Plant Care

Bonsai requires such a small amount of soil that I would advise the use of high quality imported Japanese soils such as Akadama, Kiryu and Kanuma for Bonsai growing. Your soil mixture will vary from region to region depending on winter and summer temperatures, as well as the amount of precipitation in your area. Excessive rainfall can be avoided by a greenhouse or other structure and will allow your soil to slightly dry between watering, and will also prevent accelerated breakdown of your soil. Your soil particle size is determined by the size of pot you intend to use and the size of the bonsai tree. As an example, Shohin size trees will require 1/32"-1/8" soil size and medium Kifu Sho size trees will need 1/4"-3/8" soil size. It’s also very important to sift and remove all fines from your soil and flush the potted bonsai until clear water is seen running out of the bottom of your pot. Here are some commonly used Japanese soil ratios:

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Japanese Maples (Acer palmatum) and  (Acer Buergerianum) :           

Japanese Beautyberry  (Callicarpa Japonica)                                            50% Akadama 30% Kanuma 20% Kiryu

​Japanese Wisteria (Wisteria Floribunda)

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Japanese Flowering Apricot (Prunus Mume) :                                          80% Akadama 20% Kiryu

Japanese Flowering Quince (Chaenomeles Japonica) :

Satsuki Azalea (Rhododendron Indicum) :                                                 100% Kanuma 

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Japanese Black Pine (Pinus Thunbergii) 

Japanese Red Pine (Pinus Densiflora)  :                                                     1-1-1 Akadama, Pumice, Lava

Japanese White Pine (Pinus Parviflora) 

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Shimpaku Juniper (Juniperus Chinensis) :                                                  3-1-1 Akadama, Pumice, Lava

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​Akadama (Red Ball Earth)

 This is a naturally occurring, granular clay-like mineral used as soil for bonsai trees and other container-grown plants. It has exceptional porosity and drains well. One significant drawback of Akadama soil is that it breaks down into smaller particles in cold or wet climates.

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Kanuma

 This is a granular clay-like mineral used mainly as soil for bonsai trees. It is weathered volcanic pumice stone, which can be defined as a mixture of minerals and organic materials. Kanuma soil is great for acid loving species such as Azaleas, due to good water retention, drainage, and aeration. This soil also breaks down into smaller particles in cold or wet climates.

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Kiryu

 This is granular-shaped volcanic sand with excellent drainage and aeration.  It is especially suited for coniferous trees, which prefer a drier environment for healthy root growth. Unlike some other common bonsai soils like Akadama and Kanuma that may compact over time, Kiryu soil maintains its structure and porosity for a long time. This prevents the soil from becoming overly dense, which can impede drainage and root growth.

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Hyuga

 This is a light weight volcanic soil that's ideal for its moisture retention and water drainage properties. Its very porous pebbles have similar physical characteristics as pumice. The minerals inside it help lower the pH levels and aid in the exchange of harmful gases to help prevent root rot for your bonsai tree. It's best used by mixing it with other soils such as Akadama.

Organic Versus Inorganic:

The major elements needed for plant nutrition are N, P, and K. The source doesn't matter to the plant.

A slow-release fertilizer such as Osmocote or Nutricote in spring or early summer is very beneficial. Follow the application rates stated by the manufacturer.

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If you would like to use organic, slow-release fertilizers like Green King and Biogold are very popular proven Japanese fertilizers. The recommended application of Biogold is 5 pieces for every 5 inch pot. Green Kings recommended rate is 3-5 grams for a 6 inch pot, 10-15 grams for a 12 inch pot. These fertilizers also release micro nutrients.

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It is always tempting to give your new plant lots of fertilizer, but with Japanese Maples and some dwarf varieties, less is more. It would be better not to fertilize at all than to over-fertilize. It's also important to remember that variegated type Japanese Maples can temporarily or permanently lose their variegation when given too much fertilizer. This is called "reversion." Some varieties are more prone to reversion than others.

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Micro Nutrients:

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 Chelated micro nutrients are a great water soluble supplement to prevent or treat mineral deficiencies in plants grown in artificial soilless media. Follow the recommended application rate stated by the manufacturer. Another option is adding organic fertilizer in the form of animal and marine byproducts. This helps supply these minerals. Many of these elements are also present in ordinary tap water. Check your local city water quality analysis for mineral levels.

Winter can be a great time to ship certain varieties of plants because they are dormant and not easily stressed from the shipping process. It is important to protect your potted plants from temperatures below -1 degree Celsius. Storing the plant in an un-heated garage or shed is the best option. Do not be tempted to store your outdoor potted plants indoors. They need to stay cold and dormant for the winter months, which is very important for plant health.

Although most ornamental plants have a wonderful natural branch structure, pruning is a great way to form and train your tree to fit your bonsai vision or the look you want in the landscape. If you are growing for bonsai, don’t worry about branches until the trunk is formed. Then you must form a branch before you can ramify it. Every species of plant responds differently to different pruning techniques. Online courses and books on the specific species you're growing will help you learn appropriate pruning techniques. ​

Some varieties of ornamental plants such as Japanese Maples are grafted onto an understock or rootstock. It is important to know where the graft union is on your tree and promptly remove any new growth below the graft union. Although a fresh green shoot growing below the graft union may look harmless, some rootstock are extremely vigorous and eventually take over the tree.