Planting Zones of Maine (2024)

Maine spans USDA plant hardiness zones 3b to 7a. Specifically, with their oceanic influence, Maine’s coastal areas fall into warmer zones ranging from Zone 6 to 7a, while inland areas experience colder temperatures, landing between Zones 3 and 5.

So why exactly do these zones matter? Well, every plant has specific temperature tolerances. This means that not every plant likes growing everywhere. Each zone consists of a range of minimum temperatures that plants will most likely survive in during the winter season.

Maine planting zone map

To help you visualize the planting zones in Maine, here’s a map of the state with the planting zones clearly marked:

Planting zones of Maine by region

Maine is divided into several planting zones, ranging from zone 3b in the northernmost parts of the state to zone 7a in the southernmost coastal areas. Here’s a brief overview of the planting zones in Maine’s main regions:

• Southern Maine: This region is primarily in zone 5a through 6a, with some areas along the coast falling in zone 6b and even 7a in the outer reaches of the Penobscot Bay area.
• Northern Maine: The majority of northern Maine is in zones 3b and 4a, with some areas in the northern tip and southern part of the region reaching zones 4b and 5a.
• Central Maine: Most of central Maine is in zones 4b and 5a, with some small areas in zones 4a, 5b, and 6a scattered throughout.

For more detailed information about specific planting zones in each region, you can check out our articles:

• Planting Zones of Southern Maine
• Planting Zones of Northern Maine
• Planting Zones of Central Maine

Maine’s planting zones explained

The USDA has classified regions across the country into plant hardiness zones based on the average annual extreme minimum winter temperatures over a 30-year period. Each zone represents a 10-degree Fahrenheit range of these extreme minimum temperatures. The “a” and ”b” divisions, or half-zones, within these zones indicate subtle variations of 5 degrees Fahrenheit. Here are the temperature ranges for each zone in Maine:

• Zone 3b: -35 to -30°F
• Zone 4a: -30 to -25°F
• Zone 4b: -25 to -20°F
• Zone 5a: -20 to -15°F
• Zone 5b: -15 to -10°F
• Zone 6a: -10 to -5°F
• Zone 6b: -5 to 0°F
• Zone 7a: 0 to 5°F

Hardiness zones show which plants will survive winter in a specific region. For example, a plant listed as “hardy to zone 5b” can tolerate temperatures between -15 and -10 degrees Fahrenheit.

FAQ

How reliable are the plant hardiness zones for determining plant survival in Maine?

While the USDA hardiness zones are a good baseline for winter survival, they don’t consider other important aspects such as soil type, summer heat levels, snow, or rainfall. They should be used as guidance rather than definite advice on plant survival.

Is Maine colder than Alaska?

Surprisingly, certain parts of northern Maine might experience colder temperatures than some areas in Alaska during winter. However, the coldest recorded temperature in northern Maine was -50 degrees F in 2009, while Alaska’s record is much lower at -80 degrees F.

What are the best fruits and vegetables for Maine’s climate zones?

Here are some of the best fruits and vegetables to grow in Maine’s climate zones:

Fruits and vegetables that grow well across all Maine zones:

• Fruits: Apples (cold-hardy varieties like Honeycrisp, Zestar, and Liberty), strawberries, raspberries
• Vegetables: Beets, carrots, lettuce and salad greens, spinach, peas, radishes, potatoes

Zone-specific recommendations:

Zones 3-4 (northern Maine):

• Cold-hardy apple varieties like Idared, Dolgo, Beacon, Haralson
• Cold-hardy root crops like turnips, rutabaga, parsnips
• Quick-maturing greens like arugula, mustard greens

Zones 5-7 (central and southern Maine):

• Fruits: Blueberries, pears (Harrow Delight, Maxine, Golden Spice, and Seckel varieties), peaches (Red Haven or Reliance varieties)
• Vegetables: Tomatoes, peppers, eggplant

Call a lawn care pro for help

Feeling a bit overwhelmed with all the specific details about planting zones? Not quite sure how these guidelines translate to your backyard gardening situation? That’s okay. With this diverse climate, growing conditions in Maine can certainly seem complicated.If you’re unsure where to start, we can help you connect with a local lawn care pro who can help sort out these details.

Main Image Credit: Ken Gallager | Wikimedia Commons | CC BY-SA 3.0