Oregon · zones 6a–9a
When to plant broccoli in Oregon.
Sow or transplant between Feb 22 to Mar 22 in a typical year, keyed to Oregon's median last frost around Apr 15. A second, fall sowing fits Jul 11 to Aug 20. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Broccoli dates for a typical Oregon season.
1 · Start indoors
Jan 11 to Feb 8
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Feb 22 to Mar 22
Keyed to the ~Apr 15 last frost. Sow 0.5" deep, 18" apart.
Fall round
Jul 11 to Aug 20
Counted back from the ~Oct 25 first frost.
Harvest
~60 days later
~1.2 lb per plant over ~3 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
Broccoli takes 60 days here, and west of the Cascades that's enough time to run it twice, in spring and fall, plus a third planting style entirely that doesn't fit either window.
Two windows the standard way, plus a third that isn't really either one
Broccoli starts as a transplant here, going in about twice as deep, a half inch rather than a quarter, and spaced 18 inches apart once transplants carry several true leaves. Both a spring planting and a fall one work here, and 60 days is enough for either to reach a full head.
West of the Cascades, though, many gardeners run a third approach that fits neither window: a summer transplant of a purple sprouting type. Rather than heading up that same year, it grows as a small plant through fall and winter, then produces its real harvest, loose sprouting heads instead of one central crown, the following spring. That's a longer relationship than the standard 60-day crop, and it only works where winters are mild enough for a young plant to stand outside through the cold months, the trade this state's mild side offers and its cold side doesn't.
What threatens spring, and what threatens fall
Spring broccoli's real fight here isn't heat, it's wet ground. A cool, damp spring can keep soil too saturated to work for weeks, pushing transplanting later than planned, and a transplant set into soil still cold and wet is at far greater risk from cabbage root maggot, the same soil-dwelling pest that threatens any brassica put out that early. Waiting for the bed to dry and warm a few extra days, rather than transplanting into ground still cold to the touch, cuts that risk more than any treatment applied later.
Fall broccoli has the easier run west of the Cascades, where a summer planting sizes up under marine-cooled Willamette Valley air instead of real heat, and where that same ocean influence turns autumn into a gradual slide instead of a sudden drop, giving a fall head more time to finish. That gradual cooling is what makes overwintering broccoli, a small plant carried through winter to sprout the next spring, a realistic bet on the valley side of the state. East of the mountains, summer heat runs almost straight into an early, hard frost, and a transplant left out through that kind of winter is far more likely to die than to grow again.
The worm that ruins a head, the fly that starts underground, and 1.2 pounds to show for it
Cabbage worms and loopers matter more here than on a plant grown for loose leaves, since a caterpillar working into a tightening head is far harder to find than one on an open leaf, and worms found only after a head is cut open can ruin it. Checking the head and surrounding leaves every few days once buds start clustering catches most of them before they tunnel in deep. Flea beetles are more of a problem on the fall planting than the spring one, since the driest, warmest stretch of the year usually falls right when fall transplants go into the ground; a scatter of small round holes across a transplant's first new leaves is the sign. Once it pushes a second flush of true leaves in the Willamette Valley's cooling late-summer air, the damage stops mattering.
Aphids gather where developing florets crowd together, harder to spray out once a head has started forming, which makes early scouting worth more here than for any other pest. Black rot spreads fastest on wet foliage, so keeping the 18-inch spacing open rather than letting plants sprawl together, and watering at the soil line instead of overhead, does more to prevent it than any treatment does once established. A plant that gets through all of it produces around 1.2 pounds between its main head and the smaller side shoots that follow, and on the mild side of the state, a purple sprouting planting can add a second, later harvest from the same bed.
In Oregon: watch for
The pests that find broccoli here.
A middle-length season, about 193 frost-free days, means broccoli overlaps cabbage worms & loopers for a stretch each summer. Check plants every week or two and treat early.
Green caterpillars chewing ragged holes; green droppings.
Organic fix: Handpick, cover with netting, spray Bt.
Gray-green clusters tucked into the leaf folds.
Organic fix: Blast with water, then insecticidal soap.
Tiny holes peppering the young leaves.
Organic fix: Row cover from day one; diatomaceous earth.
Black rot
Yellow V-shaped wedges cutting in from the leaf edge, veins blackening inside.
Organic fix: Pull infected plants, water at the base, keep brassicas out of that bed 3 years.
Seedlings wilt, yellow and stall for no reason; white maggots tunnel the roots.
Organic fix: Row cover before the flies are up, when yellow rocket blooms; rotate the bed.
Your season math: Oregon gives broccoli about 193 frost-free days, and it needs roughly 60 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting broccoli in Oregon: questions
When should I plant broccoli in Oregon?+
In a typical Oregon year, sow broccoli or set out transplants between Feb 22 to Mar 22, keyed to the state's median last frost around Apr 15. There's also a fall window: Jul 11 to Aug 20. Your exact dates shift with your ZIP code and microclimate.
When do I start broccoli seeds indoors in Oregon?+
Start seeds inside about 6 weeks before set-out: roughly Jan 11 to Feb 8 for a typical Oregon season.
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 broccoli 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.