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When to Plant Feverfew in Mills County, IA

Feverfew is a bushy perennial herb with small daisy-like flowers and aromatic leaves. It has been used traditionally for headache relief and is a cheerful garden plant.

Mills County, Iowa is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 7, giving you a growing season of approximately 164 days.

At an elevation of 1,355 feet, Mills County receives approximately 35.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Feverfew during the growing season.

Mills County, IA (Zone 5b) Moderate season
164 days
Last Spring Frost April 26
164 growing days
First Fall Frost October 7

Mills County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 29 🍅 Harvest: Jul 29 – Oct 14
Recommended (50%) ✗ May not fit
Transplant: May 3 🍅 Harvest: Aug 2 – Oct 18
Safe Start (90%) ✗ May not fit
Transplant: May 19 🍅 Harvest: Aug 18 – Nov 3

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
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Feverfew needs ~1,444 GDD — county provides 2,255 GDD Excellent fit

Feverfew Planting Timeline โ€” Mills County, IA

Feverfew Planting Calendar

Activity When Date Range
Transplant Outdoors May 3 May 3 โ€“ May 17
Harvest August 2 Aug 2 โ€“ Oct 18

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

90โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

164 days

Growing Tips for Mills County

Start seeds indoors or direct sow on the soil surface. Deadhead regularly to prevent aggressive self-seeding. Divide clumps every 2-3 years to maintain vigor.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Feverfew in Mills County, IA?

Mills County is in Zone 5b with an average last frost of April 26. Plan your Feverfew planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Mills County, IA?

Mills County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Mills County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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