Trees on the level Part 2

Trees on the level Part 2

On a previous post two days ago, I discussed the importance of having trees grow at the correct level.  We covered the problem with soil surrounding the lower trunk and root flares and causing rot.  I must qualify that discussion.  Some trees are tolerant of that and can actually grow new roots right out of their trunks and into the new higher soil surrounding them. 

What plants can do this?  Trees that tolerate wet and changeable conditions usually.  Willows, (Salix spp.), Poplar (Populus spp.) many vines and shrubs that are easily rooted from cuttings will also do this.  Most normal regular trees like Beech, Maple, Oak, etc. will not do this.     

When some species can grow new roots, they are called adventitious roots.  Adventitious roots are roots that arise from cellular sources that are “accidental.”  They are not where you would expect to get a root.  Cells differentiate into callus tissue and form a lumpy mass along the stem.  Then when the environmental conditions continue favorable for roots, they further define themselves as absorbing root tissue.  Soon they become more organized and actually grow out and into a real root.  Some plant hormones are involved but the important point is, some plants have the ability to change their tissues as needed and reroot at a higher level on the trunk.

Since most kinds of trees have trouble doing this, why then are there such persistent folktales about being able to add certain amounts of soil per year to trees and cause no harm?  Mostly, I think, trees do everything in slow motion and the initial assault of the new soil level takes many years to rot the crown of the tree and cause failure of the plant.  People just do not connect the installation of that new driveway over the roots of a mature tree with its eventual loss of upper branches on that side, and then half the crown and then finally death.  It may take 10 to 20 years to completely cause the tree to fail.

Humans  are on a faster time line.  A new homeowner may plan to stay in a house for 5-7 years.  If the tree fails for the next guy, he really doesn’t care. 

Here is a list of activities commonly associated with extra soil around trees:

  • Installation of septic fields filling on top of established trees
  • Driveway installations
  • Basement excavation of soil in new house construction
  • Changing the grade around buildings
  • Creation and fill of retaining walls around established trees
  • Flower boxes built around trunks and filled

What sins have you committed to your trees?


1 Comment

  1. Theron said,

    December 17, 2009 at 1:52 PM


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