japanese garden master pruner

Osmosis Garden Journal

by Michael Alliger
Master Pruner

Welcome to the Osmosis garden journal!  We in the garden will be writing monthly installments relating our horticultural endeavors.  Attention will be given to pruning; grounds maintenance, such as weeding, sweeping, raking, and insect control; planting and transplanting.

Also to be discussed will be design considerations including the specific roles of plants and their relationship to each other as well as to other elements like stone and water.  This may naturally lead us to touch upon the philosophical notions informing the design.

It is fitting to begin in January not only because it’s the opening of the calendar year but also it being deep winter the garden is relatively at rest.  The mention of seasons in Northern California often brings questions:  when is spring? Do we have autumn distinct from summer?  And when?  So let’s name the seasons as we see them by the months they include here in our area keeping in mind that those in other areas (even micro-climates) may experience them differently.

Winter: December through mid-March
Spring: mid-March through mid-June
Summer:  mid-June through mid-October
Autumn: mid-October through November

For our purposes the seasons are based on air and soil temperature; sunlight levels and  rainfall.  Knowing the seasons is important because they present us with opportunities and deadlines.  For instance, deciduous trees (those that annually lose all their leaves) begin doing so here roughly in November and December.  This provides us a window within which certain pruning approaches may be employed.  Though with the advent of new leaves around mid-March winter pruning ceases in order to allow the tree to benefit from the stored energy used to push out these leaves.  Opportunity and deadline.

Then let’s be on to January!


Cooler temperatures and  shorter days of weaker sunlight  bring a decrease in plant and insect activity.
This period allows us to do two types of pruning: structural (i.e. heavier) and winter silhouette (i.e. finer).

At Osmosis we have a Monterey cypress (like those on our Sonoma coast) with a design height of 15’.  It takes significant pruning to prevent it from “escaping” to it’s natural height of 60’.  This heavy structural pruning is relegated to winter since warmer season are conducive to insects which might attack the tree having been attracted by sap from large pruning wounds.  Relative plant dormancy also minimizes need for photosynthesis  allowing us to remove more than the usual percentage of branches and foliage.

Pruning for the winter silhouette is also part of this season’s work.  Here we are focused on deciduous trees such as Japanese maples, magnolias, flowering cherries and plums; refining winter’s leafless look into a thing of beauty.  This pruning is subtle and may go unnoticed by the casual observer though reaping long-term benefits in the coming months.  Maintenance of proper scale (height, width and density) is key in gardens influenced
by the Japanese style, as is Osmosis.  Winter silhouette pruning is the removal of relatively thicker branches as finer growth appears over the years.  This allows for a lighter, more natural look in spring and summer.  Less blocky.  As with most Japanese garden pruning the work is as much or more about future development as the present result.

Grounds maintenance:

Irrigation:  With drip irrigation turned off (ONLY IF CONSISTENT RAIN IS OCCURRING) some spot watering of areas under eaves or other protection may be required.  Hose-bibs and other exposed pipes should be wrapped to prevent freezing.

Weeding:  Rain brings weeds and so one of spring’s predominant chores begins in winter.

Raking/sweeping:  While practically a daily chore raking is lessened once deciduous trees (e.g. oaks, willows) have shed, at Osmosis we have large quantities of bamboo and a giant bay tree that drop leaves year round.

Repairs: As plant activity slackens time is allowed for small repairs of fences, gates, etc.

Tools:  Hand tools like hoes, rakes and shovels are given a thorough cleaning, sharpening and oiling.

Misc.:  Specific clump grasses are cut back.
Supplies (mulch, fertilizer, etc.) are inventoried and re-ordered.

Thank you!  And please enjoy this season’s gift of RAIN.