When to plant lettuce in zone 7a

Transplant outdoors around Apr 2. That is 2 weeks before zone 7a's median last frost, Apr 161. Across most of zone 7a that date falls between Mar 21 and Apr 14.

Why a range: zone 7a is defined by winter lows, not frost dates. Its ZIP codes have median last frosts from Apr 4 to Apr 282, so a single zone date can be weeks off for you. The rule comes from Oregon State University Extension Service.

Last reviewed: 2026-11-02
Stations: 865
ZIP codes: 3,807

Photo: Zoran Milosavljevic / Pexels

These dates use the typical last frost for the whole zone. Your ZIP code gives a closer answer.

Start indoorsOregon State, central ORStart indoors across most of the zone: Feb 15 to Mar 10Start indoors at the zone median: Feb 27 (Oregon State, central OR)
Transplant outdoorsOregon State, central ORTransplant outdoors across most of the zone: Mar 21 to Apr 14Transplant outdoors at the zone median: Apr 2 (Oregon State, central OR)
Sow outdoorsColorado StateSow outdoors across most of the zone: Mar 7 to Apr 14Sow outdoors at the zone median: Mar 19 to Apr 2 (Colorado State)

Start indoors
Plant outdoors
Range across the zone
Frost-free season (median)
Spring frost risk (90% to 10%)
Fall frost risk (10% to 90%)

Figure 1. Lettuce in zone 7a. Dark bars: at the zone's median frost dates. Pale bars: across most of the zone's ZIP codes. Hatched blue: where the zone's last and first frosts fall.

Start seeds indoors: Feb 277 weeks before last frost (Oregon State, central OR)
Transplant outdoors: Apr 2range Mar 21 – Apr 14

What each source says, applied to zone 7a

The same frost dates give different answers depending on whose rule you follow. These are all the published rules we hold for lettuce, worked out at zone 7a's median frost dates.

Table 1. Lettuce rules from every source, at zone 7a's median last frost (Apr 16) and first frost (Oct 25).
Source	What	Rule	Zone 7a median
Colorado State3Used above	Sow outdoors	2-4 weeks before last frost	Mar 19 – Apr 2
Utah State4	Sow outdoors	2 weeks before last frost	Apr 2
Oregon State, central OR1Used above	Transplant outdoors	2 weeks before last frost	Apr 2
Oregon State, central OR1Used above	Start indoors	7 weeks before last frost	Feb 27
Texas A&M (E-502)5	Sow outdoors	From 6 wk before to 2 wk after last frost	Mar 5 – Apr 30
Texas A&M (E-502)5	Plant for fall	10-14 weeks before first frost	Jul 19 – Aug 16

Frost across zone 7a

Last spring frostmedian Apr 16Full range across the zone: Mar 25 to Jun 11Most of the zone (10th to 90th percentile): Apr 4 to Apr 28Zone median: Apr 16
First fall frostmedian Oct 25Full range across the zone: Sep 10 to Nov 17Most of the zone (10th to 90th percentile): Oct 16 to Nov 2Zone median: Oct 25

Frost-free season (median)

Figure 2. Frost dates across zone 7a, from 865 NOAA stations matched to 3,807 ZIP codes.

Planting lettuce with others

Cilantro Extension guidance Cilantro flowers attract aphid-eating beneficial insects (lacewings, lady beetles, parasitic wasps, spiders, syrphid flies) that reduce aphids on lettuce.6
Dill Extension guidance Dill flowers attract aphid-eating beneficial insects (lacewings, lady beetles, parasitic wasps, spiders, syrphid flies) that reduce aphids on lettuce.6
Fennel Extension guidance Fennel flowers attract aphid-eating beneficial insects (lacewings, lady beetles, parasitic wasps, spiders, syrphid flies) that reduce aphids on lettuce.6
Carrots Extension guidance Deep-taprooted carrots paired with shallow, wide-rooted lettuce use different soil layers, so their roots compete less.7 8 8

Sources

Oregon State University Extension Service, When to start seeds indoors in central Oregon, reviewed 2024. Retrieved 2026-11-02.
NOAA National Centers for Environmental Information, U.S. Climate Normals 2020: U.S. Annual/Seasonal Climate Normals (1991-2020), 2021. Retrieved 2026-11-02.
Colorado State University Extension, Vegetable Planting Guide (CMG GardenNotes #720), reviewed September 2024. Retrieved 2026-11-02.
Utah State University Extension, Suggested Vegetable Planting Dates for Utah, January 2018; revised May 2025. Retrieved 2026-11-02.
Texas AgriLife Extension Service, The Texas A&M System, Texas Home Vegetable Gardening Guide (E-502), 2/09. Retrieved 2026-11-02.
Penn State Extension, Herbs Make Good Plant Partners and Companions, Updated April 22, 2026. Retrieved 2026-11-02.
Washington State University Extension, Gardening with Companion Plants (Home Garden Series), EM128E, December 2023. Retrieved 2026-11-02.
University of California Agriculture and Natural Resources (UCCE Master Gardener Program), Companion Planting Chart: Companion planting in the vegetable garden, File dated 2023-09 in URL path; no date printed. Retrieved 2026-11-02.