Selecting a container for bonsai is of paramount importance as it adds to the beauty the tree presents to the viewer. Also, by definition, a bonsai must be potted. There are many factors in determining the correct container including the following aspects.
Purpose: If the tree is undeveloped, it is best to train in a round deep pot. The depth will help the tree grow vigorously, while shallow pots, which are normally used for training bonsai will develop a more compact root system, but the tree will grow better in a round deep pot. Roots have an easier time to follow the curved interior of a round pot when growing, while roots in rectangular training pots or wooden boxes must make a 90 degree turn and grow slower.
Therefore, trees which are being trained or encouraged to grow are usually planted in larger, rather than smaller pots. While developed bonsai are potted, usually in ceramic exhibition containers.
Size: An appropriate size container must be selected for beauty, balance and the horticultural growth of the tree. Many flowering and fruiting species prefer to be grown in deeper containers to support the flowers and fruit. While evergreens can withstand drying out, shallow containers are commonly used.
Also, the climate must be considered. Often bonsai grown in tropical or hot areas are planted in deep containers, so the roots do not dry out. Bonsai are often planted in deep containers which hold more heat during the winter to protect the trees in cold and frigid climates.
There are many different formulas to determine the specific size of a bonsai container. The method I use for standing style bonsai is the height of the tree should equal the length and depth of the container. This is determined by visual mass. A 12 inch tree could be planted in a pot 10 inches long and 2 inches deep. The same 12 inch tree would also look and be balanced in a pot 8 inches long and 4 inches deep. In general bonsai appear to be larger in smaller sized containers.
Species can also determine the size of containers. Fast growing bonsai such as Weeping willow or Crape myrtle are best grown in larger, deeper containers. Of course, heavier trunks should be planted in deeper containers for visual balance and thin delicate trunks look great in shallow pots. Also, the original root formation of collected native species sometimes determine the size and shape of the pot, until a compact root system is trained. This is also the case for nursery or field grown trees until smaller root systems are developed.
Shape: There are many different shaped containers, but basically, they all fall in one of the following two categories, equal sided and unequaled shapes. Examples of unequaled sided containers are rectangular and oval. Equal sided containers include round, square, hexagonal and multi sided.
Generally standing style bonsai are grown in unequal sided containers when the width or branches are to be emphasized. While equal sided containers tend to enhance tall trees, such as literati style because the eye movement will travel upward faster. Equal sided are also usually used for the cascade styles only deeper for visual stability.
Color: Color selection is mostly determined by personal taste and understanding of bonsai. Some like to harmonize or compliment the main color of the tree and container, like a red azalea in a red pot. Others like to use contrasting colors, like a white Flowering crabapple in a blue, green or colorful glazed pot. Of course, unglazed brown, red, grey and tan colors are quiet and are usually used for evergreen species, so they do not detract from the beauty of the bonsai. Almost any species look good in brown unglazed containers, but they are so commonly used that they can seem boring.
It is also important to consider what time of the season you intend to enjoy your bonsai. A bright yellow container might make a great contrast with colorful maples in autumn, while after leaf drop the yellow would be overwhelming. Many who grow small and shohin bonsai often have several pots which are seasonally used. I have ten different colored and shaped containers for one maple bonsai. They are changed according to the season of enjoyment or how they are used in box display tables to avoid duplication.
Design: The container rim, side body and feet all play an important part in selecting the right pot for your tree. Outer rimmed containers usually look good for deciduous and flowering and fruiting species. While straight rimmed pots are often used with pines and other evergreen when a simple feeling is preferred.
The side bodies can be straight or angled or curved. Straight sided containers are often used for bonsai with straight trunks where a more formal appearance is desired. Oval containers are the most versatile shape, especially one with curved sides. Additionally, painted pots with designs are often used in smaller size bonsai where the color and design would not be overwhelming.
Quality: One important factor for selecting containers for bonsai, which is often not considered is the quality. I have often seen beautifully shaped bonsai in inexpensive bonsai pots. I have, as well, seen undeveloped trees in training gown in old antique containers. Most bonsai hobbyists do not consider the quality, but as they gain more experience and exposure to higher quality pots, they begin to understand that container quality is important to release the full beauty of a bonsai for appreciation, yours and to the viewers.
Selecting A Container for a Dwarf Scots pine
For several months I’ve been on search for the “perfect” container for one of my Dwarf Scots pine. This last week we narrowed the selection to two unglazed grey pots. Then, as we were potting, suddenly three more unglazed brown pots were considered. I would have preferred a brown pot because the needles of this Dwarf Sots pine are bluish and would sharply contrast with the brown pot. I tried to avoid the two final unglazed grey containers which are kind of similar to the foliage. Of the three new pots to pick from, one was too plain, one was too large and one not of high value or quality.
