Whitehorse City Council

Caring For Street Trees

All residents of Whitehorse can contribute to the establishment and care of new street tree plantings. The following tips are provided to assist residents in helping Council to manage the health of the municipality’s street tree population. 

Watering

Council waters new street trees on a weekly basis over summer. Additional watering is often required during extended hot, dry periods. A bucket of water poured into the planting tube once or twice a week during summer will help to maintain the tree’s health and vigour. 

Too much water can be as detrimental to a tree’s health as lack of water. The best method of checking for soil moisture levels is to feel the soil just below the layer of mulch. If the soil is dry, the tree should be watered. 


 

Mulch

The base of all new trees planted in Whitehorse is covered with a thin layer of organic material (mulch) at the time of planting. Ideally, the layer of mulch should remain no more than 10 centimetres deep. Porous materials such as wood chips are used. Grass clippings are not a desirable mulching material as they can promote weed growth, and the high nitrogen content may cause stress to young trees. Mulch helps to retain water and assists in the suppression of weeds and other vigorous competitors such as grasses.  

It is important that mulch is not placed flush against the trunk of a tree as this can cause the base of the tree to rot. A three to five centimetre gap between the trunk and the layer of mulch should be maintained. Additionally, mulch should not be deeply mounded around a tree as this restricts the passage of oxygen to the tree’s root system.


 

Protecting Tree Roots From Soil Compaction

Soil compaction can prevent oxygen from reaching tree roots. It can be caused when cars are parked too close to a tree, or heavy machinery or materials are stored at the base of a tree. 

Equipment and materials should be not be stored either beneath the canopy of a street tree, or near the mulched area around a tree. 


 

Trunk Protection

Mechanical damage to a tree trunk (frequently caused by lawn mowers or line trimmers) can cause serious damage – especially to young trees. A large trunk wound on a small tree may permanently affect the health of the specimen. When maintaining nature strips care should be taken to avoid contact with the trunk of the tree. 


 

Stakes

Not all newly planted trees require staking, however, some trees need support in their establishment phase. Staking trees may also provide an element of protection against mower damage or vandalism. Stakes should be removed once the tree is established or they can damage the tree. Ideally, stakes should be removed after one-two years to avoid the trees becoming dependent upon them, and to avoid them permanently enveloping the tree. 

Two stakes are usually used per tree and they should be positioned well away from the trunk to avoid root system damage. The stakes should be attached to the tree with a flexible tie. Residents can greatly assist Council by reporting any damage, loss or overdue removal of tree stakes. 


 

Tree Monitoring

Council appreciates resident input in managing our 80,000 street trees. Residents can make a valuable contribution to the community by caring for the nature strip street trees and are requested to report any acts of vandalism or issues of street tree health.