Maine Planting Zones

Maine, otherwise known as the pine tree state, is the most forested state in the USA. This beautiful region is made up of lakes, rivers, mountains, rocky coastlines, and of course, a vast stretch of forested area.

In this article, you will learn:

This state spans across four different growing zones (3, 4, 5 and 6) with the average minimum temperature ranging between -35° to -5° F (-37.2° to -20.6° C) across different areas of the state.

Image from USDA

Characteristics of Maine Planting Region

The climate in Maine is considered humid continental. Across the state, humid, warm summers and dark, cold winters are the norm. Additional characteristics of this planting region are:

  • Cold storms
  • Heavy snowfall
  • Frequent rain
  • Thunderstorms
  • Heavy fog

The state is also known to have some of the most comfortable summers in the United States. The growing season is relatively long, with frost-free periods, the first frost typically happening around mid-September and the final frost sometime in mid-May.

A forested region in Maine | Photo by Zac Durant on Unsplash 

Challenges of Growing in Maine

1. Short Growing Seasons

Although the planting season may last longer in Maine than in other states with similar zones, it’s still a limited timeframe for growing your garden. If not timed correctly, some crops may struggle to survive if they don’t reach maturity before the first frost. Therefore, planning ahead and knowing frost dates and growing timeframes when planting in this region is vital.

2. Frequent Rain

Consistent rainfall generally happens throughout the peak of the growing season. Some plants may flourish with this weather, but others may struggle. It’s important to monitor your plants and use a covering to protect them during this time.


3. Long Winters

In Maine, the winters are long, dark, and very cold. This extended cool season, coupled with plenty of snow, makes growing even the hardiest vegetables difficult or impossible throughout the winter months. Protective coverings or indoor gardening are recommended to help extend growing seasons in this state.


Winter in Maine | Photo by Kelly Sikkema on Unsplash 

The Benefits of Using a Greenhouse in Maine

There is a multitude of benefits to using a greenhouse in this state! You can extend your planting season by months and even enjoy homegrown warm-season vegetables into the autumn and early winter.

Additionally, with the frequent rain and heavy snow in Maine, a greenhouse will protect your hard work from any damage. Not to mention, greenhouses can also sit comfortably on a levelled base to prevent any flooding during wet months. 

1. Extend your Growing Season

  • Without a Greenhouse:
    The average planting season in Maine lasts around 3-4 months. This is a relatively short timeframe, meaning many vegetables may need to be sprouted indoors and transplanted at a later date.
  • With a Greenhouse:
    Gardeners can expect to extend their growing season to between 7-9 months in this region. By investing in a greenhouse you’ll be able to maximize your harvest time and enjoy fresh homegrown vegetables well into the colder months.

Learn more about specific growing dates for your area and the best vegetables to plant in each part of Maine.


Customer images of the Sungrow and Sigma greenhouses in a similar climate region


2. Grow a Wider Variety of Vegetables 

  • Without a Greenhouse:
    The short planting season in Maine limits options for outdoor gardeners as many vegetables won’t mature before the first frost without some indoor growing assistance. Some of the best cold-hardy plants for standard gardens include:
  • Radish
  • Onions
  • Lettuce
  • Carrot
  • Beets
  • Cauliflower

  • With a Greenhouse:
    Using a greenhouse in this state will allow you to plant a much wider variety of vegetables throughout the year. The following list includes recommended vegetables for greenhouse growing in Maine: 
  • Okra
  • Watermelon
  • Bell Peppers
  • Cantaloupe
  • Sweet Corn
  • Cucumber
  • Eggplant
  • Yellow Squash
  • Zucchini
  • Cherry tomatoes
  • Roma tomatoes
  • Celery
  • Chives
  • Parsnips
  • Leeks
  • Pumpkin
  • Rutabaga
  • Winter Squash
  • Endive


Tomato vine | Photo by Dan Gold on Unsplash

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