Bonsai Northwest Inc. - Yarra Valley Bonsai Society

Bonsai Northwest Inc.
Established:1973 A-19332L
Newsletter June 2015
Next meeting Monday 1 June 2015 at 7.30pm
This month we’ll be having a workshop. Just a reminder on how
workshops are conducted: if you bring along your tree, remember to
bring your own tools and wire so that you can work on your tree once
the experienced person or designated helper has given you
instructions/ideas/advice on what to do.
The Library and Sales table will be open from 7.00pm.
HOUSE KEEPING: Please note, during workshops, if you have brought in
a tree to work on, it is your responsibility to ensure all mess has been
cleaned up off the floor. Please ensure this is done as we don’t want to
lose the use of the hall.
Bjorn Bjorholm in September
If you have signed up for a workshop with Bjorn and need some advice on your
workshop material, please either bring in your stock to the club so we can
help evaluate it or email us photos of it. We want you to get the best result in
these workshops which starts with the best workshop material.
Workshops are open to everyone in the club at all levels. For the newer
members, there will be more experienced people there to give you a hand if
needed. If you need good workshop material then please let us know as we
are in the process of making available good quality stock in the coming
months. So if you really want to do a workshop with Bjorn, there is nothing
stopping you now.
Here are some photos of Bjorn’s latest work back home in Japan.
Coming Events
Bonsai Northwest Inc Spring
Exhibition
7 & 8 November 2015,
Footscray Community Arts Centre
It’s going to be great!!!
BSV Annual Sale day
Sat 30th May
9.30am to 11.30 am
East Kew Uniting Church Hall,
142 Normanby Rd., East Kew.
$2 entry fee.
‘Like us’ on Facebook
If you have a Facebook account, go to our new Facebook site and
‘Like Us’. http://www.facebook.com/bonsainorthwest
Electronic Newsletter
To receive your newsletter electronically email
[email protected]
Sponsored by:
OLOGY
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Supplying specialist potting mix
components for Bonsai growers.
Currently in stock. Mount Sylvia
Diatomite, Zeolite, 5-7mm Pine
nuggets, Pumice and Sphagnum
moss.
Our aim is to save you time and
money.
Ology.net.au - Damian 0412 698 259
Ology.net.au Damian 0412 698 259
CLUB DETAILS
www.bonsainorthwest.com.au
PO Box 1091, Niddrie Victoria 3042
Meetings are held at The Clifton Park
Bowling Club, Batman St Essendon,
7:30pm on the first Monday of the month
(no meeting in January)
President: David Nassar
Phone: Barry 0422 619 641
Find us on Facebook.
Twitter: #BonsaiNorthwest
Last Month – Multi Demo
I hope you all enjoyed the multiple demo night with
Hanh, Barry, Steve and David showing you all how there
are various different approaches, viewpoints, design
decisions and ideas when it comes to styling bonsai. All
the demo trees were auctioned off at the end of the
night and I hope the new owners are enjoying their trees.
There are a lot more photos on the club’s website.
Below are some photos from Ian’s Beginner’s class which was conducted on the 3 May. Thank you to Ian for
putting on another great class. Make sure you sign up for the next one!!!
Overpotting Bonsai
by Ian Barnes
If you’re growing trees from seed, the seedlings are generally potted into individual tubes or small
pots when they are large enough to be handled. (This is usually when the second pair of leaves
appears). After 1-3 months, tubed seedlings will be ready to transplant into larger (125 - 150 mm)
pots.
If you’re growing trees from cuttings, the struck cuttings are generally allowed to harden before
transplanting into larger (125 - 150 mm) pots.
In both cases, when good root development has occurred, the young trees will require “growing-on”
to develop thick trunks and good root spread ( nebari). The simplest and most commonly used
method of trunk thickening is to plant the tree in the ground for a number of years. Unrestricted root
growth in a large area of soil helps promote strong and vigorous top growth that in turn thickens the
trunk.
Unfortunately, for many of us in an urban environment, growing-on in the ground is not feasible.
The simple solution then is to develop the tree in a pot. Though speed of growth is reduced in
comparison to field growing, good results can still be obtained this way. However, the size of the pot
used for growing-on has a major influence on the speed at which the tree grows.
Underpotting
If the pot is too small, the tree will quickly become “root-bound.” A root-bound tree is one whose
roots have filled the pot so much that there is little or no soil for new roots to grow into. It will
survive and produce new leaves in spring but barely develop new shoots. This lack of growth will
restrict trunk development. The situation can be avoided by ensuring the plant is in a pot with
sufficient room to extend its roots. (Of course, a developed bonsai will be root-pruned so that it can
be kept in a small pot whilst still having fresh soil introduced!).
