Tree info

Most people ring an arborist because something has changed. A crack, a lean, a limb that came down, leaves that are not right for the time of year. The useful question is a simple one: is this tree a problem, and if it is, what is the smallest thing that fixes it?

What Ben looks at

• How the tree is built. The main unions and forks, whether there is included bark trapped in them, and where the weight goes when the wind gets up.
• Defects. Cracks, cavities, decay pockets, old failure points, and damage left behind by bad pruning years ago.
• Deadwood. How much there is, how big it is, and what is sitting underneath it.
• The canopy. Density, dieback, stress growth, leaf colour and size against what that species should look like at this time of year.
• Pests and disease. Elm leaf beetle, borers, fungal brackets, and the signs of rot at the base.
• The ground. Compaction, recent digging, paving, changed soil levels, drainage. This is where most mysteries get solved.

Usually the problem is at ground level

A mature tree that starts thinning out for no obvious reason has very often had something happen to its roots. A build next door. A new driveway. Soil piled over the root zone during landscaping. A trench for a pipe that cut through the wrong side.

The catch is timing. The canopy usually does not show it for a year or two, so by the time anyone notices, nobody connects it to the excavator that was there last spring. Knowing to look down instead of up is most of the job.

Leaning trees

A lean on its own is not a problem. Plenty of trees lean their whole lives and are perfectly sound, particularly if they grew that way reaching for light. What matters is whether the lean is new, whether the soil is cracked or lifting on the opposite side of the trunk, and whether the root plate is moving. Those are the things worth checking.

What tends to go wrong in Canberra

Elm leaf beetle is everywhere in the older suburbs and hammers elm canopies every summer. Most trees cope, but the repeated stress builds deadwood, which is the part that actually matters when it is hanging over a driveway.

Included bark unions in the big 1970s eucalypts. Two stems grown tight together with bark trapped between them and no real wood connection. They split, usually in wind, usually taking half the tree.

Drought stress followed by a wet year. Canberra swings hard between the two, and trees shed limbs on the way through.

Straight answers, including “it is fine”

Sometimes the honest answer is that the tree is healthy, the lean is old and stable, and nothing needs doing. Ben will tell you that when it is true. An arborist who finds expensive work on every tree he looks at is not really looking.

And where something does need doing, it is very often a deadwood clean-out or a reduction rather than a removal.

If your tree needs ACT approval

People tell us the ACT Government site is hard to navigate, so here is the direct link. The form you want is a tree activity application, and it is lodged online through the Urban Forest Management System.