Pruning is one of the most important things you can do for a tree's long-term health — but timing matters. Prune at the wrong time of year and you can stress the tree, invite disease, or trigger a flush of weak new growth at exactly the wrong moment.

The good news is that the rules are not complicated once you understand the basics. Here is what Adelaide homeowners need to know about pruning timing.

For most deciduous trees, the best time to prune is late winter to early spring — just before new growth begins. In Adelaide's climate, this typically means July through to early September.

Why this window works so well:

• The tree is dormant, so it is under less stress
• Wounds heal quickly once growth resumes in spring
• Pests and diseases that enter through pruning cuts are less active in cooler weather
• You can clearly see the branch structure without foliage in the way

This timing applies to most common garden trees including ornamental pears, crepe myrtles, roses (technically a shrub but the same principle applies), and many fruit trees.

Evergreen trees — including most Australian natives like eucalypts, acacias, and grevilleas — do not have the same dormant period as deciduous species. For these trees, the rules are slightly different.

Best time: Late autumn to early winter (May–June in Adelaide). This avoids the heat of summer, which stresses freshly pruned trees, and the peak growing season of spring.

Avoid: Pruning eucalypts and other natives in late summer and early autumn. This is when many native species are most susceptible to fungal infections entering through pruning wounds.

If you have fruit trees, pruning timing directly affects your harvest.

Deciduous fruit trees (apples, pears, plums, peaches, nectarines): Prune in winter while dormant — June to August in Adelaide. This encourages strong new fruiting wood and keeps the tree to a manageable size.

Citrus trees (oranges, lemons, limes): Prune lightly after harvest, typically late winter to early spring. Avoid heavy pruning in summer, which can cause sunburn on exposed branches.

Figs: Prune in late winter while fully dormant. Figs bleed sap heavily if pruned when active, which weakens the tree.

Pruning removes foliage that the tree uses to manage its temperature. Cutting during a heatwave — common in Adelaide's summers — exposes the remaining branches to sunburn and puts the tree under additional stress. If a tree needs urgent work in summer, do the minimum necessary and wait for cooler conditions for any non-essential pruning.

When a tree is pushing out new growth in spring, its energy reserves are at their lowest. Heavy pruning at this time removes the new growth the tree has invested energy in producing. Light shaping is fine, but save major structural work for the dormant season.

Some species — particularly stone fruits like cherries and plums — are susceptible to fungal diseases like silver leaf and brown rot that enter through fresh pruning cuts. Avoid pruning these trees in wet weather when fungal spores are most active.

There is one exception to all of the above: safety pruning can and should happen whenever it is needed.

If a branch is dead, damaged, or poses an immediate risk to your home, family, or neighbours, do not wait for the ideal pruning window. Dead branches can fall without warning, and a branch overhanging a roof or powerline is a risk regardless of the season.

For safety-related pruning, call a licensed arborist who can assess the risk and carry out the work safely.

Trees growing into powerlines are a special case. In South Australia, SA Power Networks has specific requirements around vegetation near powerlines, and in some cases they will carry out clearance work themselves.

If you have a tree growing into or near powerlines, contact a licensed arborist before attempting any work yourself. Working near powerlines is dangerous and requires specific training and equipment.

Regardless of the season, these are signs that a tree needs attention sooner rather than later:

• Dead or dying branches — these can fall at any time
• Branches rubbing against your roof, gutters, or fence
• Canopy so dense it is blocking light to your garden or home
• Branches crossing and rubbing against each other (causes wounds that invite disease)
• Suckers or water shoots growing from the base or main trunk
• Branches growing toward powerlines

For small trees and light shaping, a competent homeowner with the right tools can do a reasonable job. But for anything involving:

• Trees over 4–5 metres
• Work near powerlines
• Structural pruning of mature trees
• Trees close to buildings or fences

...you should use a licensed arborist. Incorrect pruning of large trees can cause structural failure, introduce disease, or create hazards that are not immediately obvious.

At Landmark Outdoor Projects, our arborists prune to Australian Standard AS4373 — the industry benchmark for pruning practices. We assess each tree individually and recommend the right approach for its species, age, and condition.

Call 0410 088 411 or get a free quote online for tree pruning across Adelaide.

When in doubt, late winter is the safest default for most Adelaide trees. And if you are unsure whether a tree needs pruning or how much to take off, a quick assessment from a licensed arborist is always worth it.