re-potting Callistemon ‘waterswept’

December is summer in Australia so here at Shibui Bonsai it is time to re-pot some of my native bonsai and potensai.

I started the day with my Callistemon ‘ waterswept’ bonsai. This one was slip potted into the current pot a few years ago but has not had a proper re-pot for quite a few years. It has finished flowering so it was time to stop procrastinating and get on with it.

before

 

Here is the tree before. The design is based on trees that grow in the bed of the nearby Ovens river with roots clambering over the rocks in midstream and all the growth battered downstream by frequent floods.

 

 

 

 

spent flowers

 

This one only produced a few flowers at the top of the tree this year. All the flowers have finished so it is a good time to re-pot.

rootball

after re-potting

After root pruning it was re-potted back into the same pot.
Potting mix is my standard mix with standard osmocote added.
I forgot to take a picture of the rootball after root pruning but the pile of old mix and roots I cut off will give you an idea how much the root ball has been reduced.

after pruning

After potting the tree back into its pot it has been given a final trim to remove the old flowers and any excess branches.
To get flowers next summer I must now leave the new shoots to grow and mature because Callistemon flower only on the shoots that grew the previous season.
Finally the tree is given a good soak in water then put back on its stand which is in full sun most of the day.

 

banksia proteoid roots

Summer is also time for repotting many of our Australian native plants. I was repotting some banksias and came across this interesting phenomenon.

We hear so much about Australian Native plants being allergic to phosphorus and needing very careful fertilising. the truth, however, is that only a very few Aussie natives are sensitive to phosphorus and there are also a few plants from other parts of te world that are phosphate intolerant as well. I give most of my Australian natives the same fertiliser that I use on the exotics and they grow very well on it.

The exception is Banksias and here is the reason

proteoid roots on banksia

That white patch that looks like fungus is actually a patch of specialised roots called proteoid roots that have evolved in some of the proteacea plants to help them extract phosphorus from the nutrient poor soils they tend to live in.

a closer look

 

 

Looking a bit closer you can actually see the hundreds of tiny white root tips that are all collecting every available scrap of phosphate from the soil.
And that is the problem. When we apply phosphate rich fertiliser these tiny, super efficient phosphate absorbers continue to grab all the available phosphate. That results in a phosphate overdose and  a very quick death for your banksia so be quite wary of what sort of fertiliser you give to your banksias.
Banksias do not NEED proteoid roots and when they are in an environment that has adequate phosphate in the soil they do not develop these special roots. If we slowly incease the amount of phosphorus in the soil the tree will gradually shed any proteoid roots and can then tolerate normal amounts of phosphate fertiliser but as soon as the nutrient levels drop off again the plant will again grow more proteoid roots and will be sensitive again.
When repotting banksia bonsai most of the proteiod clusters are cut off but that will not hurt the tree any more than normal root pruning hurts any other species.
I do not want to give the idea that banksias can grow without any fertiliser. When grown in a pot nutrients are quickly leached out of the potting mix by regular watering so even banksias need regular fertiliser but its best to play it safe and use a low P formulation.
Many of our banksia species make excellent bonsai. They will shoot on old wood when pruned, They tolerate root pruning very well (in the warmer months) and continue to thicken even in the cramped confines of a bonsai pot so try some banksias for bonsai, just be careful what you feed them.

Pines

December is summer at Shibui Bonsai and summer means working on pines.

I treat pines differently depending on what stage they are up to. Pines in ‘DEVELOPMENT’ are allowed to grow for a full season and sometimes 2 so the trunks thicken then they get cut back hard to get new shoots along the trunk and branches. Most of you will be aware that pines are reluctant to bud from bare wood so it is important NOT to let them get to the stage of having bare branches. You can cut branches back to anywhere there are needles but if you cut below the lowest needles, leaving bare wood it is likely that branch will die back.

Today I pruned a Japanese Red pine that is in the final stages of ‘DEVELOPMENT’.

Before pruning

 

 

 

 

 

 

 

 

 

 

 

 

First step is to cut back any long shoots that will not be useful in the final design. Remember to leave some needles on any branches you want to use.

Cut back the longest shoots

 

 

 

 

 

 

 

 

 

 

 

 

The lowest branch is too low to be useful so it was removed. Rather than cut it right off I have jinned it but the jin might be completely removed later if it does not suit the ultimate design.

possible front 1

 

This front has  nice trunk movement but there is  a shortage of branches on the left side.

 

possible front 2

 

 

 

 

 

There is a slight reverse taper in the trunk just near the top of the rock when viewed from front 2.

 

 

The shoots are still too long to be useful. I need to shorten them as much as possible at this stage to get more shoots as close as possible to the base of branches so all remaining shoots are cut back to leave just a few pairs of needles on each. New shoots should develop from the base of the remaining needles.

Front 1 after pruning

 

Finally, wire the remaining branches to make best use of any shoots and sub branching that are already present.

 

Front 2 after pruning

 

 

 

 

 

Now it is up to the tree to produce new buds and continue to grow. Next year it should be time to move to ‘MAINTENANCE’ pruning to fill out the branches with foliage pads.

 

 

 

Shibui Bonsai open day

Shibui Bonsai is not a retail nursery. We specialise in mail order prebonsai and starters and are normally only open for visitors by appointment but on SUNDAY DECEMBER 15 we will be throwing open the gates of our Yackandandah nursery to anyone who wants to stop in and check out our new stock, have a look at what we do or just talk a bit about bonsai.

Visitors are welcome between 10am and 4pm on Sunday December 15.

If you are able to make it, phone 0260271557 or email neil@shibuibonsai.com.au for specific directions to find us.