Masterclass: Broccoli — Bay Area (Sunset 14-17; USDA 9-10)

Garden Nerd
Sep 10
2 min read

Broccoli rewards Bay Area growers when timing matches microclimate. We pair USDA 9–10 (hardiness) with Sunset 14–17 for local precision — fog, wind, summer highs, and season length drive real-world results. Sunset is more granular than USDA, which tracks winter lows only; that’s why coast vs. inland timing differs. Use the gardening charts as a local baseline, then shift earlier inland (to dodge spring heat) or steady the pace near the coast (for mildew-prone, cool sites).

This Masterclass gives you a Sunset+USDA timing matrix, weekly checklist, Pest Management actions tuned to caterpillars/aphids, and five heirloom cultivars that perform from fog belt gardens to warmer valleys.

“GrowBot did some digging… Head quality = even growth. Compost + mulch + steady drip beat heavy feeding.”

Sunset + USDA timing matrix (do now)

Sunset 17 (fog belt; USDA ~10): Transplant Sep–Oct; steady moisture; airflow to limit mildew.
Sunset 16 (coastal thermal): Transplant Sep–Oct; spring sets possible; light afternoon shade if a warm spell hits.
Sunset 14–15 (inland marine; USDA 9): Transplant late Aug–Sep; spring sets bolt early—harvest small/quick.

Hand-drawn broccoli tactics panel: coast icon with airflow arrows, inland sun with light shade cloth, and a labeled drip line for even moisture

Weekly checklist (fall start)

Week 0: Clear bed; 1–2” compost; set drip; pre-irrigate; mulch 2–3”.
Week 1: Transplant at 18”; install lightweight row cover.
Week 2–3: Scout for eggs/frass; hand-pick; spot-treat small larvae with Bt.
Week 4+: Harvest tight heads; then side shoots twice weekly.

Targeted Pest Management

Caterpillars (ICW/looper/DBM): exclude early; hand-pick; Bt on small larvae.
Aphids: knock back with water; manage ants; oils/soaps if needed; conserve natural enemies.
Powdery mildew (late): morning water + airflow.

Hand-drawn brassica pest panel with numbered callouts: 1) white butterfly, 2) green frass pellets on leaf, 3) translucent row cover edge

Heirloom Varieties for the Bay Area:

‘De Cicco’ — early, prolific side-shoots; reliable near coast and inland shoulder seasons.
‘Waltham 29’ — cool-tolerant heads; great for late fall inland.
‘Calabrese’ — classic open-pollinated; steady in variable temps.
‘Purple Sprouting’ — overwinters in mild pockets; many side-shoots.
‘Romanesco’ — fractal heads; wants even moisture and cool finish.