Oregon · zones 6a–9a
When to plant lettuce in Oregon.
Sow between Mar 8 to Apr 22 in a typical year, keyed to Oregon's median last frost around Apr 15. A second, fall sowing fits Aug 11 to Oct 10. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Lettuce dates for a typical Oregon season.
Direct sow
Mar 8 to Apr 22
Keyed to the ~Apr 15 last frost. Sow 0.25" deep, 6" apart.
Fall round
Aug 11 to Oct 10
Counted back from the ~Oct 25 first frost.
Harvest
~45 days later
~0.4 lb per plant over ~1 weeks.
Oregon spans more than one climate: Zone 8 is the most common zone, but the state runs 6a to 9a. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
Oregon growing notes
At 45 days to maturity, a leaf lettuce here can go back in the ground as many as fifteen times in a season, and how many of those fifteen rounds actually succeed depends heavily on which side of the Cascades the bed sits on.
Fifteen rounds, and what that rhythm actually requires
Seed is how leaf lettuce starts here, sown a quarter inch deep, and once seedlings crowd each other they get thinned to a final 6 inches apart. At that pace, a single sowing is a small commitment, a short row rather than a whole bed, which is the point: this crop is built here to be restarted constantly rather than planted once and left.
Divided evenly across the state's 193-day frost-free stretch, fifteen rounds works out to a fresh short row roughly every twelve or thirteen days, closer to a standing kitchen habit than a seasonal event. A gardener who treats it that way, a pinch of seed added every time the last row starts to bolt or thin out, rarely runs out of salad greens for long.
Where the rhythm holds up, and where it breaks by midsummer
The same mild stretch that lets this fifteen-round rhythm run for months belongs mostly to the valley and the coast, where marine air keeps summer from turning into a real heat wave most years. Lettuce reads heat as a signal to quit making leaves and start making a flower stalk instead, and the leaves turn bitter as that shift happens, so the long window here isn't really about frost dates at all, it's about how rarely the mild side of the state hands the plant a true hot stretch to react to.
East of the mountains, the same crop still gets both a spring and a fall window, but the stretch between them breaks down fast once summer heat takes hold, and a gardener there does better treating it as two short, deliberate plantings bracketing the hot months rather than counting on anything close to fifteen continuous rounds. This state's own zone map backs that up without needing a thermometer: it ranges from a chilly 6a inland to a gentle 9a on the coast, two very different versions of summer packed into one set of numbers.
Slugs, a cutworm collar, and the mildew that follows a wet leaf
Slugs and snails are the pest most closely tied to this climate, thriving in the same damp, mild conditions that make the long lettuce season possible in the first place. Ragged holes chewed overnight and a silvery slime trail left behind by morning are the giveaway. An overturned flower pot or a damp shingle set beside the row works as a simple trap, since both pests crawl under it to hide from daylight and can be scraped into a bucket each morning rather than hunted after dark with a flashlight.
Cutworms work at night too, but low rather than up on the leaves, chewing through a seedling's stem right at the soil line and leaving the top lying on the ground with nothing holding it up. A toothpick or a twig pushed into the soil snug against the stem blocks the worm from wrapping around it, a small trick that works because the worm curls its whole body around the stem to cut through it. Downy mildew shows up as pale yellow patches on top of a leaf with sharp edges where a vein cuts the color off, and a violet-gray fuzz growing on the underside after a run of wet, overcast days confirms it. Aphids close out the list, gathering on the undersides of the youngest leaves. A firm spray from the hose most mornings keeps a light cluster from turning into a heavy one. A single plant here yields around 0.4 pounds of leaves total, unremarkable on its own, but repeated across fifteen rounds in a season it turns into a steady kitchen supply rather than one big harvest that comes and goes.
In Oregon: watch for
The pests that find lettuce here.
A middle-length season, about 193 frost-free days, means lettuce, leaf overlaps aphids for a stretch each summer. Check plants every week or two and treat early.
Clusters tucked into the heart of the head.
Organic fix: Rinse well; insecticidal soap on young plants.
Ragged holes and slime trails, worse after rain.
Organic fix: Iron-phosphate bait; a diatomaceous-earth ring; hand-pick at night.
Seedlings clipped off at the soil line overnight.
Organic fix: Collars around the stems; Bt or diatomaceous earth.
Pale yellow patches boxed in by the leaf veins, with white fuzz underneath.
Organic fix: Give plants room, let them dry between waterings, clear old leaves, and pick resistant varieties.
Your season math: Oregon gives lettuce about 193 frost-free days, and it needs roughly 45 days to a first harvest. That fits about 15 re-sown rounds across the season, so you can keep it coming instead of picking once.
Planting lettuce in Oregon: questions
When should I plant lettuce in Oregon?+
In a typical Oregon year, sow lettuce between Mar 8 to Apr 22, keyed to the state's median last frost around Apr 15. There's also a fall window: Aug 11 to Oct 10. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Oregon?+
Oregon spans zones 6a–9a, mostly zone 8. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many lettuce plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.