Seasonal guide · New Brunswick
New Brunswick Lawn Season: When to Start Mowing and When to Stop
IllustrationIn New Brunswick, most lawns need their first cut in early to mid May. The last cut usually lands in late October or early November. Snow is normally gone by the end of April in Fredericton, Moncton and Saint John. Grass slows down through October and stops once daytime highs stay under 10 C (50 F). A frost in late September doesn't end the season.
When does lawn season start in New Brunswick?
It starts when the soil warms up, not when the snow melts. The Guelph Turfgrass Institute says cool-season grass starts to grow when the soil reaches 4.5 to 7 C (40 to 45 F).
Here's what a normal spring looks like at the three main airports:
- Snow on the ground at the end of April: 0 cm in Fredericton, 1 cm in Moncton and 0 cm in Saint John.
- Normal April high: 10.0 C in Fredericton and 8.5 C in both Moncton and Saint John.
- Normal May high: 17.6 C in Fredericton, 16.0 C in Moncton and 15.0 C in Saint John.
So April is mostly cleanup weather. The soil is cold and wet, and the grass barely moves. By May, highs climb fast and the lawn wakes up. Most yards are ready for a first cut in early to mid May.
Fredericton tends to green up first. It has the warmest spring of the three. Saint John and Moncton often run a little behind.
Should you rake as soon as the snow is gone?
Not right away. Walking on soggy grass leaves ruts and pulls up crowns. Wait until the ground is firm under your feet.
The City of Fredericton gives one more reason to wait. It says to hold off on cleanup until it's consistently above 10 C. Many pollinators spend the winter in dead plant material. Our spring and fall cleanup page covers what a crew clears on that first visit.
How do Fredericton, Moncton and Saint John compare?
New Brunswick isn't one climate. Inland Fredericton has hotter summers. Saint John, on the Bay of Fundy, stays cool. Moncton sits in between, but gets its last spring frost latest.
| Airport station | Last spring frost | First fall frost | Frost-free days | Normal July high |
|---|---|---|---|---|
| Fredericton | about May 17 | about Sept 25 | 130 | 25.5 C |
| Moncton | May 22 | Oct 4 | 134 | 24.7 C |
| Saint John | about May 16 | about Oct 2 | 138 | 22.6 C |
These are Environment and Climate Change Canada averages from 1981 to 2010. They're averages, so any one year can be early or late. In Moncton, about 1 year in 10 still gets frost on or after June 8.
A late frost won't hurt a lawn much. It mostly matters for tender plants in your beds. But it does tell you the grass will grow slowly until the nights warm up.
What does the middle of the season look like?
From late May to the end of June, grass grows at its fastest. This is when weekly mowing pays off. Skip a week and you'll be cutting off too much at once.
Health Canada says grass cut at 6 to 8 cm (2.5 to 3 inches) grows deeper roots and gets thicker. It also says to sharpen your blade in spring and keep it sharp. A clean cut heals faster than a torn one.
Saint John's cooler July is easier on a lawn. Fredericton's hotter summer can slow growth in a dry spell. If your grass goes brown in the heat, read our post on dormant brown lawns before you worry.
Our partner crews mow at a steady height all season on our lawn mowing visits, with trimming along walks and fences.
Does the first frost mean you can stop mowing?
No. This trips up a lot of people in Fredericton. The average first frost there comes about September 25. But the grass keeps growing for weeks after that.
Iowa State University Extension says to keep mowing until the grass stops growing. It says cool-season grass stops when daytime highs stay below 10 C (50 F).
Look at the normal October highs:
- Fredericton: 13.2 C
- Moncton: 12.8 C
- Saint John: 12.3 C
That's still above 10 C, so the lawn is still growing, just slower. Our post on mowing after a frost explains how to cut safely on frosty mornings. The short version: wait until the frost melts off.
When is the last cut in New Brunswick?
