Potentilla fruticosa `Koboltī
Simple garden nursery material often makes
good shohin-bonsai if a decent trunk is present and the specimen tolerates
some fair pruning. Potentilla fruticosa, now also becoming increasingly
popular in Japan, is a very suitable and easy grown specimen for small bonsai
having the advantage of tolerating major pruning.
Raw stocks from an ordinary garden nursery
is a way to acquire a material with all the benefits and disadvantages that it
Benefits first: The material is already grown for some time, it is in a pot with
limited root space and therefore easier to adapt to a smaller pot at a later
time than field grown material may do, the size for Shohin and Mame are obviously a
great advantage, and finally there are great possibilities to buy something for
continued controlled growing for future styling. And it is much cheaper than
buying a prepared bonsai.
Disadvantages: It may be difficult to find a unique shaped tree, and there can
be many too uninteresting trees around making it difficult to find a tree;
because these trees are not aimed at bonsai purposes and mass produced with dull
characteristics like thin straight speed grown trunks.
Looking for any kind of bonsai raw material the focus must be on finding a good
trunk with movement and some tapering, or future possible tapering by pruning.
Look for the trunk especially, and for some time forget about foliage and
branches on specimens were new ones will easily grow after hard pruning.
(Conifers e.g. does not tolerate pruning below foliage).
In this example the very tall Potentilla has an interesting trunk, and because
this specimen tolerates very hard pruning this is the only thing to concern
about searching for qualities.
First year the tree was reduced heavily by simply cutting the branches off at
the base of the trunk.
One year later, early spring.
The first task in spring was to repot the
tree adapting it to a smaller pot. Because of the reduced foliage mass and a
compact fine feathered root ball it was possible to do it in one go. Normally I
reduce the root ball over several seasons depending on the specimen. The
Potentilla is very rapid growing and therefore it tolerates this treatment if
followed by a good feeding programme afterwards (always take in consideration
how well the rootball is developed, if not to make failures with this kind of
dramatic reduction of root mass).
A few thin branches was kept to speed up growth.
No intended styling yet, only focusing on
reducing the size.
New branches grown well the past two years,
and flowers emerge on same years growth. These are removed though to produce
leaves and branches instead of flowers that will delay development.
Late summer. Part of the trunk has been styled as deadwood (Shari) because the
scars doesn't heal like many other deciduous specimens, leaving just a flat cut
looking very artificial. Therefore these larger cuts must be hidden on the backside
and/or turned into deadwood features.
contrast between the romantic feminine flowers and deadwood is stunning and
Late summer. New growth has been trimmed and
slightly directed with wires. Be aware with Potentilla, that only younger
branches tolerates wiring and careful bending. The older they get, the easier
they snap when bending is tried, and a branch broken is lost. Branches
heal badly, so be careful training only young branches by wiring and with great with care.
The rest is controlled through pruning exercises.
Please note that the front is changed and a now smaller suitable pot is found. The pot
underlines the elegant slanting style, and the green coloured pot suits an
summer image very fine. It may be changed for an winter exhibition when branches
stands naked, but depends on the overall display style and feeling wanted.
The colour of flower and pot goes nicely together.
live vein running along the deadwood trunk shows a great contrast between live
and dead. As with Junipers the bark is loosening slightly at the trunk in larger
flakes, that distorts the proportions. Therefore I brush them of gently to
enhance the contrast between the rough deadwood and the fine live vein, making
contrast bigger and more beautiful.
The tree has now developed very well and
reached its high point of the summer season, showing great flowering. Not too
many flowers appear at once, so I don't need to reduce flower buds in order to
keep a modest and elegant image. In the west, and sometimes seen at Japanese
Satsuki Azalea shows, too many flowers overwhelms the image, and the tree itself is lost
To make the Potentilla fruticosa `Koboltī flower, you need to let
it grow almost uncontrolled (no pruning) from midd spring. Controlled back pruning of
branches in earlier spring is necessary, afterwards leaving branches grow
unattended. When flower buds appear in summer, very long branches can be pruned
away keeping the shorter flowering branches.
Letting a few long branches growing keeps other branches shorter, taking away
energy from the growth of other branches. Later these overgrown branches are
removed after forefilling their task.
image of the tree. Note the long thin branches earlier bearing flowers from
summer throughout autumn.
Note also that other
flowering Potentillas may flower at other times of the year, and therefore the
pre coordinated back pruning of branches have to be carried out accordingly.