Maine planting calendar

When to put transplants or seed in the ground across Maine, worked out from the average last spring and first fall frost for each USDA zone in the state, and what to line up before you commit ground. Written for farms that sell what they grow.

Your zone in Maine: frost dates

Zones 4a–6a run through Maine. Frost dates are long-term averages for planning, not a forecast for your field.

  • Zone 4a
    Aroostook County and the far north
    Last frost
    ~May 22
    First frost
    ~September 15
    Frost-free days
    116
    Winter low
    -30°F to -25°F
  • Zone 5a
    Bangor and the central interior
    Last frost
    ~May 8
    First frost
    ~September 29
    Frost-free days
    144
    Winter low
    -20°F to -15°F
  • Zone 5b
    Portland, Augusta and the southern coast
    Last frost
    ~May 1
    First frost
    ~October 6
    Frost-free days
    158
    Winter low
    -15°F to -10°F
  • Zone 6a
    Kittery and the southern tip
    Last frost
    ~May 1
    First frost
    ~October 1
    Frost-free days
    153
    Winter low
    -10°F to -5°F

What it costs to grow an acre in Maine

No published Maine budget is transcribed here yet, so this page shows planting dates only — we do not publish cost figures we cannot source. Neighboring state budgets from NC State, UGA and UF/IFAS are on the crop profitability page.

Every figure is transcribed from a published land-grant enterprise budget for that state. These are planning budgets built from grower panels and dealer quotes, not surveys of what farms actually spent — your invoices override them everywhere they exist.

When to plant Maine's main crops

Calculated for Zone 5b (Portland and the southern coast). Pick your own zone on the crop page.

  • Tomatoes
    May 8 – May 29
    July 29 – August 26
  • Peppers
    May 15 – June 5
    July 31 – August 28
  • Sweet corn
    May 1 – May 22
    July 22 – August 19
  • Cucumbers
    May 8 – May 29
    July 9 – August 6
  • Summer squash
    May 8 – May 29
    July 4 – August 1
  • Green beans (bush)
    May 1 – May 22
    July 2 – July 30
  • Cabbage
    April 3 – April 24
    June 24 – July 22
  • Broccoli
    April 3 – April 24
    June 14 – July 12
  • Kale
    March 27 – April 17
    May 28 – June 25
  • Carrots
    April 3 – April 24
    June 19 – July 17
  • Lettuce
    March 27 – April 17
    May 18 – June 15
  • Strawberries
    October 9 – October 30
    April 14 – May 12

What zone is my farm?

  • Presque IsleZone 4a
  • BangorZone 5a
  • PortlandZone 5b
  • AugustaZone 5b

If your farm sits in a zone that is not listed here, start from the calendar index and pick the closest match, then confirm with your county extension office.

Before you commit ground

A planting date tells you when a crop can grow — not whether it pays. Work out your breakeven price, then line up who is buying before you plant.

Maine planting and cost questions

What USDA planting zone is Presque Isle, Maine?
The calendar carries Presque Isle in Zone 4a. Average last spring frost is around May 22 and average first fall frost around September 15, which is about 116 frost-free days.
What USDA planting zone is Bangor, Maine?
The calendar carries Bangor in Zone 5a. Average last spring frost is around May 8 and average first fall frost around September 29, which is about 144 frost-free days.
When should I plant tomatoes in Maine?
In Zone 5b (Portland and the southern coast), May 8 – May 29 july 29 – august 26

Other state pages

Dates are calculated from average first and last frost dates for each zone. Your microclimate, elevation and soil temperature can shift any window by a week or more — treat these as starting points and keep your own records.