Working with Eucalyptus nicholli as bonsai

[PeterH]

This was one of a series of articles for our club newsletter.

Working with Eucalyptus nicholli as bonsai

Based on information provided by …… http://www.koalanativeplants.com.au/com ... nt_id=2056

A popular and most attractive ornamental eucalypt from the New England area of NSW that is grown extensively throughout Australia and overseas. The small thin grey-green foliage and the pendulous branches make for a most handsome tree growing to around 20m high in good conditions. Nicholii is suited to most soil types including poor soils, adapts to most climates and is frost tolerant down to around -7°C. White flowers are seen in Autumn and the bark is a fibrous grey-brown. It’s one of the most popular and best known of Australia’s Eucalypts and has been grown as a garden specimen for decades



[General description/information about Genus/species, including typical growth form and habits such as apical dominance]

1. What attracts you to working with Eucalyptus nicholii as a bonsai subject?

The challenge of creating a distinctively Australian Bonsai, using Eucalypt as the material. Over the past 12 Years I have found that the nicholii responds to most of the regular technics used in Bonsai although at different times of the year.

2. What do you look for when selecting stock to work on?

Much the same as normal Bonsai... Healthy, some movement in the trunk. I have only found nicholii in 4” pots in nurseries, so what I buy is either put into larger pots or in the ground and grown on. The nicholii is a fast grower and can put on good size over a two year period. As with none natives it is important to shape the trunk when still young.

3. What is your general approach to styling Eucalyptus nicholii? What are you aiming for in working with Eucalyptus nicholii?

I am trying to achieve the look of an aged Eucalypt. I study trees in the bush and have noticed particular points that make a Eucalypt different. As a young tree a Eucalypt has straight branches and a round full canopy. As the tree ages it drops lower branches and has die back which creates the extreme movement in the main branches. Also the foliage separates into layers or clouds. This process highlights the trunk which becomes the main feature of the tree. When the tree ages its trunk becomes hollow which also adds character to the tree. As motioned before I have found that the nicholii respond well to Bonsai technics and has some of the basics of leaf size reduction and gnarly bark .In short I’m trying to recreate images of what I see around me heavily influence by the country around Cooma with what I’d consider a versatile native.

4. What is the best time of year to:
• prune?

I prune heavily at the end of November and again at the end of December into early January. The rest of the year I finger pinch the foliage to retain the shape.

• trim to develop branch structure and leaf mass?

This is a constant process to keep the shape and to balance the tree. If the foliage mass on one branch is less than the others it is probable that you will loss that branch.

5. How does it typically respond to:
• hard pruning?

As mentioned above if done around this time the tree will bud back. Be aware that Eucalypts will bud back at the base and it is important to rub these off. If this is not done these throw backs will become dominant and eventually kill the rest of the tree.

• trimming?
In particular, does it bud back on bare wood? older wood? Does it shoot back near the cut or further back? Does it shoot back strongly, reliably?

When trimming hard I will cut back the branches too about two leaf nodes, this would be done all over the tree. I would not trim a weak branch. It will bud back from the two leaf nodes left and also back on old wood, around scared areas and at the base. The unwanted buds are rubbed off over the next two weeks or until the new growth hardens.
When doing alight trim I finger pinch the foliage. The tree will respond by budding back about 2 nodes but generally not on the older wood.



6. How do you go about developing the branch structure and foliage that you want?


When I prune hard, the budding back gives me options on whether to use the new growth or not. When these new branches are soft they can be wired into what ever shape I want. When the branch is in place I keep pruning the end foliage until I have a mass of tertiary branching. I then go through this branching and thin it out to create a cloud (layer) with some structure.




7. How do you go about maintaining the style once achieved?

Regular hand pruning, or tip pruning. Occasionally thinning out the foliage. ( Less over winter ). Wiring or using string.

8. What fertiliser(s) do you use and when do you apply them?

I use native Osmicote twice a year in August and again in December. Also diluted liquid seaweed around September and again at the end of January. Sometimes I will use Dynamic lifter around October.

9. What pests and diseases have you encountered with this species/group? How do you treat them

Mealy bug and leaf eaters. I generally treat with Confidor or any systemic pesticide except Rogor. I find that if the nicholii gets full sun it rarely attracts any bugs.

10. When do you generally re-pot and what potting mix do you use? Are there any particular potting requirements?
I repot in September/October when the night temperatures are around 10deg or above and day temps are around the early to mid 20”s. I have tried repotting from as early as August through to as late as mid December with success.
The potting mix I use is the Rich Gro Australian Native Mix with an amount of Zeolite thrown in until it looks right. The KISS principle.

11. What growing conditions (light, moisture, shelter) do you provide – in summer? in winter?

The nicholii is watered twice a day during summer and once a day during winter unless it rains. The nicholii likes full sun and also uses more water than the other trees in my collection. This causes me to do two things during the hot months.

1. Is to keep foliage to a minimum
2. To put it into semi shade (I only do this because I work during the day and it helps the tree survive till the next water)

12. What is the most important advice you could give to someone starting to work with (Genus/species) as bonsai?
The Eucalyptus nicholii loves full sun. Don’t prune hard in the cooler months from January to September. Due to the fast growing nature of nicholii watch any wiring.

[anttal63]

peter everything that can be said about your tree has. for me its probably the best euc i have seen to date. this article is brilliant, you have answered all my questions and given me the confidence to keep working mine. thanks pal

[aaron_tas]

cheers peter,
an excellent post, most informative
you have answered the questions i was testing...
thank you for saving me time