Eastern white cedarBy: Vianney Leduc

Pictures: Some of the photographs are those of bonsai shown in Montreal in 2003 on the occasion of the 25th

anniversary of the Société de bonsaï et de penjing de Montréal

Common name: Eastern white cedar

Botanical name : Thuja occidentalis

The name “cedar” by itself is the name of a tree native to Africa and Asia

Basic facts

- The eastern white cedar is a coniferous tree that lives in most of the north eastern part of

North America

- It grows as far north as James Bay and as far south as North Carolina

- It can reach 15-20 metres

- It can live up to 1000 years!

- The foliage is coarse and scale-like, growing in many directions

- The bark is reddish brown in color

- Both the wood and the foliage are highly aromatic

- It is a tree that adapts easily to different types of soil (but prefers a pH between 6.5 and

7)

- The deadwood will decay extremely slowly and outlive all of us!

Cedars as bonsai

- One of the major attractions of collected cedars is their natural deadwood!

- Trees collected in nature generally have lots of character

- We can find excellent material for collecting in many areas of Ontario and Québec

- When growing under difficult climate conditions, they will often become stunted and

twisted, which make them attractive as bonsai material: in such climate, the eastern

white cedar will grow at a rate of approximately 1 cm per 15 years

- It is one of the easiest native tree to collect!

- The coarse foliage makes it more challenging to produce nice accurate foliage pads

- The young branches have a tendency to always go up; therefore, the tree needs to be

wired every year to keep its shape

- The bark can be left natural or be peeled off to display a smooth surface, where the color

contrast with deadwood is more pronounced

- The wood is soft and very easy to bend

Soil Watering- 1 part coarse gravel - loves humidity

- 1 part organic matter - do not allow soil to dry between waterings

- 1 part porous rock - water twice a day on hot summer days

- should be well drained - loves misting of foliage

Sun exposure Fertilizer- needs full sun for best results - needs acidic fertilizer for coniferous trees

- half shade = poor foliage result - 30-10-10 at half strength, once a week

Repotting Jin and Shari- strong root growers once established - ideal tree for jin and shari

- repot every second or third year - the deadwood does not rot

- remove about 50% of the root - occurs naturally on collected specimen

- best time= end of April to end of May

- can also be repotted in early September

Wintering• very winter hardy and can be placed outside for the winter as long as it is protected

from the sun and the wind

• sun and wind can dry weak foliage resulting in winter kill

• if wintered outside, it is important to thoroughly water the soil before putting the pot

in the ground

• they may also be wintered in a cold room ( -5 to +5) but do not let the soil dry out

Collecting• the eastern white cedar is one of the easiest native tree to collect since it tends to

develop a dense root system (you need to excavate less to get a viable root system)

• they tend to survive with few collected roots if placed in the shade and misted often

• it is very important to give extra winter protection to newly collected trees, they can

easily dry out in the winter (best to keep in cold room if possible)

• it is best to collect them in the spring but they can also be collected in late summer

Branch pruning and wiring• it is better to jin a front branch you want to remove since eastern white cedar will not

grow over pruning scar

• younger branches are easy to bend

• old branches on collected specimen are brittle and require raffia to bend

• the branches can grow quickly around the wire if left unchecked and therefore require

frequent rewiring during a growing season

• preferable to wire a tree in late August and leave the wiring until early spring

• young branches will always pull up and need constant wiring

Insects• is not prone to insect attack: mini red spider can affect the tree

• a preventive measure is to regularly hard spray the foliage

• use 1 tablespoon of dishwasher soap per litre of water if red spider are not under

control

• some insects might use the deadwood as their home: use lime sulfur

Foliage• branches with neatly-layered pads are harder to achieve due to the coarse foliage

• can build neatly-arranged foliage with lots of detail wiring or opt for large foliage pads

• prune the foliage again after 2-3 cm of growth to achieve dense foliage

• weekly application of fertilizer will provide lush green foliage and lots of growth

• on collected specimen, it is sometimes necessary to combine the foliage of two or

more branches to create the illusion of one large foliage pad

• the foliage has a top side, it is important to wire branches without inverting the foliage

or they will die

• there is a natural shedding process on eastern white cedar where some of the foliage

will turn orange and die in the fall

• it is possible to graft (approach grafting) finer foliage from Chamaecyparis (false

cypress)

• the foliage will turn to an olive type color in the fall

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Redesign project for a collected cedar

Collected in August 97 First design in 99 Show 2004

- The design was very classical and very balanced with equal amounts of foliage on each

side of the trunk

- I used the whole tree for the design ( a common mistake…!) rather then concentrate the

design around the main feature of the tree

- Two lines of shari were created on the trunk

- The foliage pads were large and created mostly by pinching, with minimal wiring

- I used the tree in the Andolfo School of Bonsai for a redesign exercise

- Andolfo always focusses on optimizing the quality of the tree when choosing a design

- He felt that the top part of the tree was boring and concentrated his design around the

lower part

The new design :

- The tree has a direction

- The triangular shape is now very asymmetrical

- There is a lot less negative space between the foliage pads

- The design is more dynamic

Preparation of the foliage for detailed wiring

Peeling of the rough bark to get a smooth surface

Increasing the area of the shari