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Review: Junipers: Bonsai Today's Master Series

 Book of the Month: Junipers
Bonsai Today Master Series


After liking the Pines book so much, I was eager to check out this new purchase by our Club Library.  The book itself is similar in style and size to the Pines book and a few of the contributors are the same, such as Kimura and Kobayasi.  But I was put off at the start when I read that all but one of the junipers in the book was collected stock except one that was from a nursery.  I don’t know why that put me off, but it did. 

This book notes that junipers are easily adaptable to bonsai culture and are commonly available at local nurseries for a reasonable price.  Most varieties take to pruning, wiring and carving.  These traits make them a favorite from beginner to master artists.  There are 60 (or so) species of junipers; 15-20 are commonly used for bonsai.  The or so is because they note that some say 62 and some say 56 species – botanical sciences are always evolving.  Procumbens Nana, Shimpaku (Sargentii) and California Juniper are features in the styling chapters of this book.  California Juniper are hardy to Zone 8; most others are hardy to Zones 2,3,4 and 5, so we can grow them outdoors.  John Naka’s “Goshin” appears in the gallery at the back of this book.  He used eleven Formina Junipers; they have a rigid upright growth habit.  Blaaw juniper are noted for their vase shape and European popularity.  This was one of John Hill’s award winning trees at our 2011 show.   Blue Rug junipers and Juniperus prostrata are useful for semi-cascade and cascade. 

 They cover Juniper Care and Maintenance in the second chapter.  Juniper can handle direct sun with a little shade in the hottest part of the day.  The authors also recommend protection from strong winds.  With the exception of two to three days when you may place your juniper on display they should remain outdoors.  The authors also say, water only when your juniper is thirsty and then water thoroughly, making sure that all the soil is well soaked.  They recommend watering the foliage, including the underside.  They say this help prevent insect and disease problems.  They recommend feeding regularly, using two or three types of fertilizer to ensure a balanced range of nutrients.  If your tree is stressed, use ¼ strength fertilizer solution.  The book shares a poo ball recipe.

Pest treatments mentioned are for spider mites and juniper scale.  Other pests may include; bagworm, webworm and juniper tip midge.  Fungus and root rot can be treated with a fungicide containing copper (not recommended for pines).  Repotting and soil are discussed.  Most junipers prefer a pH of 6.5 and a mix that drains well.  It says that a mature tree can go three to six years between repotting.  Here in a cooler zone they say early spring is best.  Pots used are traditionally unglazed browns to grays.  The use of a metal root hook is discouraged and placing a piece of rubber under the wire holding the tree into the pot is recommended.

There is an extensive section on wintering junipers.  The key seems to be “keep them dormant to prevent damage.”

It includes both written and visual guidance on thinning foliage and the importance of continually pinching back new growth that extends beyond the silhouette you are maintaining.  They say that the pinching will encourage back budding and prevent bare sections on branches.  If you miss removing wire before it cuts in; you are consoled by a note that the tree will heal over in two to three years.  At the end of this chapter is a detailed chart showing a variety of horticultural items over the 12 months of the year.  For cold climates only August did not show fertilizing. (I guess my fall-winter use of poo balls covers this.)

Ramification is a seven-page chapter.  Despite being short on text it seemed important to me.  The authors say that a bonsai is not considered “mature” until it has achieved tertiary ramification.  They also say not to pinch to late in the year when cold weather is approaching or the twig may die.  In the second year of training they say to let the new growth extend 3” – 4” before cutting it with scissors back to a few sets of needles and then wire the twigs.  After that it should only be necessary to pinch new growth as the foliage pad has been established.  Take care not to let the top growth become to heavy, robbing strength from the lower branches. 

The next six chapters show styling or restyling collected plants.  The focus is on jin and shari selection and development.  They also show foliage thinning and wiring.  Just beyond the midpoint of the Juniper book is a chapter on Layering.  To me the technique seemed similar to taking a cutting, but leaving it attached to the trunk.  In the layering pot they use 2 parts sand and 3 parts sphagnum moss. 

Emergency Treatment is a must read chapter.  It explains that if you discover a condition such as root rot or severe pot bound conditions effecting drainage and its not transplanting season, make holes using a chopstick to improve drainage.  Fill the hole with river sand.  If you discover root rot all dead or damaged roots need to be removed and even the pot will need to be disinfected.  Water afterwards using a fungicide and rooting hormone such as SuperThrive. 

The chapter following Emergency Care showed Urban Salvage followed by a chapter on creating a cascade.  Wiring and raffia techniques are shown.  They remind the reader to pinch the apex of Cascade style trees to balance the energy to the cascade branch. 

The final chapters show Rock Plantings and Collecting California Junipers from the wild.  California Junipers are Zone 8; too bad.  ~ Ken Schultz