When to Plant Brussels Sprouts in Simi Valley, CA
Published: April 24, 2026
Brussels Sprout Planting Dates for Simi Valley, CA
| Start seeds indoors | January 25–February 1 |
| Last frost (average) | March 1 |
| Transplant outdoors | May 24–June 3 |
| Minimum soil temperature | 45°F |
| Expect first harvest | August 12 – September 1 |
| Fall crop planting | August 23–September 2 |
| Fall crop harvest | November 11 |
| First fall frost (average) | November 22 |
⚠ Brussels sprouts are planted in midsummer for a fall harvest. Count back 90 days from your first fall frost to find the transplant date. Start seeds indoors 4–6 weeks before that date. Flavor improves after frost.
Best Brussels Sprout Varieties for Simi Valley, CA
Consult a Simi Valley-area nursery or your state extension office for brussels sprout varieties proven in Zone 7b.
Growing Brussels Sprouts in Simi Valley
Simi Valley sits in Zone 7b, with an average last frost of March 1 and first fall frost around November 22 — giving a 266-day frost-free growing season. Cool-season crops like brussels sprout benefit from Simi Valley's cooler spring and fall windows, when temperatures stay in the 55–75°F sweet spot that produces the best flavor and least bolting.
Simi Valley's moderate climate supports brussels sprout on the standard transplant calendar with minimal special accommodation. Succession planting — sowing fresh seeds or setting new transplants every 2–3 weeks through spring — stretches the harvest window and gives you a backup crop if pests hit the first planting.
Simi Valley's mixed soil conditions vary block by block — get a soil test if you have not in three years. Generally, a base of quality compost (2 to 3 inches annually) and consistent watering at 1.5 inches per week serves brussels sprout well across most soil types found in Simi Valley.
Brussels Sprout Calendar for Simi Valley
| Month | Task |
|---|---|
| January | Start seeds indoors under grow lights |
| March | Last frost — harden off seedlings outdoors |
| May | Transplant outdoors into warm soil |
| August | Expect first harvest window to open |
| August | Start fall crop — transplants or direct sow |
| November | First fall frost — harvest remaining, end of outdoor season |
Brussels Sprout Tips for Simi Valley Gardeners
- •Count back 90 days from first fall frost to find the transplant date — this is the most important Brussels sprout timing rule.
- •Pinch the top of each plant about a month before first frost — this channels energy into sprout formation.
- •Succession plant brussels sprout in Simi Valley every 2–3 weeks through spring to extend the harvest window into summer.
Common Brussels Sprout Pests in Simi Valley
- •Cabbage Worm — peaks July in Zone 7b (active May–September); green caterpillars on brassicas; apply Bt spray or use row covers.
- •Aphid — peaks July in Zone 7b (active May–September); monitor closely during peak season and treat early.
- •Cabbage Looper — peaks July in Zone 7b (active May–September); loop-walking green caterpillars; Bt spray works well.
Check plants every 2–3 days during peak season — early intervention prevents most infestations from becoming serious.
What to Plant with Brussels Sprouts in Simi Valley
In Simi Valley's moderate climate, Onion and Celery are the most beneficial plants to grow alongside brussels sprout. Onion deters carrot fly, aphids, and several root-zone pests through sulfur compounds. Keep brussels sprout away from Tomato — it competes for nutrients or shares pest pressure.
Frequently Asked Questions
When should I plant brussels sprout in Simi Valley, CA?
In Simi Valley (Zone 7b), start brussels sprout seeds indoors around January 25–February 1 and transplant outdoors around May 24–June 3. The city's average last frost of March 1 is the anchor date — count 5 weeks back for seed starting and 12 weeks forward for transplanting.
What zone is Simi Valley, CA for brussels sprout growing?
Simi Valley is USDA Zone 7b. For brussels sprout, this means a frost-free growing season of roughly 38 weeks running from March 1 to November 22. Cool-season crops like brussels sprout thrive in this zone with both spring and fall planting windows available.
When is brussels sprout harvest season in Simi Valley?
Expect the first brussels sprout harvest in Simi Valley around August 12, with harvest continuing through September 1. This is based on 80–100 days from transplant or direct sow. A fall crop planted August 23–September 2 adds a second harvest around November 11.
How long does it take to grow brussels sprout in Simi Valley, CA?
From transplant or direct sow to first harvest, brussels sprout takes 80–100 days in Simi Valley's climate. Based on a typical planting date of May 24–June 3, expect your first harvest around August 12. Simi Valley's Zone 7b transition-zone climate produces maturity times right in the middle of the stated range.
What soil does brussels sprout need in Simi Valley?
Simi Valley's soil conditions vary block by block. Before planting brussels sprout, do a soil test (most state extension offices run them for $15–30). The test reveals pH, key nutrient levels, and organic matter content, so you can amend appropriately rather than guessing. Generally, 2–3 inches of compost annually improves most soils for vegetable production.