Japanese maple repotting

It's been a winter with mild temperatures and a lot of rain in southern England. Some of my maples have already started budding so I began to do their repotting sooner than I had planned. These maples seem to begin their summer growing based purely on average temperature.

The inspection of the roots is important. Soils and growing conditions are of great interest to bonsai growers - as you can tell by the number of opinions on soil mixes out there. It is also an opportunity to get hands on and fiddle as opposed to sitting back and watching them grow ever so slowly.

My maples are grown in the classical Japanese method of graded layers of Akadama. A coarse drainage layer topped with finer particles for the roots. This is the technique I have seen in many of the old Bonsai Today magazines which had translated articles from old Japanese nurseries. I am deviating now by using a drainage layer that doesn't degrade and introducing more ingredients into the main body of soil that won't degrade.

I suppose a few hundred years had taught them how to grow maples in an optimum fashion with Akadama. They do write a great deal about how the roots effect the branches of the plant above - so I'm hoping that my root ball full of lovely fine evenly radiating roots is going to give brilliant foliage this year.

Overly strong big thick roots can result in some parts of the foliage getting too vigorous and giving excessive inter-node length.

It seems to me that as the number of buds was increasing that the inter-node length was getting shorter.

They advise adjusting the drainage layer to suit the amount of watering and fertilising - my use of liquid fertilisers will alter this old advice as the soil won't clog up with organic debris. I have also read that some no longer bother with the drainage layer. I am still going with a layer of coarse baked clay on the bottom of all my pots.

Its pot was well shaped internally and after the wire was removed it came out very easily. The condition of the roots on the sides of the pot were not brilliant. This maple had been standing outside in the winter with no protection from frost or rain so this may be the norm.

This one was grown over a coarse drainage layer of Biosorb. The two distinctly different substrates made it easy to cut back the base of the roots to just below their old level.

Once the roots were out of the pot they were untangled and combed out - any crossing or thick roots were trimmed back( there were not many of these ). The roots were now in good condition as they are already been straightened out from previous repottings and were radiating out evenly. A few new surface roots were running circles around the trunk and were removed. The tree had been in this soil for 2 years and was ready for a trim. I did clean the bottom of the root ball as well - happily there was not much there other than lots of fine roots.

Most of the old soil is removed. This was 2 line Akadama after 2 years outdoors - I saw very little degradation of it.

This maple is now coming into its 7th year with me. The trunk is 6cm thick and the roots above ground at 12cm. It is starting to look very attractive. It is also developing a rather nice bark.

I am gradually moving away from Akadama so this is about 50% Akadama and 50% Fuji volcanic grit. I am only using Fuji volcanic grit because its what I have on hand that won't degrade - any other hard modern substrate will suffice. All the substrate is mesh graded and dust free. In addition I have added a large helping of rootgrow to help it along. I have found that this gives the maples a good deal of extra energy.

I will continue to grow these with Canna nutrients. This year I will use the Hydro Vega product which is for run to waste hydroponic systems using inert substrates ( basically what I'm doing with bonsai ). I did also apply Rhizotonic to when I gave it its first watering to help the new roots along.

The first leaves are out ( repotting timed perfectly ) and I expect the maples to be in full leaf by in another few weeks.

Oak buds are out!!

 I was out on the lawn today with the cat doing my daily check of all the trees when I noticed that the Oak was extending its buds.

I've cut it back quite a lot over the winter and done some light wiring to keep it all going in the right direction. With experience growing this species I'm learning the correct shape and size. Its important to match the size of the ramification and length of the nodes with the leaf size. I've also done a better job of aiming the new growth this year.

Really suffering with water stress on the maples after they were repotted. The new growth has been explosive and the poor trimmed roots just cant get enough water up. The terminal buds are aborting on a lot of branches - which leads to very ugly nodes later on. I took them outside and hosed them down to cool them off and give extra moisture. Almost like treating a recently collected tree. Shade and loads of water on the foliage.

Luckily the roots are growing almost as quickly as the foliage and the pot will be full of them soon - if not now already. This one seems to be throwing out big thick white roots - whereas the Deshojo roots are finer. A lot to learn about this subject. The pattern of drying on the Akadama is quite noticeably different to a month ago so the roots are spread much wider already.

Wabi-sabi

I completed the repotting and root maintenance on my maples for this year. A bit early - but i suspect they will wake up early this year. They are having their third repot and and potting up to their final pot sizes. All of them at least a year late for their new pots - but poverty and the ongoing recession put and end to any new pot purchases over the last 2 years.

Luckily they were in well shaped pots - with no internal lip - and a nice taper on the walls - so they popped out easily. This is the root system of my Deshojo - they are in nice(ish) condition - but heavily compacted. A little bit dark and a tiny bit stinky.

 

A little help from the cat to get the positioning in the pot right. The position was adjusted for favourable wabi-sabi before soil was packed in.

 

The roots were combed out and any crossing ones removed. A little shaking and poking to settle the soil in and it was time for watering. The roots on the bottom were trimmed in tightly so there was no spring in the base. This maple is a random Acer Palmatum i got from M&S. Its thickening nicely and has a wonderful autumn colour - a deep wine red. The soil is old Akadama from before the Fukushima disaster so there is no danger of radiation. Its got a lot of Fuji grit in it as well - 2 scoops to 4 of Akadama i think - it looked right.

The soil mix and potting method is exactly as the Japanese nurseries do it. Their centuries of experience with this species gives us valuable knowledge. I have varied the particle size a little - the palmatum random getting the larger particles. The drainage layer is biosorb though. The rest is 1.5 to 5mm akadama with 25% fuji grit. plus minus.

I do wire the big maples into their pots as the wind can easily knock them over. These wires will also anchor the guy wires for the training rigging later in the year.

I gave them a really deep watering to get all the dust out and make them at home. Cat is assisting as usual. Note I am barefoot watering the plants on the lawn in January.

The soil level is well below the rim so that it will be easy to water - even after some growth and the usual moss invasion. This pot also has a nice taper and no internal lip - so when its time comes it will come out easily.

Here is the Deshojo's new pot. The ever present cat was assisting as usual. Really liking my new pots this year. I found a terrific vendor on Amazon with a really nice selection - and amazing fulfilment.

I'll pose some nice pictures of them in their new homes in the following weeks.