California · zones 7a–10b
When to plant broccoli in California.
Sow or transplant between Nov 23 to Dec 21 in a typical year, keyed to California's median last frost around Jan 14. A second, fall sowing fits Aug 30 to Oct 9. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Broccoli dates for a typical California season.
1 · Start indoors
Oct 12 to Nov 9
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Nov 23 to Dec 21
Keyed to the ~Jan 14 last frost. Sow 0.5" deep, 18" apart.
Fall round
Aug 30 to Oct 9
Counted back from the ~Dec 14 first frost.
Harvest
~60 days later
~1.2 lb per plant over ~3 weeks.
California spans more than one climate: Zone 10 is the most common zone, but the state runs 7a to 10b. 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.
California growing notes
Broccoli asks which California you garden in.
Fog belt or valley heat: pick your broccoli calendar
California's broccoli industry runs through the fog belt around Monterey Bay, where summer highs often stay in the 60s and 70s, cool enough that growers there harvest broccoli in nearly every month of the year. Inland, in the Central Valley and Southern California's warmer valleys, that same steady cool is the one thing broccoli cannot get in summer, and a head that is finishing when afternoons push past 95 degrees for several days running tends to rice: the buds swell loose and grainy and start opening toward yellow instead of holding a tight dome.
Match the variety to your microclimate. Green Magic holds up in warmer inland gardens because it tolerates a wider heat swing before buttoning, while Waltham 29, an old cold-hardy standard, rewards coastal and higher-elevation gardens by shrugging off nights near freezing and pushing side shoots for weeks after the main head is cut. If your garden sits within a few miles of the coastal fog, plan on broccoli surviving mild spells through winter; 20 miles inland, treat it strictly as a spring and fall crop.
Two windows, two different plant-out rules
Because the state carries both a spring and a fall window, timing the transplant age matters more than the calendar itself. Set transplants out at 4 to 6 weeks old, with 4 or 5 true leaves; younger plants stall in cool coastal soil, and older, root-bound plants button early no matter how mild the weather turns.
Feed generously and evenly. Broccoli that runs short on nitrogen midway through head formation produces small, loose heads that never tighten back up even with a late feeding. Side-dress every 3 weeks with a balanced fertilizer, and keep soil moisture steady: a garden that dries to the point of wilting between waterings, then gets soaked, is the other common cause of small, mismatched heads across the same bed.
Coastal humidity brings its own bug list
Cabbage worms and loopers are the everyday threat statewide, both green caterpillars that chew ragged holes and hide in the head's crevices, which is where they end up on the cutting board if you skip the soak. A 10-minute soak in salted water after harvest floats them out; Bt sprayed weekly from transplant onward keeps the population down before it reaches that point.
Coastal fog gardens carry an extra risk inland growers rarely see: aphids that build up fast in the humid, mild air and hide deep in the curd where a hose cannot reach them. Check the underside of leaves and the head itself weekly, starting when heads are golf-ball size, and knock down early colonies with a strong water spray before they move into the crevices where nothing will dislodge them later. Ladybugs and lacewings, both common in coastal California gardens already, will camp on an aphid-infested plant on their own if you skip a broad insecticide early on and let them find the colony first.
In California: watch for
The pests that find broccoli here.
With about 334 frost-free days, broccoli spends longer in the ground here than in most of the country, which widens the window in which cabbage worms & loopers can find it. Scout weekly from midseason and act on the first signs.
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: California gives broccoli about 334 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 California: questions
When should I plant broccoli in California?+
In a typical California year, sow broccoli or set out transplants between Nov 23 to Dec 21, keyed to the state's median last frost around Jan 14. There's also a fall window: Aug 30 to Oct 9. Your exact dates shift with your ZIP code and microclimate.
When do I start broccoli seeds indoors in California?+
Start seeds inside about 6 weeks before set-out: roughly Oct 12 to Nov 9 for a typical California season.
What USDA zone is California?+
California spans zones 7a–10b, mostly zone 10. 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.