Some guiding principles

I often visit gardens in the Southern Tablelands where managing wind is top priority. Windbreaks are the best long term strategy for doing this.

Wind strips moisture from leaves and soil and quickly dehydrates plants. It can break branches, uproot young trees and even blow over established trees.

A well-designed windbreak can slow wind speeds up to 80%. A windbreak’s protective zone extends across the landscape up to 20 times the height of the trees. That means that the bigger the area you’re trying to protect, the taller your trees need to be.

If you’re planning a windbreak the first step is to observe which direction your wind comes from. In the Southern Tablelands we usually need to protect from the west and north-west winds, as well as cold southerlies.

Features of an effective windbreak

Orientation: Position the windbreak perpendicular to the direction of the prevailing wind.
Depth: Aim for a depth of 3, 5 or 6 rows of trees and shrubs to effectively filter airflow. If you’ve got more space, plant a grove.
Plant along contours: Ideally plant along contours to create a softer, more organic look. This will also help with water retention.

Source: Sustainable Farms, Australian National University

Why is permeability important in a windbreak?

The most successful windbreaks filter and slow the wind and allow some wind through. If you try to stop the wind completely (for example with a high wall or dense pine tree plantings) you will create turbulence. Turbulence is uncomfortable for people and stock and it damages gardens.

What to plant?

Mixed native plants create the best windbreaks. Source them as tube stock from a local supplier. Plants grown locally will be best adapted to local climate and soils will have the best survival rates.

Remember that the species you choose will depend on their position in the landscape. Plantings for ridgelines will be different to plantings for low-lying areas.

If your planting also aims to screen noise then plants with dense foliage will be a good choice.

How many plants?

Plant trees and shrubs 3 - 4m apart and allow 3 - 4m between rows.

The value of a whole-property plan

A property plan will include a site analysis which identifies prevailing wind direction, higher ridges, low lying areas and existing plant communities. This is a great starting point for your windbreak design and species selection and it will help connect existing patches of remnant vegetation.