When to Prune on Sydney's North Shore: A Month-by-Month Guide

A crisply clipped low hedge and lawn in front of a tall formal hedge in a garden on Sydney's North Shore

Almost every "my plant never flowers" conversation we have on the North Shore ends in the same place: it was pruned at the wrong time of year. The cut itself was usually fine. It simply happened after the plant had set the buds it was going to open, so a season's flowering went into the green bin.

The general rule is easy to remember. Prune flowering plants immediately after they finish flowering. That gives the plant the longest possible run of growing weather to build next season's buds, and it means you are never cutting off buds that have already formed. Almost everything below is an application of that one rule to the species that actually dominate gardens here.

Winter: June to August

Winter is the structural season. Deciduous plants are dormant, their framework is visible without foliage in the way, and the cuts you make now shape the whole of next year.

Roses. Mid to late July is the window in Sydney. You will hear the Anzac Day rule repeated, but that timing suits colder districts; on the North Shore late April is too early and the bush pushes soft growth into the cold. Cut back by roughly a third to a half, open the centre, and remove anything dead, damaged or crossing.
Deciduous fruit trees. Apples, pears and plums are pruned while dormant. Apricots and cherries are the exception worth knowing: prune those in summer after harvest instead, because winter cuts in wet weather invite silver leaf and bacterial canker.
Hydrangeas. Cut spent flower stems back to a pair of fat buds. The thin, whippy stems that never flowered can come out at the base.
Wisteria and deciduous climbers. Shorten the long summer whips back to a few buds to build flowering spurs.

What not to touch in winter: frangipani, murraya, gardenia and most tender subtropicals. Cold, wet cuts on those plants heal slowly and often rot back further than you cut.

A bare deciduous tree in winter, its branch structure fully visible against the sky — Winter is the only time you can see what you are actually cutting. With the leaves gone, crossing limbs and a crowded centre are obvious, which is why structural work on deciduous trees belongs in June and July.

Early spring: September to October

This is the busiest pruning month of the year in a well-kept North Shore garden, because it is when the formal work starts and when the winter-flowering plants finish.

Buxus, and the first hedge cut of the season. The spring flush is the strongest of the year, so the September cut sets the shape the hedge holds through summer. Cut to a slight batter, wider at the base than the top, so light reaches the bottom and the hedge does not go bare-legged.
Japonica camellias. Once the last flower drops, thin the interior and shorten any growth that has broken the shape. Camellias tolerate more pruning than people expect, including renovation back into older wood if a plant has become a hollow shell.
Citrus. After harvest and once the cold has passed. Keep it light, take out the water shoots and anything dragging on the ground, and leave enough canopy that the limbs are not sunburnt.
Murraya and photinia. Both respond to a shaping cut as the weather warms, and both flush hard afterwards, which is the point with photinia.

Clipped buxus hedging with a sharp square corner, beside azaleas coming into flower and a gravel path — The September cut is the one that matters on buxus. Note the slight batter on the face, wider at the base than the top, which keeps light reaching the bottom so the hedge never goes bare-legged.

Summer: December to February

Summer pruning is maintenance rather than reshaping. Growth is fast, so hedges are cut to hold the line rather than to change it.

Formal hedges. A December or January trim keeps buxus, murraya and lilly pilly crisp through the entertaining season. Cut in the cool of the morning and never during a heatwave, when freshly exposed inner foliage scorches within a day.
Stone fruit, after harvest. Summer is the safer window for apricots and cherries, and summer cuts also restrain the size of a tree more effectively than winter cuts, which stimulate vigorous regrowth.
Natives. Grevilleas, westringia and callistemon are tip pruned lightly after each flush. The rule that matters is not to cut back into bare old wood on grevilleas and leptospermum, because they often will not reshoot from it.
Agapanthus. Deadhead before the seed heads dry. This is presentation on any block, but near a Ku-ring-gai bushland reserve it is a genuine weed control measure.

Coral-red new growth flushing along the top of a clipped photinia hedge — Photinia is the one hedge where the regrowth is the display. Each correctly timed cut is followed by this coral flush, which is why it is trimmed more often than a hedge kept purely for its green.

Autumn: March to May

Autumn is the tidy-up, and the season with the most timing traps.

Sasanqua camellias. They carry the autumn display, so they are pruned as the flowering tails off in late autumn, not before it.
Gardenias. Prune after the last flush of flowers, while there is still warmth in the soil for recovery.
A final hedge cut. One shaping cut in March or early April carries a formal hedge through winter cleanly. Leave it much later and the regrowth is too soft going into the cold.
Hold off on hard cuts. Anything tender is best left alone now. A plant heading into winter with fresh wounds and soft new growth is a plant that will look sorry by August.

The one job worth checking before you start

Tree work is regulated here. Ku-ring-gai Council controls pruning and removal of trees over a certain size, and the area contains remnants of Blue Gum High Forest and Sydney Turpentine-Ironbark Forest, both endangered ecological communities carrying additional protections. There are exemptions for smaller trees, dead wood and some species, but they are specific enough that guessing is a poor strategy. If a job involves anything more than light shaping of a small ornamental, confirm the position with Council first, or have it assessed as part of a quote. Our tree pruning work covers small trees, ornamentals, fruit trees and hedges, and we will tell you plainly when a job needs a consulting arborist or Council approval instead.

If you would rather not track all this

Getting the timing right across a mixed garden means keeping a calendar for a dozen different species at once, which is precisely what a maintenance program is for. Our garden maintenance plans schedule each cut in its correct window, so the camellias are pruned after flowering and the hedges are shaped before the flush rather than during it. If you want a considered look at the whole garden instead, our horticulture services cover seasonal care programs built around what you actually have growing.

Frequently asked questions

When should I prune camellias on the North Shore?

It depends on the type. Sasanqua camellias flower through autumn, so prune them in late autumn or early winter once the last flowers drop. Japonicas flower from mid winter into spring, so they are pruned in spring after flowering finishes. Pruning either one before it flowers simply removes the buds you were waiting for.

Do I need council approval to prune a tree in Ku-ring-gai?

Often, yes. Ku-ring-gai Council regulates pruning and removal of trees above a certain size, and parts of the area contain endangered forest communities with additional protections. Exemptions exist for small trees, some species and dead material, but the thresholds are specific. Check with Council before any significant tree work, or ask us to assess it as part of a quote.

Is there a time of year when I should not prune at all?

Avoid hard pruning during a heatwave, when the sudden exposure of inner foliage and bark leads to scorch. Avoid pruning frost-tender plants like murraya and frangipani late in autumn, since the soft regrowth is what the cold damages. It is also worth checking hedges for active nests in spring, as native birds are protected.

Keep reading

More on local conditions: shade-tolerant plants for a North Shore canopy and working with Ku-ring-gai soils.