Larches as bonsai - The Ottawa Bonsai Society

Larches
November 2012 V1.0
Vianney Leduc
Common name: American larch, European larch, Japanese larch
Botanical name: Larix laricina, Larix decidua, Larix kaempferi
Larches as bonsai
- It is the only coniferous tree that will lose their foliage in the winter
- It is a tree that can be appreciated in every season
- Will enjoy the structure in the winter
- Will have tender light green buds growing in the spring
- Will show dark green needle in the summer
- Foliage will turn a nice yellow in the fall
- Even if it is a coniferous, it has some characteristics of deciduous
- It reacts well to strong pruning
- Can cut large amount of roots during repot
- It does not tolerate shade
- Very winter hardy
- Can thicken up quite fast if first develop in the ground or in very large wooden boxes
- They will develop nice rough bark that can vary in color between dark brown and grey
- It is a tree that adapts easily to different type of soil (but prefer PH between 5 and 6)
- The deadwood will not decay fast on collected material
- Decent ability to bud back (will not bud back on old wood)
- Trees collected in nature offers a lot of character
- We have areas in Ontario and Quebec that have offers excellent material for collecting
- It is relatively easy to collect (but success rate around 60% for old trees)
- The wood is very soft and very easy to bend in the spring (less so in the fall)
Larch in fall color
Soil
Watering
- 1 part coarse gravel
- 1 part organic matter
- 1 part porous rock
- Should be well drained
- Can take daily watering
- do not allow soil to dry between watering
Sun exposure
Fertilizer
- Need full sun
- need acidic fertilizer for coniferous trees
- 30-10-10 half strength, once a week
Insect
- No predator in my experience
Repotting
Jin and Shari
- Strong root growers once established - ideal tree for Jin and Shari
- Repot every third year
- the deadwood does not rot on collected trees
- Remove about 50% of the root
- occurs naturally on collected specimen
- Best time= April when buds open
- Can also be repotted in late September
Wintering
very winter hardy and can be placed outside on the ground for the winter
they may also be wintered in a cold room ( -5 to +5) but do not let the soil dry out
The larches can growth quite fast in the ground
This tree was the size of a pen 10 years ago when planted in the ground
Foliage growing patterns
Need to understand the growth pattern in order to make the proper action(s) suitable to
the development stage of each branches
Foliage is growing in every possible direction but is easy to train
Bud can develop into a 5” of new growth in one growing season under
ideal condition
The buds can clearly be seen on a new section after the needles have fallen.
Foliage pad refinement
can build neatly arrange foliage with detailed wiring
perform detailed wiring only when foliage is gone
o on mature tree this should be done on tertiary and smaller branches only
is key to have good ramification to achieve fuller foliage pads
remove new growth of foliage growing under a branch
remove portion of needles growing under the branch when showing tree
some books mention that thread and approach grafting is feasible (in case of an old
branch with foliage too far from trunk)
the foliage will turn yellow color in the fall
o if it turn brown during summer = pot is too hot
pinch second growth in late spring
o to encourage back budding
o to maintain foliage pads profile
controlling needle length on American larch
o The length of the needles on the American variety tend to be long
o The Japanese variety has small needle
o One method use by some is to control the watering in the spring
o Other method consists of plucking the needles in midsummer to encourage a new
growth. Should be done no later than end of June.
Branch pruning and wiring
branch pruning can be done at any time during the growing season
the wood of the larch is one the easiest to bend when done in the spring and growing
season (it does get stiffer after the needle turn yellow
severe bending of branches should be done in spring only
do not apply wires too tight on main branches given that they can growth quite a bit in
a season
larger branches (more than 3/4”) should be protected with raffia to bend
there are mention in some books that wiring and bending in late fall will lead to losing
branches
Branch development
to achieve desired thickness and ramification
use strong feeding program during that development
the branch is now in a stage where foliage refinement needs to take place
need to encourage the buds development close to the trunk
pinching of second growth is now required
Collecting
the American larch relatively easy to collect in normal condition
o it is best to collect them in the spring when the buds are waking up
o can also be collected in fall when needles are yellow
old stunted tree living in harsh environment is more challenging to collect
o needs to be collected in the fall when needles are yellow
o need to be kept in semi shade in the first year
o will know if the tree survive only in second year
o can be found
 on lake shore (e.g. Georgian bay area)
 in bogs environment (e.g. north shore of St-Lawrence)
 on small hills close to bog area (e.g. north shore of St-Lawrence)
o some area like the bogs offer a very acidic environment (i.e. ph around 4, 5)
o when coming from such acidic soil
 collect as much of the soil as possible
 do not remove the original soil when potting
 make small insertion with chopstick and insert coniferous soil in
 this will help roots adapt to less acidic soil
Example of bog area
Walking conditions are strenuous most of the time!
Project of collected larch #1
Collected in fall 2006
First design in 2011
Notice the original soil. First repot was in 2010
Fall 2012
Notice that the new growth is pointing upward.
Fall 2012 after reducing foliage and wiring
Project of collected larch #2
Collected in fall 2006
Reducing length
Target design
The focal point will be well exposed and is a key part of the design.
Collected larches offer enormous potential for deadwood
The movement of wood fiber is quite interesting and will enhance the value
of the focal point
Project of a nursery tree
The first part of the work consisted in removing the bark in the central area
Target design