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When to Plant Sunflower in Camas County, ID

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.

Camas County, Idaho is in USDA Zone 5a. The average last spring frost is May 3 and the first fall frost is October 3, giving you a growing season of approximately 153 days.

At an elevation of 5,406 feet, Camas County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Sunflower during the growing season.

Camas County, ID (Zone 5a) Moderate season
153 days
Last Spring Frost May 3
153 growing days
First Fall Frost October 3

Camas County Soil Profile

Soil Type

Loam

Soil pH

6.4-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (18 days to spare)
Start indoors: Mar 4 Transplant: May 13 🍅 Harvest: Jul 22 – Sep 9
Recommended (50%) ✓ Fits season (20 days to spare)
Start indoors: Mar 8 Transplant: May 17 🍅 Harvest: Jul 26 – Sep 13
Safe Start (90%) ✓ Fits season (9 days to spare)
Start indoors: Apr 6 Transplant: Jun 15 🍅 Harvest: Aug 24 – Oct 12

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
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Sunflower needs ~1,296 GDD — county provides 2,333 GDD Excellent fit

Sunflower Planting Timeline โ€” Camas County, ID

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 โ€“ Mar 22
Transplant Outdoors May 17 May 17 โ€“ May 31
Direct Sow May 10 May 10 โ€“ May 31
Harvest July 26 Jul 26 โ€“ Sep 13

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April โ€”
May Transplant Outdoors Direct Sow
June โ€”
July Harvest
August Harvest
September Harvest
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 5a

Growing Season

153 days

Growing Tips for Camas 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 Camas County, ID?

Camas County is in Zone 5a with an average last frost of May 3. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Camas County, ID?

Camas County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 3 and first fall frost is October 3.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Camas County gardeners in Zone 5a 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 Camas County, ID. Local conditions may vary. Last updated: April 2026.