Metro areas

Gardening in Bangor, ME

This metro spans USDA zones 4b to 5a, so there is no single zone for Bangor, ME and anyone who gives you one is rounding. 93% of its ZIP codes are zone 5a; the rest are not.

USDA zones 4b–5a 2 zones across 41 ZIP codes
ZIP codes 41 41 have a NOAA station within range
Weather stations 10 NOAA 1991–2020 normals, across 3,397 sq mi

Which zone you are in depends where you are

Bangor, ME covers 2 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 93% in zone 5a and wrong for the other 7%. Here is the actual split.

Zone ZIP codes Share  
5a 38 93%
4b 3 7%

Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.

Your freeze dates

Last spring freeze May 1 – May 17
First fall freeze September 28 – October 8

Those are the earliest and latest medians among the 10 stations serving this metro — not an average, and not one station standing in for the rest. Half of years freeze later than a station's own median.

The spread is the point. Even in a metro that is one hardiness zone throughout, its stations disagree about the last spring freeze. Hardiness zone and frost date measure different things — a zone is the average annual coldest night, a freeze date is when the season turns — and a place can be uniform in one and varied in the other. Use the tools below with your own ZIP rather than the ends of this range.

Your growing season

NOAA publishes a growing-season length for each station, and across the 10 stations serving Bangor, ME it runs 133–157 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 74–79 °F , below the 90 °F point where cool-season crops reliably bolt.

When to start seeds in Bangor, ME

Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 10 stations — the earliest and latest that job falls anywhere in the metro — because no one station speaks for the whole area.

Crop Job When Offset
Green Onions Start indoors March 6 – March 22 8 weeks before
Peppers Start indoors March 6 – March 22 8 weeks before
Broccoli Start indoors March 20 – April 5 6 weeks before
Cabbage Start indoors March 20 – April 5 6 weeks before
Collards Start indoors March 20 – April 5 6 weeks before
Kale Start indoors March 20 – April 5 6 weeks before
Leaf Lettuce Start indoors March 20 – April 5 6 weeks before
Peas Direct sow March 20 – April 5 6 weeks before
Spinach Direct sow March 20 – April 5 6 weeks before
Sweet Potato Start indoors March 20 – April 5 6 weeks before
Tomatoes Start indoors March 20 – April 5 6 weeks before
Bok Choy Start indoors March 27 – April 12 5 weeks before
Kohlrabi Start indoors March 27 – April 12 5 weeks before
Swiss Chard Start indoors March 27 – April 12 5 weeks before
Arugula Direct sow April 3 – April 19 4 weeks before
Baby Salad Greens Direct sow April 3 – April 19 4 weeks before
Beets Direct sow April 3 – April 19 4 weeks before
Green Onions Direct sow April 3 – April 19 4 weeks before
Mustard Greens Direct sow April 3 – April 19 4 weeks before
Okra Start indoors April 3 – April 19 4 weeks before
Radishes Direct sow April 3 – April 19 4 weeks before
Turnips Direct sow April 3 – April 19 4 weeks before
Cabbage Set out April 10 – April 26 3 weeks before
Carrots Direct sow April 10 – April 26 3 weeks before
Collards Direct sow April 10 – April 26 3 weeks before
Collards Set out April 10 – April 26 3 weeks before
Cucumbers Start indoors April 10 – April 26 3 weeks before
Green Onions Set out April 10 – April 26 3 weeks before
Kale Direct sow April 10 – April 26 3 weeks before
Kale Set out April 10 – April 26 3 weeks before
Kohlrabi Direct sow April 10 – April 26 3 weeks before
Kohlrabi Set out April 10 – April 26 3 weeks before
Leaf Lettuce Direct sow April 10 – April 26 3 weeks before
Pumpkins Start indoors April 10 – April 26 3 weeks before
Summer Squash Start indoors April 10 – April 26 3 weeks before
Winter Squash Start indoors April 10 – April 26 3 weeks before
Zucchini Start indoors April 10 – April 26 3 weeks before
Bok Choy Direct sow April 17 – May 3 2 weeks before
Bok Choy Set out April 17 – May 3 2 weeks before
Broccoli Set out April 17 – May 3 2 weeks before
Cilantro Direct sow April 17 – May 3 2 weeks before
Leaf Lettuce Set out April 17 – May 3 2 weeks before
Swiss Chard Direct sow April 17 – May 3 2 weeks before
Swiss Chard Set out April 17 – May 3 2 weeks before
Dill Direct sow April 24 – May 10 1 week before
Bush Beans Direct sow May 8 – May 24 1 week after
Cucumbers Set out May 8 – May 24 1 week after
Pumpkins Direct sow May 8 – May 24 1 week after
Pumpkins Set out May 8 – May 24 1 week after
Summer Squash Direct sow May 8 – May 24 1 week after
Summer Squash Set out May 8 – May 24 1 week after
Sweet Corn Direct sow May 8 – May 24 1 week after
Tomatoes Set out May 8 – May 24 1 week after
Winter Squash Direct sow May 8 – May 24 1 week after
Winter Squash Set out May 8 – May 24 1 week after
Zucchini Direct sow May 8 – May 24 1 week after
Zucchini Set out May 8 – May 24 1 week after
Cucumbers Direct sow May 15 – May 31 2 weeks after
Okra Direct sow May 15 – May 31 2 weeks after
Okra Set out May 15 – May 31 2 weeks after
Peppers Set out May 15 – May 31 2 weeks after
Southern Peas Direct sow May 15 – May 31 2 weeks after
Sweet Potato Set out May 15 – May 31 2 weeks after

The week offsets are conventional extension guidance and vary by variety; the freeze dates they are counted from are measured. For a single date rather than a range, run when do I start my seeds? with your own ZIP code.

What survives the winter changes across Bangor, ME

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 48 come through the winter in zone 5a and only 34 in zone 4b. That is a different garden at each end of the same metro.

Zone ZIPs Survive Fail for being too warm
4b 3 34 of 74 0
5a 38 48 of 74 0

The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.

The 10 stations behind these numbers

Every figure above comes from these, and each is named so you can check it. Distances vary by ZIP code, so the tools report yours rather than this page guessing.

Station NOAA ID Last spring freeze First fall freeze Season
Bangor INTL AP, ME USW00014606 May 4 October 4 152 days
Corinna, ME USC00171628 May 8 October 3 148 days
Dover-Foxcroft WWTP, ME USC00171975 May 15 September 28 134 days
E Sangerville, ME USC00172440 May 6 October 7 153 days
Lincoln Sanitary District/Wtp, ME USC00174683 May 4 October 6 153 days
Millinocket Wastewater, ME USC00175305 May 17 September 29 133 days
Old Town 2 W, ME USW00094644 May 13 September 28 137 days
Orono, ME USC00176430 May 1 October 6 157 days
Patten 2, ME USC00176594 May 13 September 30 138 days
Topsfield 2, ME USC00178792 May 6 October 8 155 days

These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.

Work out your own dates

Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.

Where these numbers come from

The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.

This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.

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