2017 April Juniper Demonstration

Trevor McComb, Bonsai Art Nursery, Heatherton

Despite the threatening rain, many Members met in East Kew to hear Trevor talk about junipers. Trevor was not feeling well but did an admirable job sharing his knowledge of junipers and answering questions. Some of the information shared by Trevor is included below.

Junipers are very popular trees worldwide with over 60 species. There are no species indigenous to Australia. Of these worldwide species, about 4 or 5 are commonly used for bonsai. The Juniperus procumbens is good for bonsai but not as popular as it used to be. It can be a bit prickly. The Juniperus chinensis ‘Shimpaku’ is very popular in Japan and it is not unusual for the majority of trees in Exhibitions to be this variety. This variety does very well in Melbourne and grows most of the year unlike the short growing season in Europe and Japan. They are drought resistant, can be grafted and suit most bonsai styles. They are very flexible.

Comments by Trevor are included below:

Shimpaku vs Sargents - Are they the same? Internet sources suggest they are not the same but related. Juniperus chinensis cv. sargentii var. shimpaku is the botanical name suggested by one site although it sounds like the experts are still debating the issue.
Phoma - a fungal disease can be an issue with some junipers. Branch tips start to die. It can move to other Junipers. It can be treated by cutting it out and using a fungicide containing Copper Oxychloride.
Junipers don’t like oil based sprays so tread warily if you plan to use one of these to treat a problem.
Trevor feeds his junipers with slow release fertiliser in the potting mix and a variety of organic fertilisers to encourage micro-organisms.
Watering - let the surface dry out between waterings.
Shimpaku’s are very flexible and can be easily wired. They are slow growing so wire can be left on for 4-5 months. Shorter periods apply for other varieties.
Repotting Shimpaku is best done in early spring or the month after Easter but can be done throughout the year providing extreme conditions are avoided.
Shimpaku generally strike well.
Juniper squamata grows up to 5 times faster than Shimpaku but they are brittle and hard to strike.
Healthy shimpaku can be trimmed almost any time provided you avoid the extreme periods. They shoot back very well.

On a more general note, Trevor encouraged aspiring bonsai artists to think about what they want in 5 years. In particular, how can you ensure you can focus on developing the art in your better trees and avoiding the time required to manage small nurseries in your backyard. Finding older material can get you there quicker. Keep in mind that as trees get older, they can demand more of your time.

BSVApril 25, 2017