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When to Plant Feverfew in Shelby 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.

Shelby County, Iowa is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 3, giving you a growing season of approximately 156 days.

At an elevation of 1,113 feet, Shelby County receives approximately 30.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Feverfew during the growing season.

Shelby County, IA (Zone 5a) Moderate season
156 days
Last Spring Frost April 30
156 growing days
First Fall Frost October 3

Shelby County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Apr 30 🍅 Harvest: Jul 30 – Oct 15
Recommended (50%) ✗ May not fit
Transplant: May 7 🍅 Harvest: Aug 6 – Oct 22
Safe Start (90%) ✗ May not fit
Transplant: May 22 🍅 Harvest: Aug 21 – Nov 6

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.

Soil Compatibility in Shelby County

How your county's soil matches Feverfew's growing requirements.

Soil pH

Your soil pH (6.2โ€“7.0) is within Feverfew's preferred range (6.0โ€“7.0).

Soil Texture

The silt loam soil in Shelby County is excellent for Feverfew โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.1%) โ€” Feverfew will thrive.

How to Plant Feverfew

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

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

Monthly Watering Guide for Feverfew

Feverfew needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Feverfew Needs Rainfall You Supplement Action
Jan โ€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 1.1" 0" โ„๏ธ Dormant
Mar โ€” 2.1" 0" โ„๏ธ Dormant
Apr 2.2" 2.8" 0" โœ… Rainfall sufficient
May 2.2" 3.7" 0" โœ… Rainfall sufficient
Jun 2.2" 3.8" 0" โœ… Rainfall sufficient
Jul 2.2" 3.5" 0" โœ… Rainfall sufficient
Aug 2.2" 2.9" 0" โœ… Rainfall sufficient
Sep 2.2" 2.8" 0" โœ… Rainfall sufficient
Oct 2.2" 2.5" 0" โœ… Rainfall sufficient
Nov โ€” 2" 0" โ„๏ธ Dormant
Dec โ€” 1.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Shelby County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Feverfew Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Feverfew needs ~1,522 GDD — county provides 2,262 GDD Excellent fit

Feverfew Planting Timeline โ€” Shelby County, IA

Feverfew Planting Calendar

Activity When Date Range
Transplant Outdoors May 7 May 7 โ€“ May 21
Harvest August 6 Aug 6 โ€“ Oct 22

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

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

156 days in Shelby County

Growing Tips for Feverfew in Shelby County

Direct sow Feverfew outdoors after April 30 in Shelby County when soil has warmed and frost danger has passed.

Common pests for Feverfew in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Feverfew in Shelby County, IA?

Shelby County is in Zone 5a with an average last frost of April 30. Plan your Feverfew planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Shelby County, IA?

Shelby County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 3.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

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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 Shelby County, IA. Local conditions may vary. Last updated: April 2026.