Question
Oak tree in front yard
I live in Sarasota Fl and am now required to hook up to the city sewer sytem. My septic tank is next to the house, in the front, between the house and a large Live Oak (see photo). Connection requires that the new sewer pipe be run from the street, past the Oak to the house. It appears that at least a quarter to a third of the root system could be affected when the trench is dug for the pipe. My question is, is this likely to be highly detrimental (fatal?) to the tree, and could you suggest steps that could be taken to minimize the damage to the root system. Thanks for any advice you can offer.
AnswerIt will not be fatal BUT you may get dieback of some of the limbs on that side of the tree crown.
If you damage more than 30% of the trees roots the trees foliage will show major die back or maybe part of the tree will die. The trees root system is in the first 12-24 inches of soil and a trench dug near the tree will cut the root system. To estimate the damage draw a circle around the tree out where the branches reach (width of the branch spread) and then make aline through the circle where the trench will be. This cut of the "pie" will be the amount of roots cut. If this is more than 25-30% of the circle you will get major damage to the tree.
Another method would be to tunnel under the tree and the roots this would cause no damage to the tree. Here is a web link to this type operation. http://www.tlcfortrees.info/what_will_damage_trees.htm
Another serious mistake is to allow machinery to drive under the trees and over the roots. This will cause compaction of the soil and kill the roots and greatly damage the tree. Maybe as damaging as cutting the roots. Place barriers around the trees and do not allow machinery or piling soil etc under the trees during the construction. Here are a couple of web link to information on this.
http://www.ext.colostate.edu/pubs/garden/07420.html
http://www.extension.umn.edu/distribution/housingandclothing/dk6135.html