Watereri Scots Pine
Pinus sylvestris ‘Watereri’ generally develops into an upright pyramidal bush or small tree, often used in rock gardens. However, the original tree, selected in 1865 is still alive and now reaches about 24 feet in England. They rarely grow that fast in smaller sizes. This cultivar must be asexually propagated by grafts, budded or air layered. I have not seen this cultivar root. Some of the original tissue must be maintained. While some have produced seedlings, they are not identical to the original Waterei Scots pine. The graft union is very good for my tree. When and if the different bark colors bother me, I’ll glue additional reddish orange at the bottom.
A good graft union
Side A deep container Side A shallow container
In small sizes, the Waterei Scots pines are usually container grown and develop into nice compact shapes, perfect for bonsai training. They can be commonly found in rare plant nurseries and garden centers. The needles are quite short naturally with a bluish green coloring. Using the correct bonsai training techniques, they can be maintained to about one or two inches in length. The orange buds are attractive in spring as they open as is the reddish orange peeling bark, which is also characteristic of the common Scots pine.
Side B deep container Side B shallow container
Once the final container was chosen the tree needed to be lifted from the small brown bonsai container it was grown in for about 15 years from a container grown grafted plant. The reddish orange bark is paper thin and fragile as well as attractive. There are two methods to handling trunks with fragile or colorful bark. First the tree can be lifted from lower branches, avoiding touching the trunk. Another method often used is to carefully wrap the upper bark with moist newspapers or paper towels and to only handle the paper, not the trunk. I have seen many valuable and old bonsai, especially with Cork bark Chinese elm, ruined by not protecting the bark when moving and repotting.
Lifting tree from branches to protect bark Lifting tree using moist paper towel to protect bark
Yesterday I posted two photos of my Dwarf Scots pine on Facebook and invited readers to select their choice of containers. Many comments were posted, and the vast majority preferred the deeper pot. Me too!
The deeper container was selected because of the size, rim shape, feet, quality and sides. The shallow container seemed a bit small for the tree, but when root pruned the tree fit in perfectly. Using my formula for determining the pot size for standing style bonsai, the tree is 24 inches tall, the length 16 inches while the depth is 4 inches. The dimensions, 16 inches plus 4 inches is 20 inches, which is about the ideal size. I know in two or three years, should I still own this bonsai, the twigging will increase and present a full massive canopy which will fit the straight sided deep container.
The outer lip and bottom belt on the shallow pot were a bit too busy for my taste. Usually, I like to use rectangular pots for evergreens, especially pines because they are the most formal and powerful of all species.
The deeper container presented a more stable feeling for this bonsai. The plain undecorated sides really contrast with the reddish orange bark. Although I prefer rectangular containers with no rims. The gentle corners picked up the feeling of the character branch on the right side. The shallow pot had a stepped foot, while the deeper pot had a flat foot, thus adding more stability and dignity for this pine bonsai. The shallow pot was a bit too elegant for my taste for this bonsai massive bonsai.
It is interesting to note that I purchased this Japanese Tokoname-ware container from Saburo Kato when I was an apprentice in Omiya Bonsai Village, Japan 50 years ago. I believe the container artist is Seizan, who was the father of Reiho. Fifty years ago, I easily hand carried the container home from Japan. Today, I could not even lift the empty pot.
After carefully trimming and arranging the roots the tree was positioned in the container. My preference is just off center with one edge of the trunk touching the center line. This unusual bonsai can be appreciated from both sides. Rather than plant the tree with the top leaning slightly forward we positioned the tree straight up so the tree would look good on both sides. Having two front viewing sides is an important factor for my bonsai design because I like to share my trees through display. Sometimes the trunk movement is in the wrong direction for the display area, or the scroll painting is in the opposite direction. With having two pleasing fronts the tree can be displayed in both trunk movement directions.
Also, one basic factor in selecting the viewing side was the shape of the trunk. All trees do NOT grow in an even shaped circle. Many are oval, making the trunk appear narrower from one side. We selected the viewing side which showed a more tapering trunk.
Removing ugly stump A large curved knob cutter was used twice
A sharp chisel used to shape cut Brown cut paste was pressed into the deep wound
However, one determining factor to select “a” preferred viewing side was the unusual first branch on the right with unique curves. This focal point, or character branch, had an ugly stump hiding the beauty of the entire length of the branch. We took a large, curved knob cutter and first removed most of the stump. It was old, dried out and hard. Although a large size tool could have easily removed the stump, it was taken off in two steps to make an exacting smooth cut. The second cut made a slightly concave cut. Then a sharp chisel was used to make the cut deeper. Brown cut paste, usually used for evergreens was packed into the wound and pressed hard. Finally, small pieces of the reddish orange fragile bark were carefully placed on the cut paste and pressed to maintain contact. One would never know an ugly stump was there an hour earlier. The tree was mossed, photographed and finally watered.
Narrow trunk base Heavier trunk base with taper
I hope some people will find these thoughts helpful with their bonsai creation and container selection. Have fun transplanting. Spring has finally arrived in Upstate New York, and we are praying it stays.
Side A, another viewing side
Trunk positioned straight up so both sides can be appreciated