Overpotting
The fear that growth will be slowed in a small pot may lead some bonsai growers to “overpot,”
thinking that planting a young tree into as large a pot as possible will “speed growth.” Unfortunately
such “overpotting” is as detrimental to vigorous growth as underpotting. Planting a tree into a large
pot is not the same as planting into the ground!
Nurseryman Brent Walston of Evergreen Gardenworks here explains some of the reasons for regular
“potting-on” as opposed to “overpotting”. (The following explanation is taken from several posts on
the Bonsaisite Forums, http://bonsaisite.com/forums).
Let's start with the physics
“Water will drain from a pot until the lowest level of saturated soil (that can be supported) is reached.
At this point drainage stops and this saturated layer remains saturated, no more water will drain out,
ever. The height of this column of soil depends on the nature of the mix. A coarser soil will have a
lower (shallower) column or layer of saturated soil than a finer mix. The total retained amount of
water is less for a coarser soil.
“Water can be removed from this saturated layer in two ways: evaporation (the water will be wicked
upward as water evaporates from the surface), or by the absorption of water by the roots (powered
by foliage transpiration). Of these two, removal by transpiration is by far the most effective. To
prove this to yourself, just place two pots of identical soil next to each other, one with an established
plant in it, the other with no plant. Water them thoroughly and then compare the weight of the pots
over the period of one hot summer day.
“If the plant is not root established, it cannot remove very much water by transpiration. This leaves
too much water in the parts of soil without roots. In the short run, this is not much of a problem. In
a proper environment, the plant will grow and will root establish quickly so that the saturated level is
wicked dry in a day or two after a few weeks or months of growth.
“However, if the pot is so large that the saturated level cannot be removed by normal root
colonisation, problems begin. This is not dependent on the soil type. With coarse soils a larger pot
could be tolerated, but there are still limits to the space that can be quickly root colonised.
What happens if the limits are exceeded?
“If you are using an organic amendment such as bark, you will experience accelerated soil
composting. This means that you will lose your effective soil particle size more quickly than if you
used a smaller pot which is wicked dry daily. This is the most common effect. You use a pot that is
too large and it stays too wet. The organic amendment quickly decays in this wet environment,
particle size decreases, soil collapses, the saturated level increases, even more water is retained,
roots eventually remain in standing water, root failure occurs with, or without, the presence of a
pathogen. Using only stable inorganic amendments would avoid this scenario, but there are other
problems.
“Even if the above doesn't occur, what kind of root growth occurs in a volume that is not wicked dry
daily? When you water properly, a new charge of air is pulled into the pot by the volume of water
draining from the drain holes. Carbon dioxide and other gases are purged from the soil. The longer
you leave these gases in the soil, and the longer you wait to introduce a fresh charge of oxygen, the
poorer the roots will be. If you create a situation such as overpotting that doesn't require daily
watering, then you don't obtain an optimal soil growing environment.
And finally
“The best environment is a soil that dries out daily. The best potting practice is to shift to the next
larger size pot after each time the plant becomes root established as evidenced by forming an intact
root ball. UC Davis studies have shown this, and I have conducted my own studies with Acer
palmatum, which have verified it to my own satisfaction. It is not a marginal effect; the resulting
growth improvement is significant.
"The best way to achieve fastest growth is to repot just as soon as the plant produces an intact rootball. This is standard nursery practice and a well-established principle. If you do this, you don't have
to disturb the root-ball or prune the top, thus there is little or no shock and it can be done at any time
of the year. Bonsai practices somewhat complicate this, since we want specific root configurations,
but for plants in training it still holds. (An intact root-ball is when you can knock the nursery pot off
the root ball and it won't fall apart).
“Even after a plant “apparently” occupies all the soil spaces with roots, it may still grow normally for
some period of time. This is probably due to two factors that I can think of. One is that tiny hair
roots are still growing, exchanging gases, absorbing nutrients, etc. Secondly, the somewhat larger
roots are not yet “lignified,” or woody, and thus are still also fairly active.
“I think it is better to determine “root-bound” by both the symptoms of growth (or lack thereof) and
the physical density of the roots. For our purposes (bonsai), trees should be root-pruned and
repotted LONG before they reach root-bound conditions. This doesn't happen overnight. There is a
long gradual procession of slowing growth over time, usually several years before all new growth
stops. It is clearly evident what is happening if you stop to look.”
Conclusion
If developing trees in pots, regularly “pot-on” trees into successively larger and larger pots as and
when the root-ball demands it. You don’t have to find the “exact next size” pot each time; just don't
use greatly oversized containers and occasionally check that your trees in development have not
become root-bound.