November 16th, 2020Glen, about the house
Tree roots, like those of all plant life, take water from any available source whether it be natural groundwater, accumulated moisture from under your house or driveway, water from a fractured or leaking drain pipe or from your watering system.
It may be a fallacy that tree roots break into pipes, unless they are cracked or broken earthenware, but they will follow any source of moisture and certainly can make small holes a lot bigger. Once inside a drain or sewer pipe their fine, fibrous feed roots can soon grow to restrict the flow, eventually completely blocking the pipe.
It is not simply a matter of trying to trace the offending tree to have it removed once you have had the offending roots cleared from your blocked drains. There is no guarantee you can positively identify the exact tree or that roots from another nearby tree won’t enter the pipe.
The only sure way to completely overcome the problem is to repair the leaking pipe or, if it is one of the old terracotta systems, have it replaced with a new single-piece PVC one. Then you will at least know that there is little future likelihood of escaping moisture attracting tree roots and inviting any more blockages.
Roots of large trees planted close to house foundations or slabs, especially in areas of clay soil, will siphon large amounts of moisture from the soil under and around the house, causing soil shrinkage and movement, and eventual structural damage. Fortunately areas of sandy loam are significantly less affected by soil movement.
Surface roots can also lift and shift footpaths, driveways – even concrete driveways – and fences. When choosing trees and large shrubs for your garden always consider their ultimate height and, probably more importantly, their spread.
As a general rule most trees have a root spread area similar to the spread of their above ground growth so be sure to plant them sufficiently clear of buildings and other structures so their large supporting roots don’t penetrate beneath the foundations or into the drains.
Avoid planting such trees as willows, poplars, ash and elms and the largest growing eucalypts, unless you have an extra large block and plenty of room for them to spread. They are best left for parks or reserves where they can grow free. No matter how severely you prune and keep any tree or large shrub in check, unless you constrain them in a large container or totally restrict them as a bonsai, almost nothing will keep the roots from doing their thing. In fact they will probably try harder in a bid to encourage top growth.
Holiday or maternity accommodation?
Living, as we do, adjacent to Doctors Gully and virtually surrounded by forest we have done our best to make our garden attractive to the many beautiful local, and transient, native wildlife. As a result, we are continually delighted by the great variety of regular visitors to our bird baths and nectar-bearing shrubs.
We were particularly delighted this week to discover our long-neglected parrot breeding box has acquired a new resident – a ringtail possum who is now ensconced and enjoying the “room service”. Our neighbours also have resident mother and child ringtails in their oak tree, so we can only hope our visitor is maternal and not just another escapee from the CBD ring of steel.
Got a gardening query? Email email@example.com