Club Meeting June 2012

by Viyonne Longmore

Soil for Bonsai by Graham la Foy

The essence of this very practical talk, was that one needs to understand the importance of a good soil mix, as it will be sustaining your tree for at least a season. Another important aspect is that each tree has slightly different requirements for its soil constituents, but there are some recurring themes.

A good soil mix consists of 4 components:

  • Mineral: gravel, sand, silt, clay
  • Decayed material: friable, retains moisture, contains nutrients
  • Living organisms: bacteria, moulds, fungi, insects
  • Gases and moisture

Graham took the time to show us examples of each kind of potential component to your soil mix and discussed the benefits of each constituent. The take home message for is that each component, be it gravel or organic matter, must be well decayed so that is wont decay in the bonsai pot to a detrimental degree.

Deadwood Preservation by Trevor Venables

There are three major origins of deadwood that is used in bonsai

  • one can collect a tree that has a deadwood component on it
  • it can be created as a design consideration
  • it can occur during die back of an existing tree

Deadwood needs to be of a hard wood origin: olive, pine, juniper etc.

The essence of deadwood preservation is to prevent fungi and bacteria thriving and thereby causing rot.Trevor discussed the various options of treating deadwood, some of which is not available in South Africa.

  1. Lime sulphur: this releases sulphur dioxide which causes the bleaching effect, so care must be taken to not get it on unglazed pots. Whilst being easily available, there is the problem of poor penetration into the wood and therefore repeated applications are necessary.
  2. Enseal/ Alkalyn wood glue: this contains Zinc as a biocide, plus it seals the wood. Potential problems here would be that it doesn't penetrate so existing organisms could still cause problems.
  3. MinWax/Ronseal: these are wood hardeners but are not available in SA
  4. Rot Doctor: again, not available here, but this product has fantastic penetration and is epoxy based
  5. Bonsai Wood Sealer (created by Rudi): when used diluted 1:10 and in conjunction with lime sulphur, it was agreed upon that this was one of the best products available.

Trevor's take home message: Prevention of rot, it better than cure!

Olives by Freddie Bischoff

The western cape has an abundance of both commercial olives as well as wild olives. The key success factors in sourcing an olive is to have a plan before one digs up the olive and to be realistic about how long the tree will take to mature once potted. There are two main factors affecting the timing of the dig

  1. Climate – it was agreed that around May/June, just before the rains was the best time
  2. Tree growth stage – an olive has three main growth stages: the first is when the tap root system dominates and lasts for about 7 years. The second is when new roots sprout, the bark cracks and the tree starts to store energy (this is the time to dig!). The third stage is when the tap roots die off and the main roots forms. Hopefully this will occur in your pot.

Freddie had an extensive and very informative talk taking us through the steps of finding a tree, treating it, potting it, caring for it and then repotting it. He is also currently performing many experiments of soil types with his olives and hopefully will soon be able to give us advice on the most optimal conditions for your olive.

Freddie's take home message: Each olive is an individual, we can control most aspects of the care of the tree, but it does not always guarantee success

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Tenderly, lovingly

raking up dead leaves

in his Bonsai forest

Random Bonsai Tip

Where the primary branch is thinner than the secondary one, prune back the secondary hard, keep it trimmed back and allow the primary branch to grow unhindered until it has thickened.