Thursday, April 25, 2013

Staking Abstractions

Posted by Eric Hammond Adams County Extension

While walking my dog around my neighborhood in between blizzards I have noticed some very um…..artistic methods being used to stake recently transplanted (and not so recently transplanted) trees (please note I’m not endorsing any of these methods). 

A stately cape-like staking pattern. This is a well established tree, does it need the support?

A clump planting of Aspens staked as a group.  The plants are already being pulled inward by the straps.

A resourceful approach which shares stakes between trees. However, the plants are staked so tightly the guideline could also serve as a fence.
A single stake very close to the tree.  This can cause
the growth of the tree to curve away from the stake.

A three foot tall tree with three stakes.
The variety and creativity of methods used got me thinking: why do we seem to have such a fixation with staking trees?  It’s an extra step in what is already a labor intensive planting process and, at least to my eyes, is unattractive.   Do we find it comforting to see the trees anchored securely in place?  Do we feel we are nurturing and giving them a better chance to survive in the landscape? Is staking so common because many nurseries and tree care companies recommend it?    
I suspect the simple answer is correct more often than not-  newly planted trees are staked because we think they need it.  We worry they will shift or tilt after planting due to wind, settling of soil in the planting hole, small children using the lower branches like monkey bars and etc.  
There are probably other less straightforward reasons as well.  I know when I plant a tree I have a strong financial and emotional investment in its success or failure.  Accordingly my instinct is to do everything possible to nurture and protect the plant.  Psychologically, I guess I can understand how it might seem comforting to see trees staked tightly to the ground secure and unmovable in their planting holes.  Maybe the urge to stake grows out of such feelings.  
If this is the case the question becomes, is staking really a practice which nurtures trees newly brought into a landscape?  
It turns out the answer almost always no.   In most residential settings if a tree is planted correctly staking is not necessary to support the tree and in fact it can have serious consequences on the long term viability of the plant in the landscape.
How Staking Impacts a Tree:
Staking has a number of effects on trees.  Some of these are related to the growth of the staked tree others are related to actual physical damage caused by incorrect staking methods.   The natural swaying of trees in the wind promotes growth in areas that help the plant withstand wind; mainly it promotes an increase in root growth and an increase in caliper (trunk diameter).   Conversely, when a tree is staked it may have less root and caliper growth and instead grow taller.  Plants that are staked tightly can even develop an abnormal taper to their trunks.  In this scenario, a tree moves in the wind above straps stimulating caliper growth in the upper portion of the trunk while tight straps prevent any growth-stimulating movement in the lower part of the trunk. 

A small tree staked tightly and then supported with a metal stake.
Very secure but will it develop normal trunk taper?
The straps used in staking can also physically damage the trunk of a tree either by repeatedly rubbing against it or in the worst case, if straps are left on too long may girdle the tree.

The twine used to stake this tree was left on too long and is now girdling the plant.

When should a tree be staked?
Given the potentially negative effects of staking, it should only be undertaken in very specific situation.  For example, on very exposed and windy sites staking might be necessary or in specialty situation such as the transplant of abnormally large conifers.  Staking may also be used as way of protecting trees in high traffic areas.
If a tree does need to be staked, it should be staked loosely enough to allow some movement in the wind.   Nylon straps are preferable to other materials.   It is extremely important to remove stakes once a tree no longer needs them as the straps can girdle the plants trunk.  For trees smaller than 2” in caliper this is normally one to two seasons. 
Spring is a great time to plant trees (and I’m sure at some point spring will come to the Front Range) just remember- Think before you stake.

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