Hedges are patient. They will grow into the neighbour's yard, block the driveway sightline, and swallow the fence posts — all without saying a word. (Bit passive-aggressive, honestly.)
The answer to when to cut back hedges is this: trim formal hedges twice a year — once in late spring after the first growth flush, once in late summer before the rains return. Flowering hedges get one cut, right after they finish blooming. Conifers like cedar and cypress: once per year, mid-summer at the earliest.
One more thing before we get into timing. If you are doing this between March and August, check for bird nests first. Every time. In BC it is not just good manners — it is the law.
The best time to trim formal hedges
Formal hedges — boxwood, privet, cedar hedging, laurel — want two trims per year. Here is the schedule that works in Surrey and the Lower Mainland.
First cut: late May to early June. The spring growth flush is done. New shoots have toughened up enough to trim cleanly. Wait until the main surge is over — usually by the last week of May — and you will get a finish that holds its shape longer. Cut too early and you are chasing the growth all summer.
Second cut: late August to mid-September. This is the one people skip. It tidies up the summer growth and lets the hedge go into fall looking sharp. Cut now and the surface has time to harden before the November rains arrive. Fresh cuts going into a wet coast winter are asking for trouble.
What not to do: trim in late October or November. I have seen hedges develop canker from a well-meaning November tidy. And avoid cutting in peak summer heat — late July or early August in a dry year — fresh cuts stress the plant when it is already working hard.
Flowering hedges are a different category
Forsythia, mock orange, lilac, rhododendron — these do not play by the same rules.
With flowering hedges, the timing is simple: right after they finish blooming. Miss that window and you are cutting off next year's flower buds. In Surrey, forsythia usually blooms late March to April. Mock orange is June. Lilac is May to June. The rule: wait for the flowers to go, then trim within four to six weeks.
Do not trim them twice a year. One annual cut is enough for most informal flowering hedges. Keep them shaped, not shaved.
Lilac and rhododendron set next year's buds by August. If you are doing any serious reduction, do it in early summer — not fall. Cut after late August and you are removing the following year's flowers.
The bird nesting rule most people miss
This one matters more than the timing.
In BC, under the federal Migratory Birds Convention Act, disturbing an active nest is an offence. That includes cutting the branch or hedge section holding it. Which is exactly what happens when someone fires up a hedge trimmer in June without checking first.
Song sparrows, house sparrows, and robins all nest in hedges. Nesting season runs March through August. A dense laurel or boxwood hedge is prime real estate. (They have no idea how much the trimming inconveniences you. Very on-brand for sparrows.)
The check is simple. Before any cut, walk the hedge and look in. If you see a bird entering the same spot repeatedly, or spot a nest with eggs or young — stop. Leave that section and come back in September.
Nine times out of ten it is not the hedge job that gets homeowners in trouble. It is the timing. An old nest from last season with no activity can be trimmed around. An active one with birds visiting it cannot.
How far back can you cut?
Rule of thumb: do not remove more than one-third of the plant in a single cut.
Deciduous hedges — privet, hawthorn, beech — can take a harder cut and recover. Privet is particularly forgiving. Cut it back hard in late winter, before growth starts, and it will push new growth from the base. That is actually the recommended approach for an overgrown privet that has gotten away from you.
Conifers are different. Cut a Leyland cypress or cedar hedge past the green wood into the brown, and it will not grow back. The brown zone is dead. Most conifers regenerate only from green tissue.
This is the mistake I see most often. A homeowner wants to bring a seven-foot cedar hedge down to five feet. They cut back three feet. Spend the next two years looking at a brown wall. I was called out to a property in Langley last spring where this had happened — the hedge was cut right back to the wood in an attempt to reduce the height. We ended up taking the whole run out. It was not saveable. The rough equivalent of shaving your head and expecting it to fill back in the same shape.
If the hedge has grown significantly past where you want it, reduce it over two to three years. Same end result, without the dead patches. Our pruning and hedge reduction service covers exactly this kind of phased approach.
When to stop doing it yourself
Small, accessible hedges under about five feet — a pair of sharp hand shears and an hour on a Saturday. That is a DIY job. Doing it yourself regularly means the hedge never gets out of hand.
Once the hedge is taller than you can reach comfortably from the ground, that changes.
Rule of thumb: if you need a ladder and a powered trimmer at the same time, give us a call. Homeowners end up in hospital every year from exactly that combination. Hedges are not worth it.
If the hedge has been neglected for more than two or three seasons, it probably needs a professional renovation cut — not just a trim. The one-third rule still applies: you cannot bring a massively overgrown hedge back in one session without damaging it. A professional can assess what is salvageable, set the right schedule, and tell you honestly whether it makes sense to try.
What we tell people honestly: if it is a small, established, accessible hedge you can trim from the ground with shears, there is no reason to call us. Maintenance is the whole point — a little often beats a lot once every three years. We are here for the jobs where things have gotten past that point, or where size and access make DIY a liability.
For what a professional hedge reduction typically runs in Surrey, see our services and pricing page. Crown thinning and hedge reduction starts from $300, depending on size and access.
Hedge timing in Surrey and the Fraser Valley
Surrey's climate is mild and wet. Hedges grow faster here than in drier parts of BC. An established laurel or privet hedge can put on a foot of growth per season without trying.
That growth rate is why twice per year is the right frequency for formal hedges here. Once per year works in drier climates. In the Lower Mainland, a hedge trimmed once in spring already looks overgrown by fall.
The other consideration: aphids and scale insects. A dense, unventilated hedge is exactly what they prefer. A good late-summer trim lets air and light back into the canopy — that is not just aesthetic, it is pest management. The BC Ministry of Agriculture has resources on common hedge pests in the Lower Mainland if you want the details.
If you have conifers along a fence line — cedar, Leyland cypress, Lawson cypress — I would suggest an annual assessment even in years you are not cutting much. Surrey's wet winters are hard on conifer hedges. A professional eye on them before the rain season starts is worth more than an emergency call in February when one of them fails.