In November 2015, the very early days of this blog site, I wrote about Metrosideros excelsa or Pohutukawa as Bonsai and included a few photos of these magnificent trees in nature. This tree is also known as the New Zealand Christmas tree. The link to that blog post is here.
For this blog post I will style a Pohutukawa as a Bonsai. As can be seen from the photos in the linked post, these trees very naturally present as multi trunks with great root structures and the very prominent aerial roots. it is this root structure and especially the aerial roots that make these trees ideal for root over rock designs. This tree will not be a full root over rock, but a rock will be placed next to it with roots growing over the rock.
This plant was grown from a cutting for a few years and these photos clearly show that these trees are basal dominant. It basically means that it will keep on growing new shoots from the base compared to tree which are apical dominant where the new growth is at the top of the tree.
As can be seen from the photos above, the first step is to search for roots and in this case roots in the soil and not the aerial roots. I find it better to remove the top edge of the plastic bag and sometimes remove the bag or pot completely. The presence and position of roots, especially radial roots will help to determine the orientation of the tree. In other words, the front of the tree and the first ideas of what the design could look like. In this case quite prominent roots were found and spread around the tree which means we can now look at the above ground structure as the placement of the roots allow us to look at multiple design options.
The next step is to remove all unwanted growth. To stay more or less true to the natural growth pattern Pohutukawa, the decision was made to design a multi trunk tree with three trunks. Really only two, but the thickest trunk has a fork which visually looks like two trunks. All three trunks have different diameters which makes it visibly more pleasing. All inward growing branches are removed and decisions are made about the three trunks. This includes things like direction, placement and length. As the three main trunks did not grow naturally in the directions needed and the centre trunk needed to be compacted, wire was applied.
The final product with a rock added to add visual weight on the right hand side and also allow a backdrop or prop for some of the aerial roots to grow over.
It is important that Bonsai trees are three dimensional. The best way to check that is to view the tree from above. Visual depth adds to the aesthetics and overall view of the tree.
As for all trees, the aftercare is now of the utmost importance. As the pot is not that shallow, not many roots were removed, but the tree will still be kept in a protected spot, out of the wind and cold temperatures. Watering is now also important as well as sun exposure. Just damp, not wet and limited afternoon sun is what is now needed for the further development of this tree.