Metro areas

Gardening in Durham-Chapel Hill, NC

This metro spans USDA zones 7b to 8a, so there is no single zone for Durham-Chapel Hill, NC and anyone who gives you one is rounding. 79% of its ZIP codes are zone 8a; the rest are not.

USDA zones 7b–8a 2 zones across 33 ZIP codes
ZIP codes 33 33 have a NOAA station within range
Weather stations 12 NOAA 1991–2020 normals, across 1,759 sq mi

Which zone you are in depends where you are

Durham-Chapel Hill, NC 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 79% in zone 8a and wrong for the other 21%. Here is the actual split.

Zone ZIP codes Share  
8a 26 79%
7b 7 21%

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 March 29 – April 15
First fall freeze October 26 – November 7

Those are the earliest and latest medians among the 12 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 12 stations serving Durham-Chapel Hill, NC it runs 194–222 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 85–89 °F , below the 90 °F point where cool-season crops reliably bolt.

When to start seeds in Durham-Chapel Hill, NC

Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 12 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 February 1 – February 18 8 weeks before
Peppers Start indoors February 1 – February 18 8 weeks before
Broccoli Start indoors February 15 – March 4 6 weeks before
Cabbage Start indoors February 15 – March 4 6 weeks before
Collards Start indoors February 15 – March 4 6 weeks before
Kale Start indoors February 15 – March 4 6 weeks before
Leaf Lettuce Start indoors February 15 – March 4 6 weeks before
Peas Direct sow February 15 – March 4 6 weeks before
Spinach Direct sow February 15 – March 4 6 weeks before
Sweet Potato Start indoors February 15 – March 4 6 weeks before
Tomatoes Start indoors February 15 – March 4 6 weeks before
Bok Choy Start indoors February 22 – March 11 5 weeks before
Kohlrabi Start indoors February 22 – March 11 5 weeks before
Swiss Chard Start indoors February 22 – March 11 5 weeks before
Arugula Direct sow March 1 – March 18 4 weeks before
Baby Salad Greens Direct sow March 1 – March 18 4 weeks before
Beets Direct sow March 1 – March 18 4 weeks before
Green Onions Direct sow March 1 – March 18 4 weeks before
Mustard Greens Direct sow March 1 – March 18 4 weeks before
Okra Start indoors March 1 – March 18 4 weeks before
Radishes Direct sow March 1 – March 18 4 weeks before
Turnips Direct sow March 1 – March 18 4 weeks before
Cabbage Set out March 8 – March 25 3 weeks before
Carrots Direct sow March 8 – March 25 3 weeks before
Collards Direct sow March 8 – March 25 3 weeks before
Collards Set out March 8 – March 25 3 weeks before
Cucumbers Start indoors March 8 – March 25 3 weeks before
Green Onions Set out March 8 – March 25 3 weeks before
Kale Direct sow March 8 – March 25 3 weeks before
Kale Set out March 8 – March 25 3 weeks before
Kohlrabi Direct sow March 8 – March 25 3 weeks before
Kohlrabi Set out March 8 – March 25 3 weeks before
Leaf Lettuce Direct sow March 8 – March 25 3 weeks before
Pumpkins Start indoors March 8 – March 25 3 weeks before
Summer Squash Start indoors March 8 – March 25 3 weeks before
Winter Squash Start indoors March 8 – March 25 3 weeks before
Zucchini Start indoors March 8 – March 25 3 weeks before
Bok Choy Direct sow March 15 – April 1 2 weeks before
Bok Choy Set out March 15 – April 1 2 weeks before
Broccoli Set out March 15 – April 1 2 weeks before
Cilantro Direct sow March 15 – April 1 2 weeks before
Leaf Lettuce Set out March 15 – April 1 2 weeks before
Swiss Chard Direct sow March 15 – April 1 2 weeks before
Swiss Chard Set out March 15 – April 1 2 weeks before
Dill Direct sow March 22 – April 8 1 week before
Bush Beans Direct sow April 5 – April 22 1 week after
Cucumbers Set out April 5 – April 22 1 week after
Pumpkins Direct sow April 5 – April 22 1 week after
Pumpkins Set out April 5 – April 22 1 week after
Summer Squash Direct sow April 5 – April 22 1 week after
Summer Squash Set out April 5 – April 22 1 week after
Sweet Corn Direct sow April 5 – April 22 1 week after
Tomatoes Set out April 5 – April 22 1 week after
Winter Squash Direct sow April 5 – April 22 1 week after
Winter Squash Set out April 5 – April 22 1 week after
Zucchini Direct sow April 5 – April 22 1 week after
Zucchini Set out April 5 – April 22 1 week after
Cucumbers Direct sow April 12 – April 29 2 weeks after
Okra Direct sow April 12 – April 29 2 weeks after
Okra Set out April 12 – April 29 2 weeks after
Peppers Set out April 12 – April 29 2 weeks after
Southern Peas Direct sow April 12 – April 29 2 weeks after
Sweet Potato Set out April 12 – April 29 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 Durham-Chapel Hill, NC

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 57 come through the winter in zone 8a and only 56 in zone 7b. That is a different garden at each end of the same metro.

Zone ZIPs Survive Fail for being too warm
7b 7 56 of 74 3
8a 26 57 of 74 8

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 12 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
Cane Creek Rsvr, NC USC00311429 April 6 November 1 210 days
Chapel Hill 2 W, NC USC00311677 March 31 November 3 218 days
Chapel Hill Williams AP, NC USW00093785 March 29 November 5 222 days
Chatham Wtp, NC USC00311700 April 1 November 7 221 days
Durham 11 W, NC USW00003758 March 31 November 4 217 days
Durham, NC USC00312515 April 2 November 4 217 days
New Hill, NC USC00316122 April 6 November 3 209 days
Raleigh Durham INTL AP, NC USW00013722 March 31 November 4 219 days
Roxboro 7 Ese, NC USC00317516 April 15 October 26 194 days
Sanford 8 NE, NC USC00317656 April 10 October 30 203 days
Siler City 2 N, NC USC00317924 March 31 November 4 220 days
Yanceyville 4 SE, NC USC00319704 March 31 November 4 218 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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