Other Services

Stem Injection

Colac Trees offers stem injection services to eradicate parasites from your trees. This method involves injecting environmentally friendly insecticides or fungicides directly into the tree trunk. The treatment is then transported through the tree to the leaves, where it kills the pest. 


The most common treatment we offer is Elm Leaf Beetle Treatment Programmes, which helps protect your beautiful trees. From the months of October through mid-March infestations can grow in your trees. We understand this can be quite distressing, especially if the tree is a major feature of your garden or even in parks & playgrounds. These beetles place holes in the leaves of your trees, which then develop into longer lace-type holes this is caused by the beetle's larvae. These larvae and cause a lot of damage in a very short time. If left untreated, they can defoliate your entire tree stripping it bare. At the first sign of beetle infestation, call Colac Trees to enquire about our range of stem injection treatments to protect your trees from parasites. 

  • Trees with Elm Leaf Beetle — Colac, VIC — Colac Trees

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Some interesting facts worth knowing about the Elm Leaf Beetle 

  • The Elm Leaf Beetle is approximately 4-6mm long. 
  • It is green and brown colour with two stripes.
  • The beetle can defoliate a tree in a week.
  • As elm trees come onto the leaf with the arrival of spring the adult beetle emerges from its winter hibernation.
  • These beetles feed on the leaves in the canopy of the tree where they lay yellow eggs on the underside of the leaves.
  • The eggs then hatch as black and yellow caterpillars or larvae.
  • The larvae feed on the soft green underside of the leaf.
  • These larvae can then crawl down the trunk of the tree & pupate in bark cracks or around the base of the tree.
  • The pupate emerge as adult beetles and return to the foliage thus continuing the cycle its live and the destruction of your trees.

Their Average Life cycle

  • March – September: Hibernation
  • October: Beetle emerges
  • November: Eggs laid
  • December: Larvae
  • January: Pupae
  • February: New adults

Common signs of Elm Leaf Beetle:

  • Symptoms can first start to appear in early summer with leaf damage from October through to February.
  • Discolouration can be another sign around December to February.
  • You may see large clumps of leaves from your tree turn yellow & start to wilt.
  • Small hole punch sized holes in the leaves usually caused by the adult beetles
  • The skeleton like appearance of the leaves is caused by larvae
  • Trees might also display a mixture of healthy as well diseased foliage and shoots.
  • These affected shoots will start to die back from the tip

Our Prevention Advice

  • Keep elm trees free of dead limbs and suckers.
  • Water well during drought times causing less stress to the trees give them better resistance.
  • Keep elm trees healthy by fertilising them regular best time is in late winter using slow-release fertiliser.
  • Encourage good soil conditions by covering the root zone with mulch.

Our Treatment 

It’s important to understand that while the Elm Leaf Beetle can never be fully eradicated it can be managed effectively.

  • Early detection & early treatment is essential in not only determining the size of the problem that need to be treated, but also aids in a faster recovery time for your tree, getting in back to healthy green foliage state. Our treatment method ids trunk injection with chemical Imidacloprid, which is considered to be the most effective and most environmentally sound option. Insecticide is injected directly into the trunk of the tree. The tree transports the chemical up into the leaves of the tree where it kills the beetles. However, tree trunks should be greater than 200mm in diameter. The elm beetles only need to ingest a small amount of leaf material for the chemical to kill them.
  • Trunk injection is safe around children, pets and riparian situations like waterways, oceans & lakes.
  • Canopy spraying known as Foliar sprays can be used on young trees towards the end of October. This method in older trees is not used due to the sheer size of larger elm trees. Foliar sprays also need to be applied twice annually.
  • Some non-chemical control treatment like banding around the trees truck is a safe non-chemical control that sometimes works to trap larvae that migrate down the trunk. Best times are between December to early February. Also, adhesive tape can be wrapped around the trunk in a strip about 20cm wide, with the sticky side facing out. This can help to break the Elm Leaf Beetle lifecycle. These bands need to be applied before the larvae start to crawl down the trunk, which can vary depending on the weather pattern each season, so close monitoring is essential. Banding treatments may need to be reapplied several times each season if beetle numbers are high. These methods will not reduce damage in the initial year of application but should reduce beetle numbers and damage in subsequent years. This method, while environmentally safe, may not be effective against heavy infestations. Colac Trees can inspect your trees and assess the situation for you and advice on the best treatment plans for your tree and environment.

