Maine Planting Zones – Growing Zones Guide

What Planting Zone Is Maine In?

Maine sits on the northeastern edge of the United States, where cold Labrador Current waters, Atlantic storms, and significant changes in elevation all shape the climate. On the 2023 USDA Plant Hardiness Zone Map, Maine spans roughly zones 3b–7a, with most gardeners living in zones 4a–5b and new pockets of zone 6–7a along the southern and coastal fringe as winters trend warmer. Higher interior plateaus and northern highlands can be about a half-zone colder than nearby lowlands.

• Southern & Coastal Maine (York & Cumberland Counties): Portland, South Portland, Cape Elizabeth, Saco, and Kittery sit mainly in zones 5b–7a, with some of the state’s longest growing seasons and mildest winter lows.
• Midcoast & Downeast Shore: Brunswick, Bath, Rockland, Belfast, Ellsworth, and Bar Harbor are generally zones 5a–6b, moderated by the ocean but still prone to chilly spring sea breezes and fall storms.
• Central Rivers, Lakes & Foothills: Augusta, Waterville, Lewiston–Auburn, and lake-country towns around Sebago and Belgrade typically fall in zones 4b–5b, great for hardy fruits, vegetables, and perennials.
• Western Mountains & Highlands: Rangeley, Farmington, Bethel, and upland towns in Franklin, Oxford, Somerset, and Piscataquis Counties are often zones 4a–4b, with long, snowy winters and shorter, cooler summers.
• Northern Interior & Aroostook County: Caribou, Presque Isle, Fort Kent, and the St. John Valley include some of Maine’s coldest spots, largely zones 3b–4a, with the shortest frost-free windows and very hardy plant palettes.

USDA Hardiness Zone Map for Maine

The updated 2023 USDA Plant Hardiness Zone Map is based on 30-year averages (1991–2020) of each location’s coldest winter temperatures. In Maine, the map shows a broad sweep from frigid northern highlands and interior mountains (zones 3b–4a) to milder central river valleys (4b–5b) and increasingly temperate coastal areas, where parts of York and Cumberland Counties now fall into zones 6a–7a.

Official 2023 USDA Maine planting zone map, based on 1991–2020 climate data.

Use the map together with your ZIP code to pinpoint your exact Maine garden zone. Look up your Maine planting zone by ZIP code using the USDA tool, then come back here or visit our Plant Finder for plants tailored to your zone, soil, and sun conditions.

Maine Growing Zones by Region

Maine may be a single state on the map, but gardeners know it feels like several. Ocean fog, elevation, cold river valleys, and even stone walls and barns can nudge a garden a half to a full zone warmer or colder than nearby sites.

Southern & Coastal Maine (Approx. Zones 5b–7a)

This region includes Portland, South Portland, Falmouth, Scarborough, Saco, Biddeford, Kittery, and neighboring coastal communities in York and Cumberland Counties.

• Maritime influence and urban heat keep winter lows slightly milder, giving some of Maine’s longest frost-free seasons.
• Well-drained, south-facing gardens can host borderline-hardy shrubs, vines, and perennials that would struggle farther inland.
• Soils range from coastal sands to heavier glacial tills; regular compost and mulch help retain moisture and buffer salt-laden winds.

Midcoast & Downeast (Approx. Zones 5a–6b)

From Brunswick and Bath up through Rockland, Belfast, Ellsworth, and Bar Harbor, this region hugs the dramatic, rocky shoreline and island-dotted bays.

• Cold Atlantic waters can delay spring warmth, so soil often stays cool well into May even when air temperatures tease you into planting early.
• Excellent for cool-season crops, hardy herbs, wild blueberries, and mixed ornamental beds that enjoy summer fog and moderate heat.
• Salt spray, wind, and ledgy soils reward tough, deep-rooted plants and generous mulching.

Central Rivers, Lakes & Foothills (Approx. Zones 4b–5b)

Augusta, Waterville, Bangor, Lewiston–Auburn, and surrounding inland towns sit in a transitional band between the milder coast and colder northern highlands.

• Great all-purpose gardening country for hardy fruit trees, mixed vegetables, and classic New England perennials.
• Average last frosts typically arrive in early–mid May, with first frosts returning from late September into early October, depending on elevation and proximity to water.
• Glacial till soils can be rocky or compacted—raised beds, compost, and mulch make a big difference in yields.

Western Mountains & Highlands (Approx. Zones 4a–4b)

From the Mahoosuc Range and ski-country towns like Bethel and Sugarloaf to the hills of Franklin, Oxford, Somerset, and Piscataquis Counties, this region is snow country.

• Cold winters and shorter growing seasons favor hardy perennials, conifers, native shrubs, and fast-maturing vegetables.
• Average last frosts can linger into late May, with first frosts often sneaking in by late September on exposed slopes.
• South-facing slopes, stone walls, and darker mulches help capture extra warmth.

Northern Interior & Aroostook County (Approx. Zones 3b–4a)

From Bangor north through Millinocket, Houlton, Caribou, Presque Isle, Fort Kent, and the St. John Valley, winters are long, cold, and snowy—and summers can be beautifully productive when timed right.

