When to plant brussels sprouts in USDA Zone 9b

Plan your brussels sprouts planting around local frost risk and soil temperature, then work backward from the harvest week your buyers need. The calendar below is a starting point, not a field-level weather forecast.

Orlando, Tampa, San Antonio, southern LA coast. Average last spring frost February 5, first fall frost December 15 — a 313-day frost-free season.

Zone fit: challenging
Brussels sprouts need sustained cool weather for tight sprouts — Zone 9 heat often causes loose, open buds.

Key dates

Start seeds indoors
December 18 – January 1
Transplant outdoors
January 15 – February 5
Expected first harvest
May 2 – May 30
Fall planting window
August 4 – August 25
Fall harvest window
November 19 – December 17

Windows are calculated from your zone's average frost dates. Adjust ±1 week for microclimates, elevation, and your own frost records.

Spacing and soil

Plant spacing
24″
Row spacing
36″
Seed depth
0.25″
Soil temperature
55–75°F
Frost tolerance
hardy
Days to harvest
100 days

Grower notes for Zone 9b

Fall-only crop in the Southeast. Top the plant 4 weeks before target harvest for uniform sprouts up the stem.

Plant near: onions, dill

Keep away from: strawberries

Other brassicas for Zone 9b

Same crop, other zones

Track your own plantings

BAU Farm Intelligence turns these windows into per-field tasks — indoor seed-start reminders, transplant dates, harvest projections — using your farm's actual frost history.