Satsuki Azalea Re-pot


Your Treasure House is in yourself; it contains all that you will ever need.

Hui Hai.

This fairly small twin trunk Satsuki Azalea arrived into my collection only last year. At the time it was little more than a small bush, and when I looked at the root-ball by lifting from the pot, it was the usual mass mixed into pure Kanuma.

At the time I just gently teased the edges and potted on into a larger container, I could have run with a full re-pot at that time but wanted to study the tree further and enjoy the flowers.

I am no fan of re-potting Satsuki after flowering. Conditions here are very different to Japan, and with a depleted tree – re-potting at this time is not a favourite. Hence, I knew that I would eventually re-pot in late March early April 2011; this then is the day.

Here is the tree as I described earlier when it arrived in April 2010.

After easily lifting from the slightly oversized pot that I had used last year, I was greeted by a soggy root-ball. Unfortunately we had plenty of rain the last 48 hours. Normally I would prefer the medium to be on the dry-side; alas it was not to be. Existing roots had made some in-roads into the new soil but not as much as I would have hoped. It did however cushion the root-ball somewhat from the awful winter weather we experienced in 2010/11.

I had used medium sized Kanuma for the potting-on process in 2010 and whilst I am not really keen on pure Kanuma, it was right at the time, knowing it would only be twelve months maximum.

I do not use any  tool, other-than my favourite stainless-steel ‘chop-stick.’ For Satsuki this is a slow and steady process, as I wish to retain as much root as possible during the combing out procedure.

Here you can see the residue soil falling away. It has not broken down at all during the twelve month period.

Turning the tree upside down, I am very fortunate to have very little dead or decaying root. Most I teased away last year when I potted-on.

After a light wash you can see clearly the new root growth that has occured during the previous twelve month period.

After further washing and removal of any blackened roots I have trimmed up the entire root-ball using very sharp scissors.

Initially I had intended to bare root the tree. After careful examination however, this route was not a consideration, due in the main, that at least 90% of the root remaining was very healthy. At this stage I have removed around 20% of the entire ball.

With Satsuki, I advocate a three pronged approach.

  1. Bottom
  2. Sides
  3. Surface (last)

You can clearly see the overall health of the roots in the last image. Some further reduction and I have gone as far as is necessary. Note what I said then; ‘necessary.’ There is little point stressing the tree further when it is simply a waste of time. This is an extremely healthy root-base and I see no point whatsoever cutting in further when new healthy growth has appeared right across the tree over the last ten day period.

Here I have worked on surface roots last. All dead and roots going nowhere or crossing have been cut away.

Great care should be exercised when working on the surface. When Satsuki are -pot-bound surface-roots will turn downward, hap-hazard removal and cleaning up of the surface may leave a large percentage of roots in the core when you cut the surface. With Satsuki unless you bare-root, it is next best thing to impossible to trace roots; thus, cutting the surface may leave you many eventual dead roots.

I have now completed the reduction and trimming. Around 30% has been sliced away from the base, 20% from the sides, and a tidy of the surface. I am completely satisfied that for two to three years in the new mix (which I will explain in a moment), this azalea will continue to develop in terms of strength and overall vigour.

Growth has been astounding this previous ten days. Here is a worm-eye view of one area.

Looking at the balance of Kanuma left in the old pot, you can see how  it has already started to block the mesh. These were larger particles; I don’t usually worry about a grit layer for such a short time.

Collecting up a handful and gently squeezing you can see what happens.

It makes a great face-pack; as it dries it really does dry your hands and make the skin very tight; hence why I don’t favour a 100% Kanuma medium.

Again, it can be seen very clearly how easily mesh can be blocked and lead to eventual water retention; rotting the bottom layer of roots.

With my root-ball fully prepared, it is now time to select a pot from what I have available. I immediately discarded my first choice.  Oddly this was to be the pot I was convinced I would  use. By actually dropping the tree into a pot and standing back to view, usually always tells you if it is at all right for the tree.

The following match is the over-size pot I used last year when it was potted on. It may seem OK, but as a square pot it is all wrong,  served a purpose though.

Erin Pot.

After rejecting a pot what I thought was going to be right, this then was the next one I tried. Chinese pot.

And the next: Walsall Ceramics with slight lip. Too long and not right, worth a pop though.

And the final choice; an early Erin pot.

You’ll see at the end which I went for.

I started by saying I am not a personal fan of pure Kanuma, despite the Japanese having huge success with it. The Western world has often struggled using pure Kanuma and I am no exception.

I’ve lost several specimen Satsuki over the decades; without exception I only ever used pure sifted and graded Kanuma. One of the difficulties is, if left too long between re-pot’s, the hair like roots grow through each particle, making it extremely difficult when preparing roots for the next move.

I have had a couple of azaleas in pots that I have played with over the years. After much trial and error I believe I have settled on what is a cracking mix and one that works well. If you have a Satsuki that has been planted in 100% Kanuma and you wish to change mixes; do it gradually, this way the tree acclimatises to the new mix and will not turn its nose up and not grow into it.

Over say three re-potting’s I have changed the mix completely but still retain a percentage of Kanuma; two-fold; it keeps the tree happy as Kanuma is still present. And I had ten bags of the stuff, so wanted to at least use it!

Here then is my mix that has given a new lease of life to my Satsuki.

