Extreme Tree Care: Corrective Pruning (Part 2)

Tree growth is impacted and controlled by three general factors:
Genetic predetermination;
Site impacts, which we’ll discuss in this post;
Nutrition quality/defects

​In the first installment of “Extreme Trees: Corrective Pruning”, we discussed the internal directive of trees to direct and limit a tree’s vitality, quality, and size.  Just as genetics drives a tree’s behavior, so, too, do outside influences disturb or enhance the growth.

​By far, the most common site impact is a ” too small” planting zone.  To summarize the last article, “big tree+small space = pruning”.  So, too, does a too-small root zone.  When the tree grows beyond the root space limits, deadwood and disease can take over.  A common error in Indiana is the installation of foundation plants too close to the house.  Ornamentals: Crabs, Redbuds, Dogwoods, Japanese Maples and the like are placed too close when they are small.  The result is ongoing pruning!

Planting sunny-site plants in shade spaces or shade-loving plants in full sun almost always guarantees pruning as the plants struggle. In both situations, the leggy, thin growth produced in shaded sites or the scorched, damaged of the sunny, hot sites mean pruning will be necessary.  Unfortunately, this is a short-term fix and for most plants in these conditions, removal will be required eventually.

We have now discussed some reasons for necessary pruning.  There are also methods of decorative pruning.  Pollarding, for example, is an interesting European pruning style where the tree’s shape is determined at a very young age.  All the annual growth is pruned off in the desired configuration.  Each year, all new sprouts are pruned off.  Each cut will produce two sprouts, and the pruning point will swell with responsive tissue, creating a “club”.  Each year, the “club” will send out dozens of sprouts several feet long, which are then pruned off to reveal desired architecture.  The pollard planting seen by most Americans is the grouping of London Plane trees at the American pavilion at Epcot Center in Disney World:

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American Pavilion, Epcot Center: The Trees on the left of the picture have pollarding-type pruning.

Topiary changes the attitude of any site! (Click on the picture to check out “Sarah’s Seedlings” for some other fun topiary ideas!)

Topiary is a cultural practice where a shrub or tree is ‘sheared’ to form geometric shapes or animal figures.  Again the intense and expensive practice requires planning and many prunings a year to create and hold the shape. Unlike pollarding which build its form on the plants natural structure, topiary works without regard to the plant’s predisposition, and survives by the pruner’s will.  This highly skilled practice has application in Midwest homesteads. However, they require repetitive treatments, intensity of will and are high cost. At the very extreme, is Japanese Bonsai, which require at minimum monthly pruning cycles.  Once you have decided to prune your plants in a creative manner, the issue simply becomes one of investment.

Trees require pruning for a variety of reasons.  In most yards, the primary directive for pruning is space or location, although homeowners and site managers also prune for aesthetic purposes.  Talk to an arborist as you’re making your decisions to plant ANY tree to insure that you have the right plant in the right location, and to establish a plan to help you maintain your vision.