Tennessee planting calendar

When to plant onions in Tennessee — sow, transplant & harvest dates

Tennessee is mostly USDA zone 7a (range 6a-8a). Dates below are derived from onions's frost tolerance and Tennessee's frost window — not generic national averages.

Onions planting timetable for Tennessee

Stage	When in Tennessee	Anchor
Start seeds indoors	early February (February 4)	10 weeks before the last frost (mid-April)
Transplant outside	mid-March (March 18)	28 days before the last frost (mid-April)
First harvest (estimate)	early July (July 6)	~110 days from transplant

Dates are state-wide averages for the dominant zone. Local microclimates — elevation, urban heat, coastal moderation — can shift the window by 1-2 weeks. Use the frost-date calculator for a date tuned to your town.

Why Tennessee's climate shifts the onions dates

Tennessee's last spring frost averages mid-April and first fall frost late October, which sets the whole planting clock. Tennessee has a long, humid, warm season with mild winters. The eastern mountains run a zone cooler than the western lowlands. Sow early — onions bolt once daytime temperatures hold above 24 °C, so the earlier they go in, the longer the harvest.

Onions are day-length sensitive: long-day varieties (zones 1–6) begin bulbing when days exceed 14 hours, short-day types (zones 7–10) bulb at 10–12 hours, and intermediate-day varieties span zones 5–6. Start seeds indoors 10–12 weeks before the last spring frost and transplant out 4–6 weeks before it — young onion seedlings tolerate frost down to about -6 °C once hardened off. In zones 8–10 a second planting from sets in autumn is common, overwintering for an early-summer harvest.

Frost-risk note

Don't plant before mid-April — a hard freeze can still set young plants back. In the eastern Appalachian highlands (zone 6a) the safe date runs a week or two later.

Regional variation within Tennessee

the eastern Appalachian highlands (zone 6a) runs roughly 1-2 weeks behind the state average; the western Mississippi lowlands near Memphis (zone 8a) can plant 1-2 weeks earlier.

Nashville — USDA zone 7b
Memphis — USDA zone 8a
Knoxville — USDA zone 7b
Chattanooga — USDA zone 7b

What else to plant in Tennessee around then

The same early window suits peas, lettuce, spinach, and onion sets.

Quick-grow guide

Sun: Full sun — 6+ hours direct.
Soil temperature for germination: 10-35 °C (50-95 °F).
Spacing: 4-6 inches (10-15 cm) between plants.
Days to harvest: ~110 days from planting out.

Frequently asked questions

When is the best time to plant onions in Tennessee?

In Tennessee (mostly USDA zone 7a), sow onions indoors around early February, transplant outdoors mid-March (before the last frost, mid-April), and harvest from early July. Onions are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

What USDA zone is Tennessee?

Most of Tennessee sits in USDA hardiness zone 7a, with the state spanning roughly 6a-8a from the eastern Appalachian highlands (zone 6a) to the western Mississippi lowlands near Memphis (zone 8a). The last spring frost averages mid-April and the first fall frost late October.

Can you grow onions in Tennessee?

Yes. Tennessee's dominant zone 7a supports onions — the key is timing. Onions are cold-hardy — they tolerate frost and actively prefer cool weather, so they go in well before the last spring frost and bolt in summer heat.

Does the planting date change across Tennessee?

the eastern Appalachian highlands (zone 6a) runs roughly 1-2 weeks behind the state average; the western Mississippi lowlands near Memphis (zone 8a) can plant 1-2 weeks earlier.

What else can I plant in Tennessee around the same time?

The same early window suits peas, lettuce, spinach, and onion sets.

Source and methodology

State zone spans from the USDA Plant Hardiness Zone Map (2023); frost-date averages from NOAA Climate Data Online. Hot-state two-season timing cross-checked against the UF/IFAS Florida Gardening Calendar and the University of Arizona Cooperative Extension planting calendar. Curated by the Growli editorial team.