Posted on: 11 April 2016
It's common knowledge that the Australian ecosystem suffers great damage at the hands of invasive species, and exotic flora and fauna can cause serious environmental damage if allowed to grow on your land. One of the most damaging invasive species we have is an unassuming and rather attractive tree called the honey locust, but despite the havoc it can wreak it is often allowed to grow freely, and is even cultivated for fodder by some. But what is it about this tree that makes it such a pest?
What is honey locust?
The honey locust tree (Gleditsia triacanthos) originally hails all the way from central North America, but has grown in Australia for many years. The tree is renowned for its ability to grow in conditions too adverse for other trees, such as highly salty or acidic soils, and can resist droughts with its long and complicated network of roots. As such, honey locusts have been used in previous years to control land erosion caused by over-farming. In addition, the honey locust is prized for its delicate cream blossoms and the vibrant colours of its leaves throughout the seasons, and various cultivars have been bred for their ornamental value. As a result, the honey locust now grows across wide areas of agricultural Australia.
Why should I remove my honey locusts?
As useful as this hardy tree can be, it has a number of highly undesirable properties which make removal of honey locusts growing on your land a pressing concern:
- Environmental damage -- Honey locusts tend to grow together in dense thickets, and their rapid growth means that a single tree can seed and sprout a dense thicket in a matter of a few years. These thickets starve native plants of light and oxygen with their dense growth, and cause chemical changes in the soil that can make growing plants or crops difficult even after the trees are removed. They are also thick and dangerous enough to prevent the passage of animals, and can prevent wildlife from reaching drinking water if allowed to grow by rivers and lakes.
- Thorns -- The honey locust is sometimes colloquially known as the 'thorny locust', and for good reason. Practically every inch of a honey locust's branches is protected by long, viciously sharp thorns, which can pose a risk to people and livestock if the trees are allowed to grow unchecked. When fallen, these thorns are tough enough to puncture vehicle tyres.
- Structural damage -- The roots of a honey locust grow deep and strong, and can do serious damage to basements and subterranean pipes. Honey locusts also grow remarkably quickly, and in urban areas they can quickly grow tall enough to interfere with power cables and telegraph wires.
- Competition -- Because honey locusts grow so quickly and often grow in poor soil, they are extremely efficient at rapid draining moisture and nutrients from the soil, This makes them dangerous to grow near crops, as the wide-ranging roots can cause crop failure over a surprisingly large area.
How should I have my honey locusts removed?
Honey locusts are tenacious trees, and their thorns can make them a particular challenge to remove. However, there are a couple of ways to safely and thoroughly remove honey locusts:
- Cutting -- Honey locusts are fast-growing trees with relatively short lifespans, and if they are repeatedly felled while young they can become exhausted to the point of death by attempts to regrow. This method will take at least a few years to be successful, and once weakened the stumps will need to be thoroughly uprooted to prevent roots from sprouting. Hiring professional tree surgeons is the easiest way to go about this, and involves much less thorn impalement on your part. Honey locust wood also happens to make excellent firewood.
- Herbicides -- When applied to a hole drilled in the stump of a recently felled honey locust, the herbicides picloram and triclopyr will quickly and efficiently kill the tree. These herbicides can also be painted onto the bark at the base of young trees to kill them, although this is largely ineffective on older trees. Have your herbicides applied professionally to minimise the risk of accidental contamination of groundwater, and do not use herbicides on trees growing by bodies of water. Pelleted herbicides are also discouraged, as they can leech into the soil and damage beneficial native flora.