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When to Plant Sunflower in Amador County, CA

Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

Amador County, California is in USDA Zone 8a. The average last spring frost is March 8 and the first fall frost is November 25, giving you a growing season of approximately 262 days.

At an elevation of 1,335 feet, Amador County receives approximately 42.7 inches of rainfall annually with predominantly loam soil. Summer highs average 89ยฐF, providing good warmth for Sunflower during the growing season.

Amador County, CA (Zone 8a) Long season
262 days
Last Spring Frost March 8
262 growing days
First Fall Frost November 25

Amador County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (144 days to spare)
Start indoors: Dec 18 Transplant: Feb 19 🍅 Harvest: Apr 30 – Jun 18
Recommended (50%) ✓ Fits season (129 days to spare)
Start indoors: Jan 18 Transplant: Mar 22 🍅 Harvest: May 31 – Jul 19
Safe Start (90%) ✓ Fits season (111 days to spare)
Start indoors: Mar 1 Transplant: May 3 🍅 Harvest: Jul 12 – Aug 30

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Sunflower needs ~1,424 GDD — county provides 4,388 GDD Excellent fit

Sunflower Planting Timeline โ€” Amador County, CA

Sunflower Planting Calendar

Activity When Date Range
Start Indoors January 18 Jan 18 โ€“ Feb 1
Transplant Outdoors March 22 Mar 22 โ€“ Apr 5
Direct Sow March 15 Mar 15 โ€“ Apr 5
Harvest May 31 May 31 โ€“ Jul 19

Plant 1" deep ยท 18" apart ยท Rows 30" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July Harvest
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

70โ€“100 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 8a

Growing Season

262 days

Growing Tips for Amador County

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Sunflower in Amador County, CA?

Amador County is in Zone 8a with an average last frost of March 8. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Amador County, CA?

Amador County, California is in USDA Hardiness Zone 8a. The average last spring frost is March 8 and first fall frost is November 25.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Amador County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Amador County, CA. Local conditions may vary. Last updated: April 2026.