Weeping Willow Tree

Q: After some anecdotal advice I have planted a 3 meter high Weeping Willow 3 meters from the edge of a heavily lined lake. The lining of the lake is industrial grade, i.e. approx 25 microns thick.

The roots of the tree will be constantly wet and receiving a constant trickle from underground reticulation. I'm told that the hair like growing roots at the ends of the roots will eventually hit the liner and turn away.

Are you able to confirm this point? Obviously I'm hoping that I do not need to transplant.

A: A micron is one-millionth of a meter, so if I've done my metric-to-English conversion correctly, 25 microns is only about 0.00008484 of an inch. To me, the liner doesn't seem to be thick enough to detour any roots.

The roots may grow alongside it, but as the roots thicken in diameter they may exert enough pressure on the liner to distort, break or tear it.

I suggest moving the tree further away, but, being a willow, it will probably find its way to the liner in short order.

My recommendation is to contact a local arborist knowledgeable in these matters and ask his or her advice. I know there are many members of the International Society of Arboriculture in Australia, so you should be able to find someone who can help you.