• Very cold winters and relatively short frost-free windows; focus on hardy perennials, shelterbelts, and quick-maturing vegetables and grains.
• The Old Farmer’s Almanac estimates average last frost dates around early May in Portland and Augusta, mid-May in Bangor, and late May in Presque Isle, reflecting the northward cooling trend.
• Choose wind-sheltered sites, darker mulches, and cold-tolerant, short-season varieties to make the most of the growing season.

Best Plants for Maine Planting Zones

Once you know your Maine planting zone—and whether you garden on a foggy peninsula, beside an inland lake, or in the northern potato country—you can work with your climate. Focus on plants rated for your hardiness zone (3–7 across the state, with most gardeners between 3 and 6) and time annual crops around your local frost dates and soil conditions.

Vegetables for Maine Growing Zones

• Cool-season crops (spring and fall statewide): lettuce, spinach, arugula, kale, collards, peas, broccoli, cabbage, carrots, beets, potatoes, parsnips, turnips, and radishes.
• Warm-season crops (plant after your last frost): tomatoes, peppers, zucchini and other summer squash, pumpkins, cucumbers, beans, sweet corn, and short-season melons in the warmest locations.
• Short-season & northern favorites (zones 3b–4b): Quick-maturing salad mixes, baby carrots, radishes, bush beans, compact determinate tomatoes, and cold-frame greens help northern and high-elevation gardeners harvest more in less time.

Fruits & Trees for Maine Hardiness Zones

• Statewide staples (zones 3–6, with some 7a pockets): apples, pears, cherries, and hardy plums thrive when matched to cold-hardy rootstocks and sited away from frost pockets.
• Small fruits: Maine-famous lowbush and highbush blueberries, strawberries, currants, hardy blackberries and raspberries, and elderberries all love Maine’s typically acidic soils.
• Warm-pocket experiments (mild 6b–7a sites): In sheltered, south-facing courtyards along the southern coast, adventurous gardeners may trial hardy figs or keep citrus and other tender fruit trees in containers that overwinter indoors.

Flowers & Ornamentals for Maine Garden Zones

• Reliable perennials: coneflower, black-eyed Susan, yarrow, catmint, lavender (in well-drained, sunny spots), and ornamental sages suit sunny beds in zones 4–7.
• Shade-garden classics: Hostas, ferns, heucheras, astilbes, and woodland phlox brighten understories beneath maples, oaks, and spruces.
• Structural plants: serviceberry, hydrangeas, lilacs, ornamental grasses, and hardy roses add four-season interest and wildlife shelter.

Native Plants for Maine Landscapes

Maine native plants are adapted to local soils, rainfall, and wildlife, making them resilient and ecologically powerful. Mix native wildflowers, shrubs, grasses, and trees for a landscape that feels at home from the rocky coast to the North Woods and supports bees, butterflies, and songbirds.

• Native wildflowers: bee balm (Monarda), New England aster (Symphyotrichum novae-angliae), goldenrod (Solidago spp.), wild columbine (Aquilegia canadensis), and native milkweeds for meadow-style and cottage gardens.
• Native grasses: little bluestem (Schizachyrium scoparium), switchgrass (Panicum virgatum), and tufted hairgrass (Deschampsia cespitosa) for meadows and borders.
• Native shrubs & trees: sugar maple, red maple, paper birch, red oak, white pine, American hazelnut, and winterberry holly for structure, fall color, and wildlife food.

Browse curated lists like great pollinator plants for Maine and monarch nectar plants for Maine to build a garden that hums with life from spring ephemerals through snowy evergreens.

Interactive Maine Planting Calendar (General Guide)

Tap a month to see what to plant in Maine by zone. Use this as a starting point, then adjust for your exact frost dates, elevation, and whether you garden on the southern coast, in central river valleys, or in northern highlands.

Maine Gardening Tips by Zone

Maine gardeners juggle rocky, acidic soils; cold, snowy winters; fog and sea breezes; blackflies; deer and moose; surprise spring frosts; and rapidly changing weather. These tips help your plants thrive from zone 3b to 7a (with a few even colder peaks in exposed highlands):

• Know your microclimate. A sheltered Portland backyard may behave like a warmer zone 7a, while a windswept field near Presque Isle feels like zone 3—even if maps say otherwise.
• Time your seasons. On the southern and coastal fringe you can plant earlier and harvest later. In central and northern zones, rely on compact, quick-maturing varieties and season-extension tools.
• Improve challenging soils. Much of Maine has stony, acidic, or compacted soils. Add compost regularly, test pH, lime when needed, and consider raised beds for vegetables and herbs.
• Water wisely. Use drip irrigation or soaker hoses under mulch to conserve water and limit foliar diseases during humid spells.
• Use mulch generously. Organic mulches moderate soil temperature, suppress weeds, and reduce splash-borne diseases on tomatoes, roses, and cucurbits.
• Rotate crops. Moving plant families around the garden each year helps manage pests and soil-borne diseases, especially in small vegetable plots.
• Plan for wildlife. Fencing, tree guards, and resistant plant choices help you coexist with deer, rabbits, voles, and the occasional moose or bear.
• Lean on natives. Let native trees, shrubs, and perennials form the backbone of your landscape, with tender or thirsty plants tucked into key protected spots.