Thickening Your Bonsai Branches: 3 Simple Ways to Build Size

  • By: Josh Koop
  • Date: August 24, 2021
  • Time to read: 6 min.
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Growing a Bonsai is a meticulous art. People who have just started to grow Bonsai face a lot of issues regarding its growth. Especially when it comes to thickening the branches. So, a lot of Bonsai enthusiasts are often curious to know – how to thicken Bonsai branches?

The branches of a bonsai tree can be thickened by growing sacrificial branches. Also, experts advise to grow the bonsai tree in the ground first and then transfer it into a pot. Scarring is another technique that is used to thicken the structures of a bonsai tree.

Nevertheless, not all Bonsai plants grow at the same rate. It varies with the environmental conditions, weather changes, temperatures, ensuring proper feeding to your plants and many other factors.

I highly recommend you to read the entire article for a better understanding.

3 Simple Ways to Build Branch Size

A Bonsai tree requires years and years of tender care to grow into the desired size. As a beginner, there is so much to learn about the art of growing Bonsai.

You must be very patient as it takes a long-time span, sometimes more than a decade. The horticulturists have developed many ways to thicken Bonsai branches. But these 3 have proven to be the simplest techniques:

Growing a Sacrificial branch/leader

This is the easiest method but it takes many years. In this method, you allow a specific branch of the tree to grow for many years without pruning or cutting it off. Then after the desired growth is achieved, you have to cut it off or in other words, sacrifice it.

When you allow the branch to grow unchecked, it creates a blockage at its point of growth. In this way more nutrients, more growth factors are expended on this branch to support its growth for a long period. The branch grows longer and thicker taking up more nutrients.

All this happens due to Apical Dominance. The apical bud cells have the highest potential to divide and tend to grow more. So, this potential is distributed into the branches with the growth of the sacrificial branch.

It is better to grow the sacrificial branch at the top of the tree. Because as it takes up the highest nutrients, the portion of the tree above the sacrificial branch doesn’t thicken anymore.

So, when you grow it at the top, it will cause the growth of the entire tree – branches, roots, shoots, leaves, trunk and everything.

It usually takes 1-5 years to achieve the desired growth. But it entirely depends on the species you chose and the environmental conditions.

Grow your Bonsai in the ground first

A Bonsai tree is like the miniature version of any other normal tree. The word Bonsai means, “Planting on a tray”; it simply indicates growing a tree in a tray/pot in order to restrict its size.

If the same plant is grown in the ground, it will rather grow into a big tree. This concept is used in this method.

When you grow in the ground the tree can have all the essential growth nutrients that enable it to grow faster into a larger tree.

But you can’t provide all these growth factors in the limited area of a pot. That’s what causes the tree to be a miniature and gives the desired aesthetic look.

In order to get thicker branches, before planting it into a pot, plant it in the ground for a short period. This will allow the Bonsai branches to get all the nutrients required and thicken in size.

When you reach your desired thickness and build, transfer it to a small pot as per your needs.

You can now restrict the growth as per your requirements by transferring the tree into the pot. And now you have a Bonsai with thicker branches.

This is a slow process as you have to wait for the Bonsai to grow. For quicker results, choose the fastest growing species like Chinese Elm or Ficus. Junipers tend to grow very slowly.

Scarring method

This technique is more useful to increase the bulk of your trunk rather than the branches. But this can be practiced to thicken branches too. It is very simple and easy to perform.

Scraping a part or injuring the skin of the branch causes a scar to form. When it heals there is a swollen callus around the wound.

So many swollen calluses gradually cause the branches to thicken. It takes about 2 to 5 years for a wound to heal. May take a decade to achieve the desired thickness.

Factors that Influence Branch Thickening

Like any other plant, a Bonsai needs the optimal environment to grow. There are various factors that come into play when it comes to the branch size.

