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When to Plant Feverfew in Warren 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.

Warren County, Iowa is in USDA Zone 5a. The average last spring frost is April 26 and the first fall frost is October 9, giving you a growing season of approximately 166 days.

At an elevation of 853 feet, Warren County receives approximately 30.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Feverfew during the growing season.

Warren County, IA (Zone 5a) Moderate season
166 days
Last Spring Frost April 26
166 growing days
First Fall Frost October 9

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 25 🍅 Harvest: Jul 25 – Oct 10
Recommended (50%) ✗ May not fit
Transplant: May 3 🍅 Harvest: Aug 2 – Oct 18
Safe Start (90%) ✗ May not fit
Transplant: May 18 🍅 Harvest: Aug 17 – Nov 2

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
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Feverfew needs ~1,601 GDD — county provides 2,531 GDD Excellent fit

Feverfew Planting Timeline โ€” Warren 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 5a

Growing Season

166 days

Growing Tips for Warren 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 Warren County, IA?

Warren County is in Zone 5a 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 Warren County, IA?

Warren County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 26 and first fall frost is October 9.

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Plan Your Garden with Confidence

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