What is the soil injection method & why we don't endorse this method

Soil injection treatment involves injecting the soil under the tree using a dripline this can be applied to trees of any size in diameter. Soil injection requires up to 100 L of water for each tree and is not recommended when soil moisture is low. The movement of the chemical is slower so therefore this treatment method needs to be carried out around 6-8 weeks before the beetles emerge from their hibernation. Soil injection is detrimental to soil flora and fauna, including earthworms and mycorrhiza. Applications near creeks and rivers or near food gardens pose particular risks for invertebrates and human health as it will kill everything in the soil.

 

Timing – The best time to treat elm trees is just as they come into leaf. Stem injection can be done any time but ideally before the beetles have laid their eggs or just after the eggs hatch.

Common questions we get asked :

What is eating my elm leaves?

The elm leaf beetle, as small as these pests are they can literally damage your trees entire foliage in a week if you leave your elm tree untreated. The elm leaf beetles currently pose the greatest threat to the health & wellbeing of Australia’s elm tree population. At their peak these elm leaf eating beetle, cause the most damage to elm trees during the larval stages of the insect's life cycle.

Why is my elm tree dying?

The most devastating elm tree diseases are Dutch elm disease and elm phloem necrosis. Dutch elm disease is caused by a fungus spread by elm bark beetles. The microscopic organism that causes elm phloem disease is spread by white-banded leafhopper

How do you treat elm beetles?

The Elm Leaf Beetle will never be fully eradicated, but it can be managed. Early treatment is important. The best treatment known today is Tree Stem Injection for the (Elm Leaf Beetle). Trunk injection with Imidacloprid is considered to be the most effective and environmentally sound option. The insecticide is injected directly into the trunk of the tree.

Possum & Koala Guard Installation

Colac Trees offer possum and koala guard installation, which is a preventative measure to protect trees from possum and koala damage. The possum and koala guards are installed around the trunk of the tree and are a safe and humane way to stop animals such as possums and koalas from causing damage to your trees and may also aid in preventing cats from predating on native bird nests or other native animals. Possum and koala guard installation is a simple and effective way to help protect trees from possum and koala damage.

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  • Tree Bracing and Cabling — Colac, VIC — Colac Trees

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Tree Bracing & Cabling

Tree bracing and cancelling creates a safer environment and strengthen the structure of your tree. Trees may lose their structural integrity due to defects in the tree due to overweight or oversized branches, tree limbs affected by disease or pests or damage from severe storms. Cabling and Bracing your tree adds additional support to the tree’s structure, reducing any risk of collapse and avoiding the total removal of the tree. 


The tree cable bracing system we can offer involves installing special steel cables and braces to any at-risk trees, providing a non-invasive system incorporating tree growth loops, allowing the tree to gain natural strength whilst preventing any unnecessary damage to the tree layer it grows. Our qualified Arborists can also utilise other tree support systems such as bracing, guying and propping to manage risks and prolong life of your trees.


As experienced arborists, it is always our goal to strengthen and stabilise the limbs and branches of your trees to ensure they are more wind and weather-resistant, which aids in the overall healthcare & lifespan of the trees. 

Mulch & Firewood Supplies

The Colac Trees team often has a surplus of mulch and salvaged firewood supplies from works carried out around the Colac and Otway areas.

This includes mulch, which is the by-product of the trees and leaves we cut down or remove that have been through our wood chipper. Our mulch is mainly supplied 'green', and we recommend you let it compost down and age for a few months prior to use. 

We do not buy or cut logs for firewood, this is also a by-product of the trees we remove locally, making our firewood the most sustainable on the market.

As stocks can be limited, call the team today for availability. 


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Hollowhog  / Habitats for Wildlife

Colac Trees offers habitat creation services for our native wildlife in existing trees. We use the Hollowhog wood carving tool which has been specifically designed to create habitat for hollow dependent wildlife.

The Hollowhog efficiently and safely creates large internal cavities through small entry holes in both living and dead wood. No other damage to the tree’s cambium (living tissue) occurs through the carving process meaning that there is little disruption to a tree’s growth.


For more information visit the Hollowhog Official Website. Colac Trees is also able to provide a demonstration on how we create and install these habitats with the Hollowhog tool.

We also offer the following services:

  • Tree Risk Assessments & Management Plans
  • Palm tree clean-up, maintenance and removal
  • Wood milling services


For further information on these services, please call us directly.

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