Keeping them in mind can also be important in maintaining the proper growth on your bonsai tree. These factors include:

  • Enriched soil
  • Sufficient sunlight
  • All the macronutrients required for growth
  • Micronutrients
  • Proper feeding and water supply
  • Proper aeration
  • An ambient weather
  • Fertilizer/Compost
  • Wiring and tapering at correct angles
  • Choosing the right sacrificial branch
  • Choosing the right pot
  • Pruning at regular intervals

By ensuring these you can expect your bonsai to grow healthy and strong. So, try to ensure these first to ensure the optimal branch thickness.

Remember, no matter what techniques you follow if you do not ensure proper nutrition and environment your bonsai will not grow properly. So, ensure these first and then move on to more advanced methods. 

What Makes the Bonsai Branches Thinner?

The Bonsai is an aesthetic plant. Care of a Bonsai is no less than a sculpture. To retain its beauty, you must ensure all the favorable circumstances for your Bonsai tree. Otherwise, it may lose its aesthetic beauty.

The beauty of Bonsai is in its shape, pattern, uniform distribution and size. The trunk and the branches are the support to the leaves and the growing buds.

Under favorable circumstances, the trunk and branches can become durable enough to support the growth. It’s important to maintain this environment for the Bonsai for as long as it lives.

So, it’s quite understandable that some unfavourable conditions can cause the branches to become thin and spindly. A few are mentioned in brief below:

  • Unhealthy roots and shoots: If your Bonsai tree is deprived of sufficient sunlight, water, air, all the essential nutrients and good soil – the roots and shoots can become lean and thin. This causes the future branches to become as thin as sticks.
  • Bad soil: The soil is its main source of nutrition. Choosing poor soil can hamper branch growth.
  • Improper watering: Poor or even excess water supply can hinder the growth of bonsai too.
  • Insufficient aeration: Grow your tree in an open area with adequate air flow.
  • Improper drainage: Drainage block can affect your roots and ultimately, the branches.
  • Avoiding pruning: You must prune your Bonsai at regular intervals. To give an aesthetic look, make the shape look like a triangle with unequal sides.
  • Wiring and bending: Bending at bad angles, too tight or uneven wiring hamper future growth of branches.
  • Choosing a lower branch as the sacrificial branch: This point is so crucial for your Bonsai branches. If you choose a branch at the bottom of the tree as your sacrificial branch, as a general rule, the part above the sacrificial branch doesn’t grow at all. So only the part below it will have thicker branches and the rest of the tree will remain thin and spindly.

Final Thoughts on How to Thicken Bonsai Branches

A lot of work on thickening branches on your bonsai will be down to quality management of the work you do, not cutting fast and furious and having a high level plan.

Plan out sacrificial branches ahead of time and have a understanding of where you are going to make sure you prune in order to achieve this goal, anything less than focus can lead to poorer results.

If you are just learning about bonsai trees and looking to purchase high quality trees that will likely live longer than you then I would highly suggest checking out Bonsai Boy Trees as they are a long lasting New York business that provides trees for all price ranges!

Here are some of my favorite Bonsai Items

Thanks for reading this article, I have a few items I love to use with my bonsai tree care and wanted to share the best options for the core needs for the new bonsai enthusiast!

Best Bonsai For a Beginner – Most of what you find online are starter plants where they are going to be difficult to start and grow successfully. Most beginners like to have a starter plant to work from. I highly suggest looking at Bonsai Boy directly (more options and good prices), or you can look at their inventory from Amazon.

Best Bonsai Tool SetTianBonsai makes the best quality tools for simple bonsai work, if you want tools that will last you they won’t come cheap, make the right investment the first time with these beginner tools on Amazon!

Best Bonsai PotBonsai Boy’s Beige Ceramic Bonsai Pot – The team at Bonsai Boy operates out of New York and has been perfecting bonsai in the US for over 50 years, there is a reason I love and share them, if you want to order directly from Bonsai Boy then click here, or click here to order through Amazon.