What USDA hardiness zone is Knoxville, TN?

Knoxville, TN spans USDA hardiness zones 7a to 7b. 79% of its ZIP codes are zone 7b, so there is no single zone for the metro.

When is the last spring frost in Knoxville, TN?

The median last spring freeze runs March 31 – April 24 across the 19 NOAA weather stations serving Knoxville, TN, from NOAA 1991-2020 Climate Normals. Half of years freeze later than the median.

Place guide

Planting zones in Knoxville, TN

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

USDA zones 7a–7b 2 zones across 73 ZIP codes

ZIP codes 73 73 have a NOAA station within range

Weather stations 19 NOAA 1991–2020 normals, across 3,501 sq mi

Your ZIP code

Get the exact answer for your address

Everything above describes Knoxville, TN as a whole. Hardiness zones and freeze dates are published per ZIP code, so yours is exact — enter it and this page will tell you your zone, which NOAA station it comes from and how far away that station is.

The growing season in Knoxville, TN is closing

Nothing in the 32-crop table still has time to mature here. The first fall freeze normally arrives October 17 – November 4 across the 19 NOAA stations serving this metro area .

Your next season already has a date

The first job of it is 🧅 Green Onions, start indoors, around February 3 – February 27 — counted back from a last spring freeze of March 31 – April 24 here.

Every spring date for your ZIP →

These are ranges across the whole metro area. The ZIP lookup above gives the dates from your own nearest station instead.

All 19 stations agreeAt least one station

Every one of the 19 NOAA stations serving this metro area counts April 24 – October 17 as growing season (176 days). Widening to any single station gives March 31 – November 4 (218 days).

That is a 42-day difference inside one metro area — which is why this page gives ranges rather than a single planting date. The ZIP lookup above resolves it to one station.

Which zone you are in depends where you are

Knoxville, TN 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 7b and wrong for the other 21%. Here is the actual split.

Zone	ZIP codes	Share
7b	58	79%
7a	15	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 31 – April 24

First fall freeze October 17 – November 4

Those are the earliest and latest medians among the 19 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 19 stations serving Knoxville, TN it runs 175–218 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 80–89 °F , below the 90 °F point where cool-season crops reliably bolt. Summer rain over the same months runs 12.2–16.0" across those 19 stations, against the rough inch a week — about 13 inches over the same 92 days — that a vegetable garden is usually reckoned to want. At the middle station that is covered, so watering in Knoxville, TN is for the gaps between storms rather than the whole season. The inches are NOAA's published normals; the inch a week is a rule of thumb, and it takes no account of a 86 °F summer afternoon drying the soil faster than a cool one.

