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When to plant in Brunswick, ME

USDA Zone 5b

Here are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Brunswick, Maine — all computed from Brunswick's nearest NOAA weather station.

In zone 5b, Brunswick gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.

Station · BRUNSWICK NAS · 1.6 km
Last spring frost
May 2
50% chance · 32°F
First fall frost
October 10
50% chance · 32°F
Growing season
161 days
frost-free
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Frost calendar for BrunswickA year-band showing 32°F frost risk from January to December for Brunswick: last spring frost around May 2, first fall frost around October 10, about 161 frost-free days between.
Shaded months carry frost risk; the clear span is the average frost-free season.

Frost probability

BRUNSWICK NAS · 1991–2020

The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Brunswick’s own odds, recorded at BRUNSWICK NAS.

Frost-probability curves for BrunswickProbability of the last spring frost and first fall frost by date at 32°F. The last spring frost is most likely around May 2 and the first fall frost around October 10, giving about 161 frost-free days.
Last spring frostFirst fall frostbold = 32°F · thin = 28°F / 36°F · dot = 50% date · band = 10–90% window
ThresholdSPRING 10%SPRING 50%SPRING 90%FALL 10%FALL 50%FALL 90%
36°FMay 26May 13May 2Sep 20Oct 1Oct 12
32°FMay 14May 2Apr 24Sep 29Oct 10Oct 27
28°FMay 1Apr 22Apr 10Oct 8Oct 23Nov 7

Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.

What to plant now

TODAY · JULY 19
Fall sowopen now
Broccoli
July 18August 1
Fall sowopen now
Cabbage
July 18August 1
Fall sowopen now
Carrot
July 18August 1
Fall sowopen now
Cauliflower
July 18August 1
Fall sowopen now
Napa Cabbage
July 18August 15
Fall sowin 13 days
Beet
August 1August 15
Fall sowin 13 days
Collards
August 1August 29
Fall sowin 13 days
Endive
August 1August 15
Fall sowin 13 days
Escarole
August 1August 15
Fall sowin 13 days
Fennel (Bulb)
August 1August 15
Fall sowin 13 days
Kale
August 1August 29
Fall sowin 13 days
Kohlrabi
August 1August 29
Fall sowin 13 days
Peas
August 1August 15
Fall sowin 13 days
Radicchio
August 1August 15
Fall sowin 13 days
Swiss Chard
August 1August 15
Fall sowin 13 days
Turnip
August 1August 29
Fall sowin 27 days
Arugula
August 15September 12
Fall sowin 27 days
Bok Choy
August 15August 29
Fall sowin 27 days
Chervil
August 15September 12
Fall sowin 27 days
Cilantro
August 15September 12
Fall sowin 27 days
Claytonia (Miner's Lettuce)
August 15September 12
Fall sowin 27 days
Corn Salad (Mâche)
August 15September 12
Fall sowin 27 days
Gai Lan (Chinese Broccoli)
August 15August 29
Fall sowin 27 days
Lettuce
August 15September 12
Fall sowin 27 days
Mizuna
August 15September 12
Fall sowin 27 days
Mustard Greens
August 15September 12
Fall sowin 27 days
Radish
August 15September 12
Fall sowin 27 days
Shungiku (Edible Chrysanthemum)
August 15August 29
Fall sowin 27 days
Spinach
August 15September 12
Fall sowin 27 days
Tatsoi
August 15September 12

Add these crops to your calendar (.ics) ↓

Full-year planting calendar

Start indoorsTransplantDirect sowFall sow

Each bar is the exact window to take a planting action in Brunswick, drawn to the day from the local frost dates. The dashed line is today.

Nearby weather stations

3 within 18 km · complete 32°F normals

When stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.

BRUNSWICK NAS
Primary
2 km · 21 m elevation
SPRING
May 2
FALL
Oct 10
BATH
8 km · 8 m elevation
SPRING
May 10
FALL
Oct 6
DURHAM
18 km · 43 m elevation
SPRING
May 15
FALL
Oct 2

Brunswick planting FAQ

When is the last spring frost in Brunswick, ME?

Plan for the last spring frost in Brunswick around May 2 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.

When is the first fall frost in Brunswick, ME?

In Brunswick, the first 32°F freeze of fall lands around October 10 on average. Time your last harvests and any season-extension cover before it.

What hardiness zone is Brunswick in?

Brunswick is in USDA hardiness zone 5b. In zone 5b, winters are cold — pick cold-hardy varieties and protect tender crops.

How long is the growing season in Brunswick?

Brunswick has about 161 frost-free days — a moderate growing season — between the average last spring frost (May 2) and first fall frost (October 10).

When should I plant tomatoes in Brunswick?

For Brunswick, sow tomatoes indoors about March 7–March 21 and move the seedlings out around May 9, after the last spring frost.

Planting reminders

Never miss a window in Brunswick

An email when it’s time to start seeds, transplant, and sow — timed to Brunswick’s frost dates. Double opt-in, one-click unsubscribe, no spam.

Nearby cities

8 within reach

Frost dates recorded at BRUNSWICK NAS, 2 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.

Cite this page
BlissGarden. "When to Plant in Brunswick, ME — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00014611. Retrieved from https://blissgarden.com/maine/brunswick.
When to Plant in Brunswick, ME — Frost Dates & Zone 5b — BlissGarden