Tuesday, 26 December 2017

Post 248 Next stage for the air layered Clerodendrum

In my last post I covered the air-layering of this large trunked Clerodendrum hetrophyllum. This picture shows the air-layering in progress with the dam still in place around the cut site.

And then after separation and repotting. I also trimmed back the branches and foliage to reduce the dehydration load on the tree, having reduced its root capacity.

 Now just two weeks later and every branch cut is reshooting, with multiple shoots at each site.
This is typical of Cleros and it is one of the reasons why the species is such a good bonsai subject. An abundant capacity to shoot back on bare branches makes for easy bonsai development.
At separation it had a very good root supply and so in the last two weeks and has firmed up nicely in the pot. It's prime time to get on with the next stage of the rejuvenation work.

 Looking into the basic structure of the tree there is a straight section of the upper trunk which visually conflicts with the rest of the attractive taper and movement.

The branch structure is also pretty poor. Not nearly enough branches is the common failure of many bonsai. That trunk really deserves better and so I'm going to have to start again from scratch. When the tree was collected there were branches cut off leaving a number of flat faced scars and deadwood. The existing branches developed from the callus tissue that formed around these old cuts.

In repeating that process of branch renewal it is likely that new branches will again come from callus around new cuts and I may not get enough branches again. If that happens then I'll use grafting to get the right number and location of branches. I have lots of cuttings struck in small pots ready to go for just that purpose and over the next couple of weeks will get them ready for hairpin grafting.

 Here you can see the section of trunk that has to go. The branch to the left of the intended cut will provide an opportune apex.

 Branches coming off.

 And more.

 Removing that trunk section down to the left hand branch stub.

 Final view from the front.

 From the right.

 From the back.

 And from the left hand side. There are lots of cuts on the trunk. Some are from the removal of recent branches and some from the scars from the original removal. I've carved out concave cavities in all of them and then sealed (not shown here) them all with cut putty to seal them up and assist recovery. With peak summer temperatures and plenty of water I'm expecting it to produce new shoots within a few of weeks.

Sunday, 10 December 2017

Post 247 Air layering of a Clerodendrum

This is a story about the air layering (or ground layering) of a large club tree, a Clerodendrum hetrophyllum, that was done at a club meeting on Sept 23.
The 'Clero' is a fantastic species for bonsai in this part of the world. It's a native of Reunion in the Indian Ocean and it came to tropical coastal Queensland in colonial days as a hedging plant for gardens. Since then it escaped the confines of gardens and is somewhat feral in a number of locations. But its still a great species for bonsai, robust, shoots back, small leaves and great fibrous bark.

The first three pictures are of the trunk of the tree from a number of different directions.

  Suffice to say the nebari was pretty poor, comprising of very large primary root structures and no fine root development and trunk flaring. It was this poor appearance that was the motivation to complete an air layering or ground layering, to build a quality nebari to match the trunk.

  This is the start of the work. Once a line was drawn around the base, the cut could be made.

  Having cut and removed the ring of bark, plastic sheeting was placed over the surface of the potting mix to make with a tight fit against the trunk of the tree. The purpose of this sheet is to minimize any upward root invasion of the planned layer potting mix. Without this barrier the tree's roots would rise up into the potting mix placed around the cut and confuse the signals about the layers success.

  Here the dam (just a cut off garden pot) is placed and filled with regular potting mix.

  This is a picture of the tree 11 weeks later on December 9, just before stage two of the layering - the separation.

  The first indication of success of the layering is roots just below the surface of the potting mix. With the plastic sheeting in place it is unlikely that these roots have come up from the original root mass.

  By just lifting slightly the dam wall the second favourable sign is more root evidence.

  Taking the dam away entirely reveals very healthy and abundant root development.

  Here the surface is raked away from the trunk to reveal very good root development from all around the trunk.

  The pot was then tipped on its side to look between the plastic sheet and the layer cut to confirm the roots have come from the layer cut, making separation possible. Here you can see the major components of the original root structure where they have been cut through. There was a handsaw in the previous picture but this cut needed a chainsaw.