When to start seeds in Knoxville, TN

Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 19 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 3 – February 27	8 weeks before
Peppers	Start indoors	February 3 – February 27	8 weeks before
Broccoli	Start indoors	February 17 – March 13	6 weeks before
Cabbage	Start indoors	February 17 – March 13	6 weeks before
Collards	Start indoors	February 17 – March 13	6 weeks before
Kale	Start indoors	February 17 – March 13	6 weeks before
Leaf Lettuce	Start indoors	February 17 – March 13	6 weeks before
Peas	Direct sow	February 17 – March 13	6 weeks before
Spinach	Direct sow	February 17 – March 13	6 weeks before
Sweet Potato	Start indoors	February 17 – March 13	6 weeks before
Tomatoes	Start indoors	February 17 – March 13	6 weeks before
Bok Choy	Start indoors	February 24 – March 20	5 weeks before
Kohlrabi	Start indoors	February 24 – March 20	5 weeks before
Swiss Chard	Start indoors	February 24 – March 20	5 weeks before
Arugula	Direct sow	March 3 – March 27	4 weeks before
Baby Salad Greens	Direct sow	March 3 – March 27	4 weeks before
Beets	Direct sow	March 3 – March 27	4 weeks before
Green Onions	Direct sow	March 3 – March 27	4 weeks before
Mustard Greens	Direct sow	March 3 – March 27	4 weeks before
Okra	Start indoors	March 3 – March 27	4 weeks before
Radishes	Direct sow	March 3 – March 27	4 weeks before
Turnips	Direct sow	March 3 – March 27	4 weeks before
Cabbage	Set out	March 10 – April 3	3 weeks before
Carrots	Direct sow	March 10 – April 3	3 weeks before
Collards	Direct sow	March 10 – April 3	3 weeks before
Collards	Set out	March 10 – April 3	3 weeks before
Cucumbers	Start indoors	March 10 – April 3	3 weeks before
Green Onions	Set out	March 10 – April 3	3 weeks before
Kale	Direct sow	March 10 – April 3	3 weeks before
Kale	Set out	March 10 – April 3	3 weeks before
Kohlrabi	Direct sow	March 10 – April 3	3 weeks before
Kohlrabi	Set out	March 10 – April 3	3 weeks before
Leaf Lettuce	Direct sow	March 10 – April 3	3 weeks before
Pumpkins	Start indoors	March 10 – April 3	3 weeks before
Summer Squash	Start indoors	March 10 – April 3	3 weeks before
Winter Squash	Start indoors	March 10 – April 3	3 weeks before
Zucchini	Start indoors	March 10 – April 3	3 weeks before
Bok Choy	Direct sow	March 17 – April 10	2 weeks before
Bok Choy	Set out	March 17 – April 10	2 weeks before
Broccoli	Set out	March 17 – April 10	2 weeks before
Cilantro	Direct sow	March 17 – April 10	2 weeks before
Leaf Lettuce	Set out	March 17 – April 10	2 weeks before
Swiss Chard	Direct sow	March 17 – April 10	2 weeks before
Swiss Chard	Set out	March 17 – April 10	2 weeks before
Dill	Direct sow	March 24 – April 17	1 week before
Bush Beans	Direct sow	April 7 – May 1	1 week after
Cucumbers	Set out	April 7 – May 1	1 week after
Pumpkins	Direct sow	April 7 – May 1	1 week after
Pumpkins	Set out	April 7 – May 1	1 week after
Summer Squash	Direct sow	April 7 – May 1	1 week after
Summer Squash	Set out	April 7 – May 1	1 week after
Sweet Corn	Direct sow	April 7 – May 1	1 week after
Tomatoes	Set out	April 7 – May 1	1 week after
Winter Squash	Direct sow	April 7 – May 1	1 week after
Winter Squash	Set out	April 7 – May 1	1 week after
Zucchini	Direct sow	April 7 – May 1	1 week after
Zucchini	Set out	April 7 – May 1	1 week after
Cucumbers	Direct sow	April 14 – May 8	2 weeks after
Okra	Direct sow	April 14 – May 8	2 weeks after
Okra	Set out	April 14 – May 8	2 weeks after
Peppers	Set out	April 14 – May 8	2 weeks after
Southern Peas	Direct sow	April 14 – May 8	2 weeks after
Sweet Potato	Set out	April 14 – May 8	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 Knoxville, TN

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 58 come through the winter in zone 7a 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
7a	15	58 of 74	1
7b	58	56 of 74	3

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.

Cautious — shortens the seasonMedian across stationsOptimistic

Last spring freeze: Plan to May 13 to be careful. Median March 31 – April 24 across 19 stations; March 11 is the optimistic end.
First fall freeze: Plan to October 4 to be careful. Median October 17 – November 4 across 19 stations; November 18 is the optimistic end.

NOAA publishes these as probabilities, not averages — the middle figure is a median, so half of years fall either side of it. The cautious end is the 10% tail: in roughly nine years in ten the freeze falls on the safe side of it.

The 19 stations behind these numbers

All 19 NOAA stations whose normals this page quotes, spanning about 123 km north to south. Every one is named with its identifier in the station list below — this page does not single one out, because no one station speaks for a whole metro area.

A relative sketch, not a map with a projection: longitude is adjusted for latitude so the shape is not stretched, and there is no basemap. For the one station nearest a specific address, with its real distance, use the ZIP lookup above.

Every figure above comes from these, and each is named so you can check it. Which station serves a given ZIP code, and how far away it is, varies across the metro — the table below gives it per ZIP code rather than this page averaging it.

