Selecting the right tree

Selecting a tree for your garden can be an exciting and daunting task.

For most, the first consideration is what type of tree will best suit your garden style. But when it comes to tree selection, it’s just as important to consider how your tree or shrub will look below ground.

Tree roots can creep into underground wastewater pipes and cause damage and even blockages. While falling leaves can block up stormwater drains. So when choosing a tree, here are a few things to consider to ensure they don’t cause issues at your property. 

What waterwise trees can I plant?

Use our handy waterwise tree list below to understand which trees and shrubs will suit your property, and the amount of maintenance they require. There are a range of sizes, as well as both WA natives and exotic trees and shrubs to select from.

Waterwise trees tend to have non-invasive root systems which reduces the risk of damage to underground assets. For example, with deciduous trees, you will need to collect fallen leaves to keep them out of stormwater drains.

Our waterwise tree list also includes the amount of maintenance each tree requires. For example with deciduous trees, you will need to collect fallen leaves to keep them out of stormwater drains.

Once established, waterwise trees only need to be watered once or twice a week. Many of these trees will flourish over the summer months with minimal watering.

Where can I plant waterwise trees?

Prior to planting a tree anywhere on your property, you must contact Before You Dig Australia to make sure underground pipes won’t be damaged or interfered with.

If you want a tree on your verge, be sure to contact your local council for the relevant guidelines. This is an essential step as vital public assets such as water, electrical, gas and telecommunication infrastructure are often located underneath a verge.

All verge trees must be planted at least 2.7 metres from the property boundary line and a minimum of 0.5 meters from water pipes.

What if I don't select the right tree?

Trees and shrubs are an important part of our built environment. But, if they’re not carefully chosen, they may cause avoidable damage to infrastructure.

Trees and shrubs rely on their roots to find moisture and nutrients. And your property’s wastewater pipes can be an attractive moisture source. All it takes is for the root to sneak into a crack in the pipe. Once inside the pipe, the root can grow quickly, causing a reduction in water flow or even a complete blockage. Often, complete sections of pipe need to be replaced which can be expensive.

Waterwise tree list

The following list is intended as a guide to assist you with selecting the right trees or shrubs for your garden. Each tree has been scored on a water rating and level of root invasiveness by specialist tree consultants.

Water rating

• 0 drop - once established will require no supplementary watering.
• 1 drop - requires watering once a week once established.
• 2 drop - requires watering twice a week once established.

Root invasiveness

• Low - the species doesn’t display vigorous root development and isn't commonly associated with damage to pipes.
• Moderate - the species may cause some damage to pipes. Tree species are more likely to originate in more temperate climates than the Perth region, and have a higher requirement for water.
• High - these species have vigorous root development. Trees within this category are generally not recommended for planting near pipes. They may also be included within a list of trees considered unsuitable for verge or urban garden planting.

Flowering type

• Showy / ornamental - trees have large flowers or voluminous displays of flowers.
• Inconspicuous / small - trees have flowers, however these may be small, sparse, or not ornamental
• No flowers - tree does not have flowers, or in the case of figs are cryptic

Advice for local government

All trees must be planted in accordance with the Utilities Providers Code of Practice Guide, which states that trees must be planted 2.7m from the property boundary line and minimum of 0.5m from water assets.

For local government planting medium and large street trees, please contact us regarding your annual tree planting plans. We can help to ensure the longevity of the tree and minimise the possibility of interruption to local water supplies. Any damage or interference with a Water Corporation underground asset may result in a fine.

Download our Selecting the right tree information sheet.