For most yards, it falls in late October or early November. By November, the normal high drops to about 6 C in all three cities:
- Fredericton: 6.0 C
- Moncton: 6.1 C
- Saint John: 6.4 C
Once highs stay that low, the grass stops growing. Watch the weather, not the calendar. A warm October can push your last cut a week later.
For the last cut, stay in that 6 to 8 cm range. Don't scalp it short and don't leave it long and floppy under the snow. Our guide to the last mow of the season walks through it step by step.
When should you do fall cleanup in each city?
Get the leaves off before the first lasting snow. Wet leaves left all winter can mat down and smother grass. Each city handles leaves its own way.
Fredericton
Yard waste goes to the curb once a month, from April to November, in the last full week of the month. The 2026 fall weeks are October 26 to 30 and November 16 to 20. Leaves must be in compostable paper bags. Plastic bags and loose leaves are not picked up. See our Fredericton leaf and yard waste guide for the full rules.
Moncton
Grass clippings and leaves go in the green organics bag, and that's picked up every week. Orange and paper bags are also fine for leaves and yard waste. Our Moncton fall yard waste post has more.
Saint John
Leaves and yard waste go in your green compost cart. Extra leaves go in brown paper leaf bags. Plastic bags aren't accepted.
New Brunswick also banned more than 240 lawn care pesticide products back in 2009. Our partner crews don't spray, so cleanup is rakes, blowers and bags only.
Do New Brunswick cities limit grass height?
Only one of the three big cities does:
- Moncton: Tall Grasses By-law Z-1418 says grass and weeds can't be over 20 cm (about 8 inches). That includes the strip of street in front of or next to your land.
- Fredericton: the City says its unsightly premises by-law has no grass height limit for private property.
- Saint John: the unsightly premises by-law, M-30, lists junk and derelict vehicles, but no grass height. Our Saint John long grass post goes deeper.
In Moncton, a fast stretch in late May or June can push a skipped lawn toward that 20 cm mark. That's one more reason to keep a steady schedule then.
Who can handle the season for you?
Golden Oak Lawn Care matches you with a vetted, insured local crew in Fredericton, Moncton or Saint John. They do the work. We stand behind it with the Golden Oak Guarantee.
With the Worry-Free Lawn Season, the same crew comes every visit from the first cut in May to the last one in the fall. Your crew texts a photo after every cut. The season is paid up front, and you can pause by text when you're away. Your first cut is free when you book the season.
See your city page for local details: Fredericton, Moncton or Saint John. Or start at our New Brunswick page.
Want it handled? Get your price in 60 minutes, or call 1-866-904-LAWN.
New Brunswick Lawn Season Questions
When should I cut my grass for the first time in New Brunswick?
Most years, early to mid May. The snow is usually gone by the end of April, but the soil needs to warm up first. Fredericton often greens up a little before Moncton and Saint John.
Should I stop mowing after the first frost?
No. The first frost usually comes in late September or early October, but grass keeps growing until highs stay below 10 C. Normal October highs in New Brunswick are still 12 to 13 C. Keep mowing until growth stops.
How late in the fall do people mow in New Brunswick?
Late October to early November for most lawns. By November, the normal high is about 6 C, and the grass stops growing. A warm fall can push it a little later.
Is there a long grass by-law in Moncton?
Yes. By-law Z-1418 says grass and weeds can't be taller than 20 cm (about 8 inches). That includes the strip of street next to your land. Fredericton and Saint John don't set a grass height in their by-laws.
Rules change, so check with your City before you plan. Sources: ECCC normals, Fredericton A, ECCC normals, Moncton A, ECCC normals, Saint John A, Guelph Turfgrass Institute, Iowa State University Extension, Health Canada, City of Fredericton, No Mow May, City of Fredericton, yard waste, Moncton By-law Z-1418, Eco360 residential program, City of Saint John, leaf and yard waste, City of Saint John, unsightly property, Government of New Brunswick, prohibited pesticides.