Station	NOAA ID	Last spring freeze	First fall freeze	Season
Allardt, TN	USC00400081	April 17	October 23	188 days
Decatur 7Ne, TN	USC00402388	April 10	October 27	199 days
Jefferson City, TN	USC00404613	April 24	October 17	175 days
Kingston, TN	USC00404871	April 3	November 4	215 days
Knoxville Exp Stn, TN	USC00404946	April 11	October 28	198 days
Knoxville Mcghee Tyson AP, TN	USW00013891	April 1	November 2	215 days
Lancing 6 NW, TN	USC00405040	April 21	October 17	177 days
Lenoir City, TN	USC00405158	April 5	November 1	210 days
Morristown Radio Wcrk, TN	USC00406271	April 10	October 28	201 days
Morristown Wfo, TN	USC00406272	March 31	November 4	217 days
Newcomb, TN	USC00406493	April 18	October 24	187 days
Norris, TN	USC00406619	April 22	October 25	184 days
Oak Ridge Asos, TN	USW00053868	March 31	November 4	218 days
Oak Ridge Atdd, TN	USW00003841	April 5	November 1	210 days
Rockwood 2, TN	USC00407834	April 8	October 31	203 days
Sevierville, TN	USC00408179	April 6	October 29	205 days
Tapoco, NC	USC00318492	April 17	October 27	193 days
Tazewell, TN	USC00408868	April 23	October 19	177 days
Townsend 5S, TN	USC00409065	April 20	October 22	185 days

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

Every ZIP code in Knoxville, TN

Zones are published per ZIP code, not per metro area, so this is the exact answer rather than the metro area's average. The station column is the nearest one to that ZIP code's centroid and how far away it is — the same figure the tools use, shown here so you can see which ZIP codes are well covered and which are reaching.

ZIP code	USDA zone	Nearest NOAA station	Distance
37701	7b	Knoxville Mcghee Tyson AP, TN	2.9 km
37705	7b	Norris, TN	4.8 km
37708	7b	Morristown Radio Wcrk, TN	13.8 km
37709	7b	Jefferson City, TN	17.9 km
37710	7a	Oak Ridge Asos, TN	16.6 km
37714	7a	Norris, TN	17.5 km
37716	7b	Oak Ridge Asos, TN	10.6 km
37719	7b	Oak Ridge Atdd, TN	16.3 km
37721	7b	Norris, TN	23.9 km
37726	7a	Lancing 6 NW, TN	8.5 km
37729	7b	Newcomb, TN	13.2 km
37733	7a	Allardt, TN	16.3 km
37737	7b	Lenoir City, TN	13.1 km
37742	7b	Lenoir City, TN	14.5 km
37748	7b	Kingston, TN	9.9 km
37754	7b	Norris, TN	8.7 km
37757	7b	Norris, TN	6.7 km
37762	7a	Newcomb, TN	5.5 km
37763	7b	Kingston, TN	5.2 km
37766	7a	Newcomb, TN	19.2 km
37769	7b	Norris, TN	8.6 km
37770	7a	Lancing 6 NW, TN	7.8 km
37771	7b	Lenoir City, TN	7.5 km
37772	7b	Lenoir City, TN	4.6 km
37774	7b	Lenoir City, TN	10.9 km
37777	7b	Knoxville Mcghee Tyson AP, TN	6.0 km
37779	7b	Norris, TN	27.1 km
37801	7b	Knoxville Mcghee Tyson AP, TN	18.4 km
37803	7b	Knoxville Mcghee Tyson AP, TN	17.5 km
37804	7b	Knoxville Mcghee Tyson AP, TN	8.8 km
37806	7b	Sevierville, TN	20.8 km
37807	7b	Norris, TN	21.6 km
37819	7a	Newcomb, TN	3.5 km
37828	7b	Norris, TN	1.9 km
37829	7b	Kingston, TN	17.9 km
37830	7b	Oak Ridge Atdd, TN	5.5 km
37840	7b	Oak Ridge Asos, TN	12.9 km
37845	7a	Oak Ridge Asos, TN	21.1 km
37846	7b	Decatur 7Ne, TN	17.1 km
37847	7a	Newcomb, TN	16.1 km
37848	7b	Jefferson City, TN	22.6 km
37849	7b	Oak Ridge Asos, TN	17.3 km
37853	7b	Knoxville Mcghee Tyson AP, TN	7.1 km
37854	7a	Rockwood 2, TN	5.8 km
37861	7b	Morristown Wfo, TN	12.8 km
37866	7b	Norris, TN	24.5 km
37871	7b	Sevierville, TN	15.0 km
37872	7a	Lancing 6 NW, TN	13.9 km
37878	7b	Tapoco, NC	17.0 km
37881	7a	Tazewell, TN	19.2 km
37882	7a	Townsend 5S, TN	3.9 km
37886	7b	Townsend 5S, TN	15.6 km
37887	7a	Lancing 6 NW, TN	13.5 km
37888	7b	Tazewell, TN	15.1 km
37902	7b	Knoxville Exp Stn, TN	7.8 km
37909	7b	Knoxville Exp Stn, TN	8.0 km
37912	7b	Knoxville Exp Stn, TN	12.5 km
37914	7b	Knoxville Exp Stn, TN	17.3 km
37915	7b	Knoxville Exp Stn, TN	9.5 km
37916	7b	Knoxville Exp Stn, TN	6.5 km
37917	7b	Knoxville Exp Stn, TN	12.2 km
37918	7b	Knoxville Exp Stn, TN	18.0 km
37919	7b	Knoxville Exp Stn, TN	4.3 km
37920	7b	Knoxville Exp Stn, TN	9.0 km
37921	7b	Knoxville Exp Stn, TN	9.8 km
37922	7b	Knoxville Mcghee Tyson AP, TN	11.4 km
37923	7b	Knoxville Exp Stn, TN	11.6 km
37924	7b	Knoxville Exp Stn, TN	19.3 km
37929	7b	Knoxville Exp Stn, TN	8.0 km
37931	7b	Oak Ridge Asos, TN	11.3 km
37932	7b	Oak Ridge Atdd, TN	10.5 km
37934	7b	Lenoir City, TN	12.3 km
37938	7b	Norris, TN	14.7 km