  This picture shows the root development from the layering. To prepare for planting the roots were gently raked out radially from the trunk so that as they develop and gain weight they will be aligned to create an attractive nebari.

The final picture shows the tree returned to the poly box to grow on and stabilize. The branch structure was trimmed back to reduce any wind load and also to reduce any dehydration pressure from the much reduced root mass. At this point the tree is just experiencing what any other tree would during a spring root prune and will no doubt respond in the same way, with abundant growth. After a month or so for new roots to grow and stabilize the tree, the next stage in the rejuvenation can start - building a new branch structure - one that reflects the broadleaf character of the species and will leave the future bonsai looking like a tree!

Wednesday, 6 September 2017

Post 246 Ficus root pruning and sacrificial branch removal

Here are a couple of Natalensis that I've been developing with sacrificial branches. Its time to take the sacrifice off one off and root prune both.

 This first one is one of three that I've been growing for about 3 years. You can see some pictures of them all in an earlier post (232) here.
They all started as small cuttings and I allowed a vertical sacrificial branch to develop on each. The idea was to develop a small tree with a large trunk in the shortest time.Here you can see the small tree developing close to the pot and then the scale of the sacrifice branch.

 Here is the point of union, at the 'back' of the future small tree.

 Here it is removed.

 From the front before starting the root work I did a little branch work and defoliation to reduce the dehydration risk. The style will be classic ficus architecture, certainly not an informal upright with dominant single tapering trunk.

 The first cut in reducing the roots.

 After a thorough root raking to see what was what.

 Cut back to rearrange and refine the roots for the next stage of growth. It had a really large root from the left which had to be removed. These things are tough and will have no problem with this amount of roots remaining.

 Re-potted and ready to go again. Still too soon for a bonsai pot. Perhaps in another 12 months.

 The second one is a tree featured in 'Bonsai Foundations'. It is a five year old Natalensis with a heavy sacrificial branch that I plan to keep for the time being. I use this tree in teaching and demonstration and so although the branch really should come off I'll leave it there with a minimum of foliage.

 Here it is root pruned back and foliage clipped to minimize dehydration.

 And then back in the same oversized pot for another year.

Sunday, 3 September 2017

Post 245 Root pruning season

Spring is here in Brisbane even though the nights are still getting down to 12ish, C. That means on the bonsai calendar that  its root pruning season. I started about mid August with all the deciduous trees, then my natives and now its the turn of the ficus.
Here are a couple of other trees I did in some of the earlier work.

 First up is a dwarf Hinoki that I acquired this year. Its been in a garden pot and I wanted to replace its growing media and set it at a different angle, both good reasons for a repot.

 Once out of the pot the highly organic material can be seen. It has grown pretty well in this material with good dispersed root penetration. But none the less my plan is for a much more granular open mix to replace it.

 This is about as much as I want to take off it this time.

 This is the replacement mix, one third diatomite, one third zeolite and one third mini bark (pre-composted).

 Repotted and ready to go for the coming season.

 Next up is another conifer; this one a blaauw juniper. Its been in this shallow pot for the year in my standard four part mix.

 Nice healthy root growth and fully penetrated throughout the mix. At this time of year I find it increasingly difficult to get moisture into the pots. With lots of root growth throughout the medium the spaces for water penetration are blocked up. As a result the trees produce a lot of fine feeder roots in the top 20 to 25mm of the pot further impeding flow. So the top 25 to 30mm gets wet when watering but not much gets further down. Another really good reason for root pruning and repotting.

 Pruned back and ready to go again.

 Back into the same pot in the three part open mix.

 This is an upended Swamp Cypress.It grew all summer in a shallow pan of water and was starting to push the tree up out of the pot. When you see the roots in the base you can see why. This is a tree that I'm planning a radical cutback and restyle starting with a reversal of viewing position so I'll set the tree back in the pot with this in mind.

From all that mass of roots back to this, a small tight block of fine feeders. Past experience says that the tree will relish this cutback and launch itself into the new season with a burst of growth.