud also contains high amounts of the plant hormone auxin. Auxin is a type of natural growth regulator and also helps control which branches grow faster, stronger and so on. When you take out the leader, or make a heading cut, you affect how auxin is distributed throughout the plant and several reaction will occur. First, another branch will want to become the leader. You see this reaction when a tree has naturally lost its leader from a storm or utility company. A lower branch on the tree will either turn from lateral to vertical, or will develop water sprouts, which are dormant buds that pop when there has been a sever loss of plant tissue, i.e heading cut. This is both good and bad; good in the fact that the plant is healthy and developing new tissue; bad in that this new tissue is usually weak wooded and does not originate from favorable locations. So lets talk about your pines. It really is case specific. What are your goals for your trees? Their location? The movement or feeling you are trying to evoke? The nice aspect about pines is that since the top is so vigorous, you can usually prune them pretty hard and get good budding below, but this is on more established trees. In your case with young trees, you might get a lot of buds to push if you make a heading cut, or you might not. If you have the means, I would try a few heading cuts on some young pines and see what happens. When you make your cut, be sure to cut to a lateral branch as this is where your wound will heal over. Good luck, and keep me informed as what you decide.


3/8/2015 at 06:14 PM by Diego Suarez

I have several Thunderhead Pines in Eastern Washington State. We had a very rapid change in weather last Fall and it got extremely cold for about a week. My Thunderheads turned brown at the ends of the branches as if they had been frost bitten. They look really bad right now but the new buds (candles) are coming out. What should I do to improve their looks? Would the browned out needles eventually fall off? My pines are about three feet tall so I don't want to prune them and lose height. What do you suggest or should I just wait it out until they get all green again? Thanks for any advice you may offer. Diego


3/8/2015 at 06:15 PM by Diego Suarez

I have several Thunderhead Pines in Eastern Washington State. We had a very rapid change in weather last Fall and it got extremely cold for about a week. My Thunderheads turned brown at the ends of the branches as if they had been frost bitten. They look really bad right now but the new buds (candles) are coming out. What should I do to improve their looks? Would the browned out needles eventually fall off? My pines are about three feet tall so I don't want to prune them and lose height. What do you suggest or should I just wait it out until they get all green again? Thanks for any advice you may offer. Diego


3/8/2015 at 06:16 PM by Diego Suarez

I have several Thunderhead Pines in Eastern Washington State. We had a very rapid change in weather last Fall and it got extremely cold for about a week. My Thunderheads turned brown at the ends of the branches as if they had been frost bitten. They look really bad right now but the new buds (candles) are coming out. What should I do to improve their looks? Would the browned out needles eventually fall off? My pines are about three feet tall so I don't want to prune them and lose height. What do you suggest or should I just wait it out until they get all green again? Thanks for any advice you may offer. Diego


3/9/2015 at 01:17 PM by Nick

Diego, If it is just the foliage (needles) that are brown, you are probably ok. The dramatic change in temperature probably zapped the needles leading to there brown and most likely dead appearance. If the buds on the branches that have the dead needles are elongating and are firm and not necrotic, go ahead and remove the dead needles. If you want to clean up the branches, or "lines of the tree" as I like to call them, remove needles on the bottom side of the branches. This will give the tree a more elegant and clean look. If there are any needles that are 3 plus years old, remove them. They will fall of anyways in roughly a year, so this will save you the troubles of cleaning them up later and cleans the tree up at the same time. Hope this helps!! Nick


4/26/2015 at 09:13 AM by Jan bingham

I have a 2 yr old thunderhead pine. I want to retain the shape and size. Would removing the candles accomplish this? I live in Oklahoma. The tree is healthy . The needles have turned brown. Thanks


Leave A Comment

Please answer the simple math question below to submit the form.
2 + 2 =

JOIN OUR MAILING LIST

For updates and more!

Enhancing lives by connecting people with nature to increase awareness and appreciation of our environment.

Hours

Central Daylight Time Hours:
9 a.m.-6 p.m.

Central Standard Time (Winter) Hours:
9 a.m.-4:30 p.m.

Have a question?

Admission

Adults $8.00
Seniors (62 & over) $6.50
Children (2-12) $5.00
Children (under 2) FREE
Members FREE
* Handicapped Accessible

Group Visits

Directions

Directions

We are located at:
750 Cherry Road
Memphis, TN 38117
(Between Park & Southern)

Directions & Parking