ZIP-code positions are area centroids, so a large rural ZIP code's listed distance is measured from the middle of its area rather than from any particular address in it.

Your own ZIP

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.

What survives my winter?
Runs on the hardiness zone, so it answers for all of Knoxville, TN at once — zone across 74 perennial fruits, berries, vegetables and herbs.
When do I start my seeds?
Dates every spring job from your own last freeze — sow indoors, set out, direct sow.
When do I sow the next round?
How often each crop is worth re-sowing, and when the next sowing is due.
What can I still plant?
Counts the growing days left before your first fall freeze, crop by crop.

Other places to compare

These metros span exactly the same zones — 7a–7b — so the same plants are in and out of range across them. The freeze dates and the spring calendar are their own.

Gardening in Tennessee — zones 6b– 8a covers the whole state: how its 633 ZIP codes divide between 4 hardiness zones, and the freeze dates across every NOAA station in it.

Other metro areas in TN:

Chattanooga, TN-GA Zones 7b–8a
Kingsport-Bristol, TN-VA Zones 7a–7b
Jackson, TN Zone 7b
Clarksville, TN-KY Zones 7a–7b
Johnson City, TN Zones 6b–7b
Cleveland, TN Zones 7b–8a
Morristown, TN Zone 7b
Nashville-Davidson--Murfreesboro--Franklin, TN Zones 7a–7b
Memphis, TN-MS-AR Zones 7b–8a

All 388 metro areas, by state

Gear

If you want to act on this

Each link opens an Amazon search rather than a product we picked. We have not tested these and do not rank them — the search is the honest version, and you choose.

Row cover and frost clothThe season here closes at the first fall freeze dated above — a cover buys back some of those days at the end.
MulchFor the perennials nearest their cold limit in zone 7a, where an insulated crown is what decides whether they come back.

As an Amazon Associate we earn from qualifying purchases. That costs you nothing extra, and it buys no influence over anything on this site: the dates come from NOAA normals and the zones from the USDA, and no product affects either.

Sources

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.

All metro areas