I start with Kiryu, sifted and graded. As this is a small tree this is my particle size. This never breaks down and holds nutrients well. Much smaller than usual recommendations. This makes up 15-20%

The Kanuma content is currently at 20% and is sized as shown here:

The combination of mixed larger and smaller particles creates some excellent air spaces rather than a squashed in compressed medium.

Next 20% is Aqua-grit. I dare say Kyodama would suffice.

I now use 15% content of chopped propagating bark. This then the only organic soil content. Bear in mind that the other elements within the medium become temporarily ‘organic,’ in-so-far they all hold nutrients to be used by the plant when required.

Next I use Akadama to 25% of the entire mix. Small and medium sized. For a larger Satsuki I replace with medium and large mixed.

I’ve always usually frowned on ericacious soil sold in Garden Centre’s, but since using this one I have nothing bad to say. It drains superbly and I cannot praise it enough. I mentioned earlier that the bark was the only organic component; clearly this has organic content.

This makes up the difference to 100% total soil components.

I use a rubber builders type bucket to mix all the contents well.

Next up is additives;

Organic acid loving from Miracle Grow. 25 mil.

Followed by level 5mil spoon of:

  1. Frit
  2. Trace Elements
  3. Iron

All components added. Once done hold handles and mix thoroughly.

Once mixed thoroughly, I now prepare some Japanese dried moss and some Sphagnum. Chop with scissors to smaller sized pieces but not so far as it starts getting dusty.

Place in a bucket to soak. Once moisture has been absorbed over fifteen minutes or so I remove and squeeze out all excess liquid.

Where I have any significant holes in the base of the root-ball I turn upside down and sprinkle the mix into all the pockets.

Once done I take the moistened moss-combo and layer lightly, holding with one hand while placing in the pot. The pot has a small drainage layer which is Kiryu larger particles and the mixed medium. Sounds easy but you need some help really. Good for me a bonsai-buddy turned up; home-made treacle tart was on offer, still warm as well.

The tree is secured into the pot. I have used non-rotting twine. It is cheaper than wire and secures the tree perfectly. If there is any slack left, just use an extra tie under the pot to pull each loop tight. Try to find roots to to run under if possible.

I have been adding rootgrow mycorrhizal fungi to azaleas with excellent success rate. I was chatting (of sorts) to a non-English speaking Japanese friend a couple of years ago and he grows nothing but Satsuki. He explained that he always added this fungi on re-pot’s and had been astounded at the recovery rate.

To the extent that he now no longer removes all flowers when re-potting prior to flowering. He went on to explain that he removes about 40-60% of flowers. This creates nice layers and allows the remaining flowers room to open fully.

Here the Satsuki is secured and sprinkled with  mycorrhizal fungi; be certain if you try this that it is fully in contact with exposed roots.

Next up I cover the exposed roots with a mixture of the mixed moss and soil. This is very carefully placed. Be careful to make certain you do not create any large and undesirable air-pockets.

After about forty minutes the moss is mixed with the soil but in very close contact with all the exposed roots.

After carefully finishing off. I now cover the entire surface with propagating bark. This helps in protecting the surface roots. I have found during post care it helps keep a high degree of humidity within the root-ball.

Well that is pretty much it. I should say that there is probably at least 101 ways to repot a Satsuki and indeed the way in which a soil medium is prepared.

I had nothing but problems with Satsuki, and since adopting this re-potting regime, I have been overjoyed with response. The tree will now sit in my shaded greenhouse and be misted several times a day. In addition I water the slabs when I remember, and this creates some wonderful humid, conditions.

I will see how the condition of the tree is when ready to flower. This will depend on what percentage of flower buds I remove. It will stay under cover for three weeks then go into a shaded area of my outdoor display house. Once in flower it will be protected from rain which of course ruins the flowers all so quickly. Once flowering has been enjoyed, all flowers and stymens will be removed. I realise this is a laborious task but one well worth doing.

Caught at just the right moment after flowering I will give the first organic feed; then continue two-weekly until late summer when I will revert to 0-10-10 to build up strength for the winter. I appreciate some consider this to be a myth, but I believe it helps.

Some light wiring has been completed on the crown. When flowering is finished I will be re-shaping this tree during summer 2011. For now it deserves a slight rest. In a few days time I will lighten the foliage along with unwanted buds. The reason I will not reduce foliage at this moment in time is so that I can regularly mist. This gives the opportunity to permit moisture intake via the leaf system rather than relying on pruned roots to do the job.

This period of time will range from a few days to a maximum of three weeks. During that period roots will be already growing well and will then take over from misting. I will until flowering still continue to mist twice to three times daily and keep in said humid environment.

Oh, and yes, I went with the Erin semi-crescent pot. First the original from last April, then after the re-pot.






4 thoughts on “Satsuki Azalea Re-pot

  1. Hi do you remove foliage/flower buds prior to the re-pot/root wash?if so how much to remove?
    Many thanks great informative post.

  2. Jasioni

    May I ask where you buy the melcourt propagation bark from as I am finding it impossible to find a supplier? Thanks Jason

    1. Mike Jones

      Go to their site and see who stocks PB in your area. prices vary greatly so shop around. I have just searched generically and found several options. Good luck.

  3. philp8

    Brilliant write up Mike, really enjoyed reading that mate. Not sure if you are aware but the annual show at Exmouth this year has the Satsuki Association in attendance….i for one cant wait to see the show. 🙂 Regards Martin .

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