Oregon · zones 6a–9a
When to plant spinach in Oregon.
Sow between Feb 22 to Apr 5 in a typical year, keyed to Oregon's median last frost around Apr 15. A second, fall sowing fits Aug 11 to Sep 29. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Spinach dates for a typical Oregon season.
Direct sow
Feb 22 to Apr 5
Keyed to the ~Apr 15 last frost. Sow 0.5" deep, 3" apart.
Fall round
Aug 11 to Sep 29
Counted back from the ~Oct 25 first frost.
Harvest
~42 days later
~0.25 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
Spinach matures faster than anything else in this bed, 42 days start to finish, and the state's season has room for as many as twenty-two rounds of it if a gardener actually keeps up the pace.
Twenty-two rounds, sown a little deeper than its neighbors
Spinach seed is bigger and carries more stored energy than most greens sown here, which is why it goes a half inch deep instead of the quarter inch other direct-sown greens in this same garden get. Rows get thinned to 3 inches apart, tight enough that the thinnings themselves, pulled young, usually make the first salad of a round rather than going to waste.
At 42 days to maturity, this is the fastest crop in the group, and the state's 193-day frost-free stretch has room for as many as twenty-two separate rounds of it, spaced out that averages to a new sowing roughly every nine days. Kept up all season, that's closer to a standing habit than a planned event, a pinch of seed added every time the last round is a few days from bolting rather than a calendar reminder.
Why the mild half of the state makes this pace realistic at all
Spinach bolts even faster than lettuce does as the days lengthen, shifting from flat leaf growth to a tall seed stalk in a matter of days, and heat hurries that along rather than starting it. Twenty-two rounds is realistic here because the milder ground near the coast and through the valley rarely adds a long hot stretch on top of the long days, but midsummer sowings still run into the daylight itself. Sown again in early fall, the same crop also tolerates real cold far better than it tolerates heat, standing through a mild coastal or valley winter as a small plant and picking back up in late winter well before a fresh spring sowing could catch up to it.
East of the mountains, the same 42 days asks a lot of a much narrower window, since summer heat arrives fast and hard enough to end a planting early, and winter cold is severe enough that standing a plant through it isn't the reliable option it is on the milder side. A gardener there still gets real value from this crop, but in a handful of deliberate rounds bracketing the heat rather than anything close to twenty-two.
A leaf miner no spray can reach, and two pests at opposite ends of a leaf
Leaf miners are the pest that actually changes how this crop gets managed here, since the larvae feed inside the leaf tissue itself, tunneling pale, winding trails between the top and bottom surfaces where no spray can reach them. Once a leaf shows those trails, the fix isn't a product, it's removing and destroying that leaf before the larva inside it matures, and covering a fresh sowing with lightweight fabric from the day it's sown keeps the adult fly from laying eggs on the leaves in the first place.
Cercospora leaf spot shows up as small, round, tan spots with a darker ring around each one, usually on the older leaves first, sitting on the surface rather than tunneling through it the way a leaf miner does. Flea beetles chew a scatter of small round holes into young leaves, most often on a late sowing still small and tender during the driest part of the year. Aphids cluster on new growth same as they do on most greens in this bed. Each plant only carries about a quarter pound before it bolts and quits, less than any other crop in this bed, but with as many as twenty-two rounds possible in a season, that small number is really the point: this crop was never meant to be grown for size, it's grown for how often it comes back.
In Oregon: watch for
The pests that find spinach here.
A middle-length season, about 193 frost-free days, means spinach overlaps leaf miners for a stretch each summer. Check plants every week or two and treat early.
Winding pale tunnels or blotches inside the leaves.
Organic fix: Pick and destroy mined leaves; cover the row.
Cercospora leaf spot
Round spots with gray centers and a red-purple rim, oldest leaves worst.
Organic fix: Space wider so leaves dry fast, clear old debris, and pull pigweed and lambsquarters nearby.
Your season math: Oregon gives spinach about 193 frost-free days, and it needs roughly 42 days to a first harvest. That fits about 22 re-sown rounds across the season, so you can keep it coming instead of picking once.
Planting spinach in Oregon: questions
When should I plant spinach in Oregon?+
In a typical Oregon year, sow spinach between Feb 22 to Apr 5, keyed to the state's median last frost around Apr 15. There's also a fall window: Aug 11 to Sep 29. 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